Complete LinkedChildren integration and batch DTO optimizations

This commit integrates remaining performance changes:

- Add batch user data fetching in DtoService to reduce N+1 queries
- Add GetNextUpEpisodesBatch in TVSeriesManager for efficient batch retrieval
- Update Video/Movie/BoxSet to use LibraryManager for alternate versions
- Transition LinkedChild to use ItemId instead of Path (obsolete Path/LibraryItemId)
- Update providers and controllers for LinkedChildren-based references
- Add NextUpEpisodeBatchResult for batched episode queries
- Integrate IDescendantQueryProvider in SqliteDatabaseProvider

35 files changed, 2242 insertions, 901 deletions

diff --git a/Emby.Server.Implementations/Collections/CollectionManager.cs b/Emby.Server.Implementations/Collections/CollectionManager.cs
index a320a774c6..0ede5665f9 100644
--- a/Emby.Server.Implementations/Collections/CollectionManager.cs
+++ b/Emby.Server.Implementations/Collections/CollectionManager.cs
@@ -272,7 +272,7 @@ namespace Emby.Server.Implementations.Collections
             {
                 var childItem = _libraryManager.GetItemById(guidId);
 
-                var child = collection.LinkedChildren.FirstOrDefault(i => (i.ItemId.HasValue && i.ItemId.Value.Equals(guidId)) || (childItem is not null && string.Equals(childItem.Path, i.Path, StringComparison.OrdinalIgnoreCase)));
+                var child = collection.LinkedChildren.FirstOrDefault(i => i.ItemId.HasValue && i.ItemId.Value.Equals(guidId));
 
                 if (child is null)
                 {
@@ -342,7 +342,7 @@ namespace Emby.Server.Implementations.Collections
                     // this is kind of a performance hack because only Video has alternate versions that should be in a box set?
                     if (item is Video video)
                     {
-                        foreach (var childId in video.GetLocalAlternateVersionIds())
+                        foreach (var childId in _libraryManager.GetLocalAlternateVersionIds(video))
                         {
                             if (!results.ContainsKey(childId))
                             {
diff --git a/Emby.Server.Implementations/Dto/DtoService.cs b/Emby.Server.Implementations/Dto/DtoService.cs
index c5dc3b054c..236b3fabe4 100644
--- a/Emby.Server.Implementations/Dto/DtoService.cs
+++ b/Emby.Server.Implementations/Dto/DtoService.cs
@@ -153,17 +153,42 @@ namespace Emby.Server.Implementations.Dto
         private ILiveTvManager LivetvManager => _livetvManagerFactory.Value;
 
         /// <inheritdoc />
-        public IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null)
+        public IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null, bool skipVisibilityCheck = false)
         {
-            var accessibleItems = user is null ? items : items.Where(x => x.IsVisible(user)).ToList();
+            var accessibleItems = skipVisibilityCheck || user is null ? items : items.Where(x => x.IsVisible(user)).ToList();
             var returnItems = new BaseItemDto[accessibleItems.Count];
             List<(BaseItem, BaseItemDto)>? programTuples = null;
             List<(BaseItemDto, LiveTvChannel)>? channelTuples = null;
 
+            // Batch-fetch user data for all items
+            Dictionary<Guid, UserItemData>? userDataBatch = null;
+            if (user is not null && options.EnableUserData)
+            {
+                userDataBatch = _userDataRepository.GetUserDataBatch(accessibleItems, user);
+            }
+
+            // Pre-compute collection folders once to avoid N+1 queries in CanDelete
+            List<Folder>? allCollectionFolders = null;
+            if (user is not null && options.ContainsField(ItemFields.CanDelete))
+            {
+                allCollectionFolders = _libraryManager.GetUserRootFolder().Children.OfType<Folder>().ToList();
+            }
+
+            // Batch-fetch child counts for all folders to avoid N+1 queries
+            Dictionary<Guid, int>? childCountBatch = null;
+            if (options.ContainsField(ItemFields.ChildCount))
+            {
+                var folderIds = accessibleItems.OfType<Folder>().Select(f => f.Id).ToList();
+                if (folderIds.Count > 0)
+                {
+                    childCountBatch = _libraryManager.GetChildCountBatch(folderIds, user?.Id);
+                }
+            }
+
             for (int index = 0; index < accessibleItems.Count; index++)
             {
                 var item = accessibleItems[index];
-                var dto = GetBaseItemDtoInternal(item, options, user, owner);
+                var dto = GetBaseItemDtoInternal(item, options, user, owner, userDataBatch?.GetValueOrDefault(item.Id), allCollectionFolders, childCountBatch);
 
                 if (item is LiveTvChannel tvChannel)
                 {
@@ -197,7 +222,7 @@ namespace Emby.Server.Implementations.Dto
 
         public BaseItemDto GetBaseItemDto(BaseItem item, DtoOptions options, User? user = null, BaseItem? owner = null)
         {
-            var dto = GetBaseItemDtoInternal(item, options, user, owner);
+            var dto = GetBaseItemDtoInternal(item, options, user, owner, null);
             if (item is LiveTvChannel tvChannel)
             {
                 LivetvManager.AddChannelInfo(new[] { (dto, tvChannel) }, options, user);
@@ -215,7 +240,7 @@ namespace Emby.Server.Implementations.Dto
             return dto;
         }
 
-        private BaseItemDto GetBaseItemDtoInternal(BaseItem item, DtoOptions options, User? user = null, BaseItem? owner = null)
+        private BaseItemDto GetBaseItemDtoInternal(BaseItem item, DtoOptions options, User? user = null, BaseItem? owner = null, UserItemData? userData = null, List<Folder>? allCollectionFolders = null, Dictionary<Guid, int>? childCountBatch = null)
         {
             var dto = new BaseItemDto
             {
@@ -252,7 +277,7 @@ namespace Emby.Server.Implementations.Dto
 
             if (user is not null)
             {
-                AttachUserSpecificInfo(dto, item, user, options);
+                AttachUserSpecificInfo(dto, item, user, options, userData, childCountBatch);
             }
 
             if (item is IHasMediaSources
@@ -274,7 +299,9 @@ namespace Emby.Server.Implementations.Dto
             {
                 dto.CanDelete = user is null
                     ? item.CanDelete()
-                    : item.CanDelete(user);
+                    : allCollectionFolders is not null
+                        ? item.CanDelete(user, allCollectionFolders)
+                        : item.CanDelete(user);
             }
 
             if (options.ContainsField(ItemFields.CanDownload))
@@ -458,7 +485,7 @@ namespace Emby.Server.Implementations.Dto
         /// <summary>
         /// Attaches the user specific info.
         /// </summary>
-        private void AttachUserSpecificInfo(BaseItemDto dto, BaseItem item, User user, DtoOptions options)
+        private void AttachUserSpecificInfo(BaseItemDto dto, BaseItem item, User user, DtoOptions options, UserItemData? userData = null, Dictionary<Guid, int>? childCountBatch = null)
         {
             if (item.IsFolder)
             {
@@ -466,7 +493,17 @@ namespace Emby.Server.Implementations.Dto
 
                 if (options.EnableUserData)
                 {
-                    dto.UserData = _userDataRepository.GetUserDataDto(item, dto, user, options);
+                    if (userData is not null)
+                    {
+                        // Use pre-fetched user data
+                        dto.UserData = GetUserItemDataDto(userData, item.Id);
+                        item.FillUserDataDtoValues(dto.UserData, userData, dto, user, options);
+                    }
+                    else
+                    {
+                        // Fall back to individual fetch
+                        dto.UserData = _userDataRepository.GetUserDataDto(item, dto, user, options);
+                    }
                 }
 
                 if (!dto.ChildCount.HasValue && item.SourceType == SourceType.Library)
@@ -485,7 +522,7 @@ namespace Emby.Server.Implementations.Dto
 
                     if (options.ContainsField(ItemFields.ChildCount))
                     {
-                        dto.ChildCount ??= GetChildCount(folder, user);
+                        dto.ChildCount ??= GetChildCount(folder, user, childCountBatch);
                     }
                 }
 
@@ -503,7 +540,17 @@ namespace Emby.Server.Implementations.Dto
             {
                 if (options.EnableUserData)
                 {
-                    dto.UserData = _userDataRepository.GetUserDataDto(item, user);
+                    if (userData is not null)
+                    {
+                        // Use pre-fetched user data
+                        dto.UserData = GetUserItemDataDto(userData, item.Id);
+                        item.FillUserDataDtoValues(dto.UserData, userData, dto, user, options);
+                    }
+                    else
+                    {
+                        // Fall back to individual fetch
+                        dto.UserData = _userDataRepository.GetUserDataDto(item, user);
+                    }
                 }
             }
 
@@ -513,7 +560,25 @@ namespace Emby.Server.Implementations.Dto
             }
         }
 
-        private static int GetChildCount(Folder folder, User user)
+        private static UserItemDataDto GetUserItemDataDto(UserItemData data, Guid itemId)
+        {
+            ArgumentNullException.ThrowIfNull(data);
+
+            return new UserItemDataDto
+            {
+                IsFavorite = data.IsFavorite,
+                Likes = data.Likes,
+                PlaybackPositionTicks = data.PlaybackPositionTicks,
+                PlayCount = data.PlayCount,
+                Rating = data.Rating,
+                Played = data.Played,
+                LastPlayedDate = data.LastPlayedDate,
+                ItemId = itemId,
+                Key = data.Key
+            };
+        }
+
+        private static int GetChildCount(Folder folder, User user, Dictionary<Guid, int>? childCountBatch)
         {
             // Right now this is too slow to calculate for top level folders on a per-user basis
             // Just return something so that apps that are expecting a value won't think the folders are empty
@@ -522,6 +587,13 @@ namespace Emby.Server.Implementations.Dto
                 return Random.Shared.Next(1, 10);
             }
 
+            // Use pre-fetched batch data if available
+            if (childCountBatch is not null && childCountBatch.TryGetValue(folder.Id, out var count))
+            {
+                return count;
+            }
+
+            // Fall back to individual query for special cases (Series, Season, etc.)
             return folder.GetChildCount(user);
         }
 
diff --git a/Emby.Server.Implementations/Library/LibraryManager.cs b/Emby.Server.Implementations/Library/LibraryManager.cs
index f7f5c387e1..2acfd68c36 100644
--- a/Emby.Server.Implementations/Library/LibraryManager.cs
+++ b/Emby.Server.Implementations/Library/LibraryManager.cs
@@ -406,6 +406,37 @@ namespace Emby.Server.Implementations.Library
                     item.Id);
             }
 
+            // If deleting a primary version video, clear PrimaryVersionId from alternate versions
+            if (item is Video video && string.IsNullOrEmpty(video.PrimaryVersionId))
+            {
+                var alternateVersions = GetLocalAlternateVersionIds(video)
+                    .Concat(GetLinkedAlternateVersions(video).Select(v => v.Id))
+                    .Distinct()
+                    .Select(id => GetItemById(id))
+                    .OfType<Video>()
+                    .ToList();
+
+                if (alternateVersions.Count > 0)
+                {
+                    _logger.LogInformation(
+                        "Clearing PrimaryVersionId from {Count} alternate versions of {Name}",
+                        alternateVersions.Count,
+                        item.Name ?? "Unknown name");
+
+                    // Promote the first alternate version to be the new primary
+                    var newPrimary = alternateVersions[0];
+                    newPrimary.SetPrimaryVersionId(null);
+                    newPrimary.UpdateToRepositoryAsync(ItemUpdateType.MetadataEdit, CancellationToken.None).GetAwaiter().GetResult();
+
+                    // Update remaining alternates to point to new primary
+                    foreach (var alternate in alternateVersions.Skip(1))
+                    {
+                        alternate.SetPrimaryVersionId(newPrimary.Id.ToString("N", CultureInfo.InvariantCulture));
+                        alternate.UpdateToRepositoryAsync(ItemUpdateType.MetadataEdit, CancellationToken.None).GetAwaiter().GetResult();
+                    }
+                }
+            }
+
             var children = item.IsFolder
                 ? ((Folder)item).GetRecursiveChildren(false)
                 : [];
@@ -576,6 +607,9 @@ namespace Emby.Server.Implementations.Library
                 // Trickplay
                 list.Add(_pathManager.GetTrickplayDirectory(video));
 
+                // Chapter Images
+                list.Add(_pathManager.GetChapterImageFolderPath(video));
+
                 // Subtitles and attachments
                 foreach (var mediaSource in item.GetMediaSources(false))
                 {
@@ -1421,14 +1455,7 @@ namespace Emby.Server.Implementations.Library
                 AddUserToQuery(query, query.User, allowExternalContent);
             }
 
-            var itemList = _itemRepository.GetItemList(query);
-            var user = query.User;
-            if (user is not null)
-            {
-                return itemList.Where(i => i.IsVisible(user)).ToList();
-            }
-
-            return itemList;
+            return _itemRepository.GetItemList(query);
         }
 
         public IReadOnlyList<BaseItem> GetItemList(InternalItemsQuery query)
@@ -1474,6 +1501,11 @@ namespace Emby.Server.Implementations.Library
             return _itemRepository.GetItemCounts(query);
         }
 
+        public Dictionary<Guid, int> GetChildCountBatch(IReadOnlyList<Guid> parentIds, Guid? userId)
+        {
+            return _itemRepository.GetChildCountBatch(parentIds, userId);
+        }
+
         public IReadOnlyList<BaseItem> GetItemList(InternalItemsQuery query, List<BaseItem> parents)
         {
             SetTopParentIdsOrAncestors(query, parents);
@@ -1519,6 +1551,16 @@ namespace Emby.Server.Implementations.Library
             return _itemRepository.GetNextUpSeriesKeys(query, dateCutoff);
         }
 
+        /// <inheritdoc />
+        public IReadOnlyDictionary<string, MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult> GetNextUpEpisodesBatch(
+            InternalItemsQuery query,
+            IReadOnlyList<string> seriesKeys,
+            bool includeSpecials,
+            bool includeWatchedForRewatching)
+        {
+            return _itemRepository.GetNextUpEpisodesBatch(query, seriesKeys, includeSpecials, includeWatchedForRewatching);
+        }
+
         public QueryResult<BaseItem> QueryItems(InternalItemsQuery query)
         {
             if (query.User is not null)
@@ -1700,6 +1742,11 @@ namespace Emby.Server.Implementations.Library
 
         private void AddUserToQuery(InternalItemsQuery query, User user, bool allowExternalContent = true)
         {
+            if (query.User is null)
+            {
+                query.SetUser(user);
+            }
+
             if (query.AncestorIds.Length == 0 &&
                 query.ParentId.IsEmpty() &&
                 query.ChannelIds.Count == 0 &&
@@ -1725,6 +1772,15 @@ namespace Emby.Server.Implementations.Library
             }
         }
 
+        /// <inheritdoc/>
+        public void ConfigureUserAccess(InternalItemsQuery query, User user)
+        {
+            ArgumentNullException.ThrowIfNull(query);
+            ArgumentNullException.ThrowIfNull(user);
+
+            AddUserToQuery(query, user);
+        }
+
         private IEnumerable<Guid> GetTopParentIdsForQuery(BaseItem item, User? user)
         {
             if (item is UserView view)
@@ -1890,6 +1946,38 @@ namespace Emby.Server.Implementations.Library
         }
 
         /// <inheritdoc />
+        public IEnumerable<Guid> GetLocalAlternateVersionIds(Video video)
+        {
+            ArgumentNullException.ThrowIfNull(video);
+
+            var linkedIds = _itemRepository.GetLinkedChildrenIds(video.Id, (int)MediaBrowser.Controller.Entities.LinkedChildType.LocalAlternateVersion);
+            if (linkedIds.Count > 0)
+            {
+                return linkedIds;
+            }
+
+            return [];
+        }
+
+        /// <inheritdoc />
+        public IEnumerable<Video> GetLinkedAlternateVersions(Video video)
+        {
+            ArgumentNullException.ThrowIfNull(video);
+
+            var linkedIds = _itemRepository.GetLinkedChildrenIds(video.Id, (int)MediaBrowser.Controller.Entities.LinkedChildType.LinkedAlternateVersion);
+            if (linkedIds.Count > 0)
+            {
+                return linkedIds
+                    .Select(id => GetItemById(id))
+                    .Where(i => i is not null)
+                    .OfType<Video>()
+                    .OrderBy(i => i.SortName);
+            }
+
+            return [];
+        }
+
+        /// <inheritdoc />
         public IEnumerable<BaseItem> Sort(IEnumerable<BaseItem> items, User? user, IEnumerable<ItemSortBy> sortBy, SortOrder sortOrder)
         {
             IOrderedEnumerable<BaseItem>? orderedItems = null;
@@ -2896,10 +2984,17 @@ namespace Emby.Server.Implementations.Library
                     extra.ExtraType = extraType;
                 }
 
-                extra.ParentId = Guid.Empty;
-                extra.OwnerId = owner.Id;
-                extra.IsInMixedFolder = isInMixedFolder;
-                return extra;
+                // Only set OwnerId if this is actually an extra (not Unknown or null)
+                if (extra.ExtraType is not null)
+                {
+                    extra.ParentId = Guid.Empty;
+                    extra.OwnerId = owner.Id;
+                    extra.IsInMixedFolder = isInMixedFolder;
+
+                    return extra;
+                }
+
+                return null;
             }
         }
 
diff --git a/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanupCollectionAndPlaylistPathsTask.cs b/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanupCollectionAndPlaylistPathsTask.cs
index 7f68f7701e..1c2038d839 100644
--- a/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanupCollectionAndPlaylistPathsTask.cs
+++ b/Emby.Server.Implementations/ScheduledTasks/Tasks/CleanupCollectionAndPlaylistPathsTask.cs
@@ -1,9 +1,9 @@
 using System;
 using System.Collections.Generic;
-using System.IO;
 using System.Linq;
 using System.Threading;
 using System.Threading.Tasks;
+using Jellyfin.Extensions;
 using MediaBrowser.Controller.Collections;
 using MediaBrowser.Controller.Entities;
 using MediaBrowser.Controller.Entities.Movies;
@@ -11,7 +11,6 @@ using MediaBrowser.Controller.Library;
 using MediaBrowser.Controller.Playlists;
 using MediaBrowser.Controller.Providers;
 using MediaBrowser.Model.Globalization;
-using MediaBrowser.Model.IO;
 using MediaBrowser.Model.Tasks;
 using Microsoft.Extensions.Logging;
 
@@ -27,6 +26,7 @@ public class CleanupCollectionAndPlaylistPathsTask : IScheduledTask
     private readonly IPlaylistManager _playlistManager;
     private readonly ILogger<CleanupCollectionAndPlaylistPathsTask> _logger;
     private readonly IProviderManager _providerManager;
+    private readonly ILibraryManager _libraryManager;
 
     /// <summary>
     /// Initializes a new instance of the <see cref="CleanupCollectionAndPlaylistPathsTask"/> class.
@@ -36,18 +36,21 @@ public class CleanupCollectionAndPlaylistPathsTask : IScheduledTask
     /// <param name="playlistManager">Instance of the <see cref="IPlaylistManager"/> interface.</param>
     /// <param name="logger">Instance of the <see cref="ILogger"/> interface.</param>
     /// <param name="providerManager">Instance of the <see cref="IProviderManager"/> interface.</param>
+    /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
     public CleanupCollectionAndPlaylistPathsTask(
         ILocalizationManager localization,
         ICollectionManager collectionManager,
         IPlaylistManager playlistManager,
         ILogger<CleanupCollectionAndPlaylistPathsTask> logger,
-        IProviderManager providerManager)
+        IProviderManager providerManager,
+        ILibraryManager libraryManager)
     {
         _localization = localization;
         _collectionManager = collectionManager;
         _playlistManager = playlistManager;
         _logger = logger;
         _providerManager = providerManager;
+        _libraryManager = libraryManager;
     }
 
     /// <inheritdoc />
@@ -111,12 +114,15 @@ public class CleanupCollectionAndPlaylistPathsTask : IScheduledTask
         List<LinkedChild>? itemsToRemove = null;
         foreach (var linkedChild in folder.LinkedChildren)
         {
-            var path = linkedChild.Path;
-            if (!File.Exists(path) && !Directory.Exists(path))
+            if (linkedChild.ItemId.HasValue
+                && !linkedChild.ItemId.Value.IsEmpty()
+                && _libraryManager.GetItemById(linkedChild.ItemId.Value) is not null)
             {
-                _logger.LogInformation("Item in {FolderName} cannot be found at {ItemPath}", folder.Name, path);
-                (itemsToRemove ??= new List<LinkedChild>()).Add(linkedChild);
+                continue;
             }
+
+            _logger.LogInformation("Item in {FolderName} with ItemId {ItemId} no longer exists in library", folder.Name, linkedChild.ItemId);
+            (itemsToRemove ??= []).Add(linkedChild);
         }
 
         if (itemsToRemove is not null)
diff --git a/Emby.Server.Implementations/Session/SessionManager.cs b/Emby.Server.Implementations/Session/SessionManager.cs
index cf2ca047cf..6f576146e4 100644
--- a/Emby.Server.Implementations/Session/SessionManager.cs
+++ b/Emby.Server.Implementations/Session/SessionManager.cs
@@ -1820,7 +1820,6 @@ namespace Emby.Server.Implementations.Session
                 fields.Remove(ItemFields.Settings);
                 fields.Remove(ItemFields.SortName);
                 fields.Remove(ItemFields.Tags);
-                fields.Remove(ItemFields.ExtraIds);
 
                 dtoOptions.Fields = fields.ToArray();
 
diff --git a/Emby.Server.Implementations/TV/TVSeriesManager.cs b/Emby.Server.Implementations/TV/TVSeriesManager.cs
index cd98dbe86e..ebabb4ca2f 100644
--- a/Emby.Server.Implementations/TV/TVSeriesManager.cs
+++ b/Emby.Server.Implementations/TV/TVSeriesManager.cs
@@ -47,7 +47,7 @@ namespace Emby.Server.Implementations.TV
 
             if (!string.IsNullOrEmpty(presentationUniqueKey))
             {
-                return GetResult(GetNextUpEpisodes(query, user, new[] { presentationUniqueKey }, options), query);
+                return GetNextUpBatched(query, user, [presentationUniqueKey], options);
             }
 
             BaseItem[] parents;
@@ -58,11 +58,11 @@ namespace Emby.Server.Implementations.TV
 
                 if (parent is not null)
                 {
-                    parents = new[] { parent };
+                    parents = [parent];
                 }
                 else
                 {
-                    parents = Array.Empty<BaseItem>();
+                    parents = [];
                 }
             }
             else
@@ -93,7 +93,7 @@ namespace Emby.Server.Implementations.TV
 
             if (!string.IsNullOrEmpty(presentationUniqueKey))
             {
-                return GetResult(GetNextUpEpisodes(request, user, [presentationUniqueKey], options), request);
+                return GetNextUpBatched(request, user, [presentationUniqueKey], options);
             }
 
             if (limit.HasValue)
@@ -103,151 +103,138 @@ namespace Emby.Server.Implementations.TV
 
             var nextUpSeriesKeys = _libraryManager.GetNextUpSeriesKeys(new InternalItemsQuery(user) { Limit = limit }, parentsFolders, request.NextUpDateCutoff);
 
-            var episodes = GetNextUpEpisodes(request, user, nextUpSeriesKeys, options);
-
-            return GetResult(episodes, request);
+            return GetNextUpBatched(request, user, nextUpSeriesKeys, options);
         }
 
-        private IEnumerable<Episode> GetNextUpEpisodes(NextUpQuery request, User user, IReadOnlyList<string> seriesKeys, DtoOptions dtoOptions)
+        private QueryResult<BaseItem> GetNextUpBatched(NextUpQuery request, User user, IReadOnlyList<string> seriesKeys, DtoOptions dtoOptions)
         {
-            var allNextUp = seriesKeys.Select(i => GetNextUp(i, user, dtoOptions, request.EnableResumable, false));
-
-            if (request.EnableRewatching)
+            if (seriesKeys.Count == 0)
             {
-                allNextUp = allNextUp
-                    .Concat(seriesKeys.Select(i => GetNextUp(i, user, dtoOptions, false, true)))
-                    .OrderByDescending(i => i.LastWatchedDate);
+                return new QueryResult<BaseItem>();
             }
 
-            return allNextUp
-                .Select(i => i.GetEpisodeFunction())
-                .Where(i => i is not null)!;
-        }
-
-        private static string GetUniqueSeriesKey(Series series)
-        {
-            return series.GetPresentationUniqueKey();
-        }
+            var includeSpecials = _configurationManager.Configuration.DisplaySpecialsWithinSeasons;
+            var includeRewatching = request.EnableRewatching;
 
-        /// <summary>
-        /// Gets the next up.
-        /// </summary>
-        /// <returns>Task{Episode}.</returns>
-        private (DateTime LastWatchedDate, Func<Episode?> GetEpisodeFunction) GetNextUp(string seriesKey, User user, DtoOptions dtoOptions, bool includeResumable, bool includePlayed)
-        {
-            var lastQuery = new InternalItemsQuery(user)
+            var query = new InternalItemsQuery(user)
             {
-                AncestorWithPresentationUniqueKey = null,
-                SeriesPresentationUniqueKey = seriesKey,
-                IncludeItemTypes = [BaseItemKind.Episode],
-                IsPlayed = true,
-                Limit = 1,
-                ParentIndexNumberNotEquals = 0,
-                DtoOptions = new DtoOptions
-                {
-                    Fields = [ItemFields.SortName],
-                    EnableImages = false
-                }
+                DtoOptions = dtoOptions
             };
 
-            // If including played results, sort first by date played and then by season and episode numbers
-            lastQuery.OrderBy = includePlayed
-                ? new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.ParentIndexNumber, SortOrder.Descending), (ItemSortBy.IndexNumber, SortOrder.Descending) }
-                : new[] { (ItemSortBy.ParentIndexNumber, SortOrder.Descending), (ItemSortBy.IndexNumber, SortOrder.Descending) };
+            var batchResult = _libraryManager.GetNextUpEpisodesBatch(query, seriesKeys, includeSpecials, includeRewatching);
 
-            var lastWatchedEpisode = _libraryManager.GetItemList(lastQuery).Cast<Episode>().FirstOrDefault();
+            var nextUpList = new List<(DateTime LastWatchedDate, Episode Episode)>();
 
-            Episode? GetEpisode()
+            foreach (var seriesKey in seriesKeys)
             {
-                var nextQuery = new InternalItemsQuery(user)
+                if (!batchResult.TryGetValue(seriesKey, out var result))
                 {
-                    AncestorWithPresentationUniqueKey = null,
-                    SeriesPresentationUniqueKey = seriesKey,
-                    IncludeItemTypes = [BaseItemKind.Episode],
-                    OrderBy = [(ItemSortBy.ParentIndexNumber, SortOrder.Ascending), (ItemSortBy.IndexNumber, SortOrder.Ascending)],
-                    Limit = 1,
-                    IsPlayed = includePlayed,
-                    IsVirtualItem = false,
-                    ParentIndexNumberNotEquals = 0,
-                    DtoOptions = dtoOptions
-                };
-
-                // Locate the next up episode based on the last watched episode's season and episode number
-                var lastWatchedParentIndexNumber = lastWatchedEpisode?.ParentIndexNumber;
-                var lastWatchedIndexNumber = lastWatchedEpisode?.IndexNumberEnd ?? lastWatchedEpisode?.IndexNumber;
-                if (lastWatchedParentIndexNumber.HasValue && lastWatchedIndexNumber.HasValue)
-                {
-                    nextQuery.MinParentAndIndexNumber = (lastWatchedParentIndexNumber.Value, lastWatchedIndexNumber.Value + 1);
+                    continue;
                 }
 
-                var nextEpisode = _libraryManager.GetItemList(nextQuery).Cast<Episode>().FirstOrDefault();
+                var nextEpisode = DetermineNextEpisode(result, user, includeSpecials, request.EnableResumable, false);
 
-                if (_configurationManager.Configuration.DisplaySpecialsWithinSeasons)
+                if (nextEpisode is not null)
                 {
-                    var consideredEpisodes = _libraryManager.GetItemList(new InternalItemsQuery(user)
+                    DateTime lastWatchedDate = DateTime.MinValue;
+                    if (result.LastWatched is not null)
                     {
-                        AncestorWithPresentationUniqueKey = null,
-                        SeriesPresentationUniqueKey = seriesKey,
-                        ParentIndexNumber = 0,
-                        IncludeItemTypes = [BaseItemKind.Episode],
-                        IsPlayed = includePlayed,
-                        IsVirtualItem = false,
-                        DtoOptions = dtoOptions
-                    })
-                    .Cast<Episode>()
-                    .Where(episode => episode.AirsBeforeSeasonNumber is not null || episode.AirsAfterSeasonNumber is not null)
-                    .ToList();
-
-                    if (lastWatchedEpisode is not null)
-                    {
-                        // Last watched episode is added, because there could be specials that aired before the last watched episode
-                        consideredEpisodes.Add(lastWatchedEpisode);
+                        var userData = _userDataManager.GetUserData(user, result.LastWatched);
+                        lastWatchedDate = userData?.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
                     }
 
-                    if (nextEpisode is not null)
-                    {
-                        consideredEpisodes.Add(nextEpisode);
-                    }
+                    nextUpList.Add((lastWatchedDate, nextEpisode));
+                }
 
-                    var sortedConsideredEpisodes = _libraryManager.Sort(consideredEpisodes, user, [(ItemSortBy.AiredEpisodeOrder, SortOrder.Ascending)])
-                        .Cast<Episode>();
-                    if (lastWatchedEpisode is not null)
+                if (includeRewatching)
+                {
+                    var nextPlayedEpisode = DetermineNextEpisodeForRewatching(result, user, includeSpecials);
+
+                    if (nextPlayedEpisode is not null)
                     {
-                        sortedConsideredEpisodes = sortedConsideredEpisodes.SkipWhile(episode => !episode.Id.Equals(lastWatchedEpisode.Id)).Skip(1);
+                        DateTime rewatchLastWatchedDate = DateTime.MinValue;
+                        if (result.LastWatchedForRewatching is not null)
+                        {
+                            var userData = _userDataManager.GetUserData(user, result.LastWatchedForRewatching);
+                            rewatchLastWatchedDate = userData?.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
+                        }
+
+                        nextUpList.Add((rewatchLastWatchedDate, nextPlayedEpisode));
                     }
+                }
+            }
 
-                    nextEpisode = sortedConsideredEpisodes.FirstOrDefault();
+            var sortedEpisodes = nextUpList
+                .OrderByDescending(x => x.LastWatchedDate)
+                .Select(x => (BaseItem)x.Episode);
+
+            return GetResult(sortedEpisodes, request);
+        }
+
+        private Episode? DetermineNextEpisode(
+            MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult result,
+            User user,
+            bool includeSpecials,
+            bool includeResumable,
+            bool includePlayed)
+        {
+            var nextEpisode = (includePlayed ? result.NextPlayedForRewatching : result.NextUp) as Episode;
+            var lastWatchedEpisode = (includePlayed ? result.LastWatchedForRewatching : result.LastWatched) as Episode;
+
+            if (includeSpecials && result.Specials?.Count > 0)
+            {
+                var consideredEpisodes = result.Specials
+                    .Cast<Episode>()
+                    .Where(episode => episode.AirsBeforeSeasonNumber is not null || episode.AirsAfterSeasonNumber is not null)
+                    .ToList();
+
+                if (lastWatchedEpisode is not null)
+                {
+                    consideredEpisodes.Add(lastWatchedEpisode);
                 }
 
-                if (nextEpisode is not null && !includeResumable)
+                if (nextEpisode is not null)
                 {
-                    var userData = _userDataManager.GetUserData(user, nextEpisode);
+                    consideredEpisodes.Add(nextEpisode);
+                }
 
-                    if (userData?.PlaybackPositionTicks > 0)
+                if (consideredEpisodes.Count > 0)
+                {
+                    var sortedEpisodes = _libraryManager.Sort(consideredEpisodes, user, [(ItemSortBy.AiredEpisodeOrder, SortOrder.Ascending)])
+                        .Cast<Episode>();
+
+                    if (lastWatchedEpisode is not null)
                     {
-                        return null;
+                        sortedEpisodes = sortedEpisodes.SkipWhile(episode => !episode.Id.Equals(lastWatchedEpisode.Id)).Skip(1);
                     }
-                }
 
-                return nextEpisode;
+                    nextEpisode = sortedEpisodes.FirstOrDefault();
+                }
             }
 
-            if (lastWatchedEpisode is not null)
+            if (nextEpisode is not null && !includeResumable)
             {
-                var userData = _userDataManager.GetUserData(user, lastWatchedEpisode);
-
-                if (userData is null)
+                var userData = _userDataManager.GetUserData(user, nextEpisode);
+                if (userData?.PlaybackPositionTicks > 0)
                 {
-                    return (DateTime.MinValue, GetEpisode);
+                    return null;
                 }
+            }
 
-                var lastWatchedDate = userData.LastPlayedDate ?? DateTime.MinValue.AddDays(1);
+            return nextEpisode;
+        }
 
-                return (lastWatchedDate, GetEpisode);
-            }
+        private Episode? DetermineNextEpisodeForRewatching(
+            MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult result,
+            User user,
+            bool includeSpecials)
+        {
+            return DetermineNextEpisode(result, user, includeSpecials, includeResumable: false, includePlayed: true);
+        }
 
-            // Return the first episode
-            return (DateTime.MinValue, GetEpisode);
+        private static string GetUniqueSeriesKey(Series series)
+        {
+            return series.GetPresentationUniqueKey();
         }
 
         private static QueryResult<BaseItem> GetResult(IEnumerable<BaseItem> items, NextUpQuery query)
diff --git a/Jellyfin.Api/Controllers/LibraryController.cs b/Jellyfin.Api/Controllers/LibraryController.cs
index 558e1c6c80..cb0d449aa4 100644
--- a/Jellyfin.Api/Controllers/LibraryController.cs
+++ b/Jellyfin.Api/Controllers/LibraryController.cs
@@ -456,19 +456,18 @@ public class LibraryController : BaseJellyfinApiController
             ? null
             : _userManager.GetUserById(userId.Value);
 
-        var counts = new ItemCounts
+        var query = new InternalItemsQuery(user)
         {
-            AlbumCount = GetCount(BaseItemKind.MusicAlbum, user, isFavorite),
-            EpisodeCount = GetCount(BaseItemKind.Episode, user, isFavorite),
-            MovieCount = GetCount(BaseItemKind.Movie, user, isFavorite),
-            SeriesCount = GetCount(BaseItemKind.Series, user, isFavorite),
-            SongCount = GetCount(BaseItemKind.Audio, user, isFavorite),
-            MusicVideoCount = GetCount(BaseItemKind.MusicVideo, user, isFavorite),
-            BoxSetCount = GetCount(BaseItemKind.BoxSet, user, isFavorite),
-            BookCount = GetCount(BaseItemKind.Book, user, isFavorite)
+            Recursive = true,
+            IsVirtualItem = false,
+            IsFavorite = isFavorite,
+            DtoOptions = new DtoOptions(false)
+            {
+                EnableImages = false
+            }
         };
 
-        return counts;
+        return _libraryManager.GetItemCounts(query);
     }
 
     /// <summary>
@@ -937,24 +936,6 @@ public class LibraryController : BaseJellyfinApiController
         return result;
     }
 
-    private int GetCount(BaseItemKind itemKind, User? user, bool? isFavorite)
-    {
-        var query = new InternalItemsQuery(user)
-        {
-            IncludeItemTypes = new[] { itemKind },
-            Limit = 0,
-            Recursive = true,
-            IsVirtualItem = false,
-            IsFavorite = isFavorite,
-            DtoOptions = new DtoOptions(false)
-            {
-                EnableImages = false
-            }
-        };
-
-        return _libraryManager.GetItemsResult(query).TotalRecordCount;
-    }
-
     private BaseItem? TranslateParentItem(BaseItem item, User user)
     {
         return item.GetParent() is AggregateFolder
diff --git a/Jellyfin.Api/Controllers/VideosController.cs b/Jellyfin.Api/Controllers/VideosController.cs
index ccf8e90632..2237e36b5f 100644
--- a/Jellyfin.Api/Controllers/VideosController.cs
+++ b/Jellyfin.Api/Controllers/VideosController.cs
@@ -157,7 +157,7 @@ public class VideosController : BaseJellyfinApiController
             return NotFound();
         }
 
-        foreach (var link in item.GetLinkedAlternateVersions())
+        foreach (var link in _libraryManager.GetLinkedAlternateVersions(item))
         {
             link.SetPrimaryVersionId(null);
             link.LinkedAlternateVersions = Array.Empty<LinkedChild>();
@@ -222,18 +222,18 @@ public class VideosController : BaseJellyfinApiController
 
             await item.UpdateToRepositoryAsync(ItemUpdateType.MetadataEdit, CancellationToken.None).ConfigureAwait(false);
 
-            if (!alternateVersionsOfPrimary.Any(i => string.Equals(i.Path, item.Path, StringComparison.OrdinalIgnoreCase)))
+            if (!alternateVersionsOfPrimary.Any(i => i.ItemId.HasValue && i.ItemId.Value.Equals(item.Id)))
             {
                 alternateVersionsOfPrimary.Add(new LinkedChild
                 {
-                    Path = item.Path,
-                    ItemId = item.Id
+                    ItemId = item.Id,
+                    Type = LinkedChildType.LinkedAlternateVersion
                 });
             }
 
             foreach (var linkedItem in item.LinkedAlternateVersions)
             {
-                if (!alternateVersionsOfPrimary.Any(i => string.Equals(i.Path, linkedItem.Path, StringComparison.OrdinalIgnoreCase)))
+                if (linkedItem.ItemId.HasValue && !alternateVersionsOfPrimary.Any(i => i.ItemId.HasValue && i.ItemId.Value.Equals(linkedItem.ItemId.Value)))
                 {
                     alternateVersionsOfPrimary.Add(linkedItem);
                 }
diff --git a/Jellyfin.Server.Implementations/Item/BaseItemRepository.cs b/Jellyfin.Server.Implementations/Item/BaseItemRepository.cs
index 110b6b5faf..bfaaa4b24a 100644
--- a/Jellyfin.Server.Implementations/Item/BaseItemRepository.cs
+++ b/Jellyfin.Server.Implementations/Item/BaseItemRepository.cs
@@ -1,6 +1,7 @@
 #pragma warning disable RS0030 // Do not use banned APIs
 // Do not enforce that because EFCore cannot deal with cultures well.
 #pragma warning disable CA1304 // Specify CultureInfo
+#pragma warning disable CA1309 // Use ordinal string comparison
 #pragma warning disable CA1311 // Specify a culture or use an invariant version
 #pragma warning disable CA1862 // Use the 'StringComparison' method overloads to perform case-insensitive string comparisons
 
@@ -19,6 +20,7 @@ using Jellyfin.Data.Enums;
 using Jellyfin.Database.Implementations;
 using Jellyfin.Database.Implementations.Entities;
 using Jellyfin.Database.Implementations.Enums;
+using Jellyfin.Database.Implementations.MatchCriteria;
 using Jellyfin.Extensions;
 using Jellyfin.Extensions.Json;
 using Jellyfin.Server.Implementations.Extensions;
@@ -31,6 +33,7 @@ using MediaBrowser.Controller.Entities.Audio;
 using MediaBrowser.Controller.Entities.TV;
 using MediaBrowser.Controller.LiveTv;
 using MediaBrowser.Controller.Persistence;
+using MediaBrowser.Controller.Playlists;
 using MediaBrowser.Model.Dto;
 using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.LiveTv;
@@ -39,6 +42,8 @@ using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using BaseItemDto = MediaBrowser.Controller.Entities.BaseItem;
 using BaseItemEntity = Jellyfin.Database.Implementations.Entities.BaseItemEntity;
+using DbLinkedChildType = Jellyfin.Database.Implementations.Entities.LinkedChildType;
+using LinkedChildType = MediaBrowser.Controller.Entities.LinkedChildType;
 
 namespace Jellyfin.Server.Implementations.Item;
 
@@ -69,6 +74,7 @@ public sealed class BaseItemRepository
     private readonly IItemTypeLookup _itemTypeLookup;
     private readonly IServerConfigurationManager _serverConfigurationManager;
     private readonly ILogger<BaseItemRepository> _logger;
+    private readonly IDescendantQueryProvider _descendantQueryProvider;
 
     private static readonly IReadOnlyList<ItemValueType> _getAllArtistsValueTypes = [ItemValueType.Artist, ItemValueType.AlbumArtist];
     private static readonly IReadOnlyList<ItemValueType> _getArtistValueTypes = [ItemValueType.Artist];
@@ -77,6 +83,10 @@ public sealed class BaseItemRepository
     private static readonly IReadOnlyList<ItemValueType> _getGenreValueTypes = [ItemValueType.Genre];
     private static readonly IReadOnlyList<char> SearchWildcardTerms = ['%', '_', '[', ']', '^'];
 
+    private static readonly string ImdbProviderName = MetadataProvider.Imdb.ToString().ToLowerInvariant();
+    private static readonly string TmdbProviderName = MetadataProvider.Tmdb.ToString().ToLowerInvariant();
+    private static readonly string TvdbProviderName = MetadataProvider.Tvdb.ToString().ToLowerInvariant();
+
     /// <summary>
     /// Initializes a new instance of the <see cref="BaseItemRepository"/> class.
     /// </summary>
@@ -85,18 +95,21 @@ public sealed class BaseItemRepository
     /// <param name="itemTypeLookup">The static type lookup.</param>
     /// <param name="serverConfigurationManager">The server Configuration manager.</param>
     /// <param name="logger">System logger.</param>
+    /// <param name="databaseProvider">The database provider for database-specific operations.</param>
     public BaseItemRepository(
         IDbContextFactory<JellyfinDbContext> dbProvider,
         IServerApplicationHost appHost,
         IItemTypeLookup itemTypeLookup,
         IServerConfigurationManager serverConfigurationManager,
-        ILogger<BaseItemRepository> logger)
+        ILogger<BaseItemRepository> logger,
+        IJellyfinDatabaseProvider databaseProvider)
     {
         _dbProvider = dbProvider;
         _appHost = appHost;
         _itemTypeLookup = itemTypeLookup;
         _serverConfigurationManager = serverConfigurationManager;
         _logger = logger;
+        _descendantQueryProvider = databaseProvider.DescendantQueryProvider;
     }
 
     /// <inheritdoc />
@@ -112,7 +125,23 @@ public sealed class BaseItemRepository
 
         var date = (DateTime?)DateTime.UtcNow;
 
-        var relatedItems = ids.SelectMany(f => TraverseHirachyDown(f, context)).ToArray();
+        var descendantIds = ids.SelectMany(f => _descendantQueryProvider.GetAllDescendantIds(context, f)).ToHashSet();
+        foreach (var id in ids)
+        {
+            descendantIds.Add(id);
+        }
+
+        var extraIds = context.BaseItems
+            .Where(e => e.OwnerId.HasValue && descendantIds.Contains(e.OwnerId.Value))
+            .Select(e => e.Id)
+            .ToArray();
+
+        foreach (var extraId in extraIds)
+        {
+            descendantIds.Add(extraId);
+        }
+
+        var relatedItems = descendantIds.ToArray();
 
         // Remove any UserData entries for the placeholder item that would conflict with the UserData
         // being detached from the item being deleted. This is necessary because, during an update,
@@ -140,12 +169,14 @@ public sealed class BaseItemRepository
         context.BaseItemMetadataFields.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
         context.BaseItemProviders.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
         context.BaseItemTrailerTypes.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
-        context.BaseItems.WhereOneOrMany(relatedItems, e => e.Id).ExecuteDelete();
         context.Chapters.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
         context.CustomItemDisplayPreferences.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
         context.ItemDisplayPreferences.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
         context.ItemValues.Where(e => e.BaseItemsMap!.Count == 0).ExecuteDelete();
         context.ItemValuesMap.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
+        context.LinkedChildren.WhereOneOrMany(relatedItems, e => e.ParentId).ExecuteDelete();
+        context.LinkedChildren.WhereOneOrMany(relatedItems, e => e.ChildId).ExecuteDelete();
+        context.BaseItems.WhereOneOrMany(relatedItems, e => e.Id).ExecuteDelete();
         context.KeyframeData.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
         context.MediaSegments.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
         context.MediaStreamInfos.WhereOneOrMany(relatedItems, e => e.ItemId).ExecuteDelete();
@@ -250,7 +281,7 @@ public sealed class BaseItemRepository
     public QueryResult<BaseItemDto> GetItems(InternalItemsQuery filter)
     {
         ArgumentNullException.ThrowIfNull(filter);
-        if (!filter.EnableTotalRecordCount || ((filter.Limit ?? 0) == 0 && (filter.StartIndex ?? 0) == 0))
+        if (!filter.EnableTotalRecordCount || (!filter.Limit.HasValue && (filter.StartIndex ?? 0) == 0))
         {
             var returnList = GetItemList(filter);
             return new QueryResult<BaseItemDto>(
@@ -301,47 +332,276 @@ public sealed class BaseItemRepository
     }
 
     /// <inheritdoc/>
-    public IReadOnlyList<BaseItem> GetLatestItemList(InternalItemsQuery filter, CollectionType collectionType)
+    public IReadOnlyList<BaseItemDto> GetLatestItemList(InternalItemsQuery filter, CollectionType collectionType)
     {
         ArgumentNullException.ThrowIfNull(filter);
         PrepareFilterQuery(filter);
 
-        // Early exit if collection type is not tvshows or music
-        if (collectionType != CollectionType.tvshows && collectionType != CollectionType.music)
+        // Early exit if collection type is not supported
+        if (collectionType is not CollectionType.movies and not CollectionType.tvshows and not CollectionType.music)
         {
-            return Array.Empty<BaseItem>();
+            return [];
         }
 
+        var limit = filter.Limit ?? 50;
         using var context = _dbProvider.CreateDbContext();
 
-        // Subquery to group by SeriesNames/Album and get the max Date Created for each group.
-        var subquery = PrepareItemQuery(context, filter);
-        subquery = TranslateQuery(subquery, context, filter);
-        var subqueryGrouped = subquery.GroupBy(g => collectionType == CollectionType.tvshows ? g.SeriesName : g.Album)
-            .Select(g => new
+        var baseQuery = PrepareItemQuery(context, filter);
+        baseQuery = TranslateQuery(baseQuery, context, filter);
+
+        if (collectionType == CollectionType.tvshows)
+        {
+            return GetLatestTvShowItems(context, baseQuery, filter, limit);
+        }
+
+        // Determine the grouping key selector based on collection type
+        // Movies: PresentationUniqueKey (groups alternate versions like 4K/1080p)
+        // Music: Album
+        Func<BaseItemEntity, string?> groupKeySelector = collectionType switch
+        {
+            CollectionType.movies => e => e.PresentationUniqueKey,
+            _ => e => e.Album
+        };
+
+        // EF Core requires compile-time expressions, so we use conditional queries
+        var topGroupKeys = collectionType switch
+        {
+            CollectionType.movies => baseQuery
+                .Where(e => e.PresentationUniqueKey != null)
+                .GroupBy(e => e.PresentationUniqueKey)
+                .Select(g => new { GroupKey = g.Key!, MaxDate = g.Max(e => e.DateCreated) })
+                .OrderByDescending(g => g.MaxDate)
+                .Take(limit)
+                .Select(g => g.GroupKey)
+                .ToList(),
+            _ => baseQuery
+                .Where(e => e.Album != null)
+                .GroupBy(e => e.Album)
+                .Select(g => new { GroupKey = g.Key!, MaxDate = g.Max(e => e.DateCreated) })
+                .OrderByDescending(g => g.MaxDate)
+                .Take(limit)
+                .Select(g => g.GroupKey)
+                .ToList()
+        };
+
+        if (topGroupKeys.Count == 0)
+        {
+            return [];
+        }
+
+        var itemsQuery = collectionType switch
+        {
+            CollectionType.movies => baseQuery.Where(e => e.PresentationUniqueKey != null && topGroupKeys.Contains(e.PresentationUniqueKey)),
+            _ => baseQuery.Where(e => e.Album != null && topGroupKeys.Contains(e.Album))
+        };
+
+        itemsQuery = itemsQuery.OrderByDescending(e => e.DateCreated).ThenByDescending(e => e.Id);
+        itemsQuery = ApplyNavigations(itemsQuery, filter).AsSingleQuery();
+
+        var allItems = itemsQuery.ToList();
+
+        var latestItems = allItems
+            .GroupBy(groupKeySelector)
+            .Select(g => g.First())
+            .OrderByDescending(e => e.DateCreated)
+            .ThenByDescending(e => e.Id)
+            .ToList();
+
+        return latestItems
+            .Select(w => DeserializeBaseItem(w, filter.SkipDeserialization))
+            .Where(dto => dto is not null)
+            .ToArray()!;
+    }
+
+    /// <summary>
+    /// Gets the latest TV show items with smart Season/Series container selection.
+    /// </summary>
+    /// <remarks>
+    /// If multiple episodes were recently added to a single season, returns the Season.
+    /// If episodes span multiple seasons, returns the Series.
+    /// If only a single episode was added, returns the Episode.
+    /// </remarks>
+    private IReadOnlyList<BaseItemDto> GetLatestTvShowItems(JellyfinDbContext context, IQueryable<BaseItemEntity> baseQuery, InternalItemsQuery filter, int limit)
+    {
+        const int WindowDays = 7;
+        const int MaxWindowDays = 84;
+        const double RecentAdditionWindowHours = 24.0;
+
+        var now = DateTime.UtcNow;
+
+        List<string> topSeriesNames = [];
+        for (int days = WindowDays; days <= MaxWindowDays && topSeriesNames.Count < limit; days += WindowDays)
+        {
+            var cutoff = now.AddDays(-days);
+            topSeriesNames = baseQuery
+                .Where(e => e.SeriesName != null && e.DateCreated >= cutoff)
+                .GroupBy(e => e.SeriesName)
+                .OrderByDescending(g => g.Max(e => e.DateCreated))
+                .Take(limit)
+                .Select(g => g.Key!)
+                .ToList();
+        }
+
+        // Fallback without date filter if needed
+        if (topSeriesNames.Count < limit)
+        {
+            topSeriesNames = baseQuery
+                .Where(e => e.SeriesName != null)
+                .GroupBy(e => e.SeriesName)
+                .OrderByDescending(g => g.Max(e => e.DateCreated))
+                .Take(limit)
+                .Select(g => g.Key!)
+                .ToList();
+        }
+
+        if (topSeriesNames.Count == 0)
+        {
+            return [];
+        }
+
+        // Get all episodes from identified series with navigations
+        var allEpisodes = ApplyNavigations(
+                baseQuery
+                    .Where(e => e.SeriesName != null && topSeriesNames.Contains(e.SeriesName))
+                    .OrderByDescending(e => e.DateCreated)
+                    .ThenByDescending(e => e.Id),
+                filter)
+            .AsSingleQuery()
+            .ToList();
+
+        var allSeasonIds = new HashSet<Guid>();
+        var allSeriesIds = new HashSet<Guid>();
+        var analysisData = new List<(
+            List<BaseItemEntity> RecentEpisodes,
+            List<Guid> SeasonIds,
+            DateTime MaxDate,
+            BaseItemEntity MostRecentEpisode)>();
+
+        foreach (var group in allEpisodes.GroupBy(e => e.SeriesName))
+        {
+            var episodes = group.ToList();
+            var mostRecentDate = episodes[0].DateCreated ?? DateTime.MinValue;
+            var recentCutoff = mostRecentDate.AddHours(-RecentAdditionWindowHours);
+
+            var recentEpisodes = new List<BaseItemEntity>();
+            var seasonIdSet = new HashSet<Guid>();
+
+            foreach (var ep in episodes)
             {
-                Key = g.Key,
-                MaxDateCreated = g.Max(a => a.DateCreated)
-            })
-            .OrderByDescending(g => g.MaxDateCreated)
-            .Select(g => g);
+                if (ep.DateCreated >= recentCutoff)
+                {
+                    recentEpisodes.Add(ep);
+                    if (ep.SeasonId.HasValue)
+                    {
+                        seasonIdSet.Add(ep.SeasonId.Value);
+                    }
+                }
+            }
+
+            var seasonIds = seasonIdSet.ToList();
+            analysisData.Add((recentEpisodes, seasonIds, mostRecentDate, episodes[0]));
+
+            foreach (var sid in seasonIds)
+            {
+                allSeasonIds.Add(sid);
+            }
 
-        if (filter.Limit.HasValue && filter.Limit.Value > 0)
+            if (recentEpisodes.Count > 0 && recentEpisodes[0].SeriesId.HasValue)
+            {
+                allSeriesIds.Add(recentEpisodes[0].SeriesId!.Value);
+            }
+        }
+
+        var episodeType = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Episode];
+        var seasonType = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Season];
+        var seasonEpisodeCounts = allSeasonIds.Count > 0
+            ? context.BaseItems
+                .AsNoTracking()
+                .Where(e => e.SeasonId.HasValue && allSeasonIds.Contains(e.SeasonId.Value) && e.Type == episodeType)
+                .GroupBy(e => e.SeasonId!.Value)
+                .Select(g => new { SeasonId = g.Key, Count = g.Count() })
+                .ToDictionary(x => x.SeasonId, x => x.Count)
+            : [];
+
+        var seriesSeasonCounts = allSeriesIds.Count > 0
+            ? context.BaseItems
+                .AsNoTracking()
+                .Where(e => e.SeriesId.HasValue && allSeriesIds.Contains(e.SeriesId.Value) && e.Type == seasonType)
+                .GroupBy(e => e.SeriesId!.Value)
+                .Select(g => new { SeriesId = g.Key, Count = g.Count() })
+                .ToDictionary(x => x.SeriesId, x => x.Count)
+            : [];
+
+        var entitiesToFetch = new HashSet<Guid>();
+        var seriesResults = new List<(Guid? SeasonId, Guid? SeriesId, DateTime MaxDate, BaseItemEntity MostRecentEpisode)>(analysisData.Count);
+        foreach (var (recentEpisodes, seasonIds, maxDate, mostRecentEpisode) in analysisData)
         {
-            subqueryGrouped = subqueryGrouped.Take(filter.Limit.Value);
+            Guid? seasonId = null;
+            Guid? seriesId = null;
+
+            if (seasonIds.Count == 1)
+            {
+                var sid = seasonIds[0];
+                var totalEpisodes = seasonEpisodeCounts.GetValueOrDefault(sid, 0);
+                var episodeSeriesId = recentEpisodes.Count > 0 ? recentEpisodes[0].SeriesId : null;
+                var totalSeasonsInSeries = episodeSeriesId.HasValue
+                    ? seriesSeasonCounts.GetValueOrDefault(episodeSeriesId.Value, 1)
+                    : 1;
+
+                var hasMultipleOrAllEpisodes = recentEpisodes.Count > 1 || recentEpisodes.Count == totalEpisodes;
+                if (totalSeasonsInSeries > 1 && hasMultipleOrAllEpisodes)
+                {
+                    seasonId = sid;
+                    entitiesToFetch.Add(sid);
+                }
+                else if (hasMultipleOrAllEpisodes && episodeSeriesId.HasValue)
+                {
+                    seriesId = episodeSeriesId;
+                    entitiesToFetch.Add(episodeSeriesId.Value);
+                }
+            }
+            else if (seasonIds.Count > 1 && recentEpisodes.Count > 0 && recentEpisodes[0].SeriesId.HasValue)
+            {
+                seriesId = recentEpisodes[0].SeriesId;
+                entitiesToFetch.Add(seriesId!.Value);
+            }
+
+            seriesResults.Add((seasonId, seriesId, maxDate, mostRecentEpisode));
         }
 
-        filter.Limit = null;
+        var entities = entitiesToFetch.Count > 0
+            ? ApplyNavigations(
+                    context.BaseItems.AsNoTracking().Where(e => entitiesToFetch.Contains(e.Id)),
+                    filter)
+                .AsSingleQuery()
+                .ToDictionary(e => e.Id)
+            : [];
 
-        var mainquery = PrepareItemQuery(context, filter);
-        mainquery = TranslateQuery(mainquery, context, filter);
-        mainquery = mainquery.Where(g => g.DateCreated >= subqueryGrouped.Min(s => s.MaxDateCreated));
-        mainquery = ApplyGroupingFilter(context, mainquery, filter);
-        mainquery = ApplyQueryPaging(mainquery, filter);
+        var results = new List<(BaseItemEntity Entity, DateTime MaxDate)>(seriesResults.Count);
+        foreach (var (seasonId, seriesId, maxDate, mostRecentEpisode) in seriesResults)
+        {
+            if (seasonId.HasValue && entities.TryGetValue(seasonId.Value, out var seasonEntity))
+            {
+                results.Add((seasonEntity, maxDate));
+                continue;
+            }
 
-        mainquery = ApplyNavigations(mainquery, filter);
+            if (seriesId.HasValue && entities.TryGetValue(seriesId.Value, out var seriesEntity))
+            {
+                results.Add((seriesEntity, maxDate));
+                continue;
+            }
 
-        return mainquery.AsEnumerable().Where(e => e is not null).Select(w => DeserializeBaseItem(w, filter.SkipDeserialization)).Where(dto => dto is not null).ToArray()!;
+            results.Add((mostRecentEpisode, maxDate));
+        }
+
+        return results
+            .OrderByDescending(r => r.MaxDate)
+            .ThenByDescending(r => r.Entity.Id)
+            .Take(limit)
+            .Select(r => DeserializeBaseItem(r.Entity, filter.SkipDeserialization))
+            .Where(dto => dto is not null)
+            .ToArray()!;
     }
 
     /// <inheritdoc />
@@ -367,7 +627,7 @@ public sealed class BaseItemRepository
             .OrderByDescending(g => g.LastPlayedDate)
             .Select(g => g.Key!);
 
-        if (filter.Limit.HasValue && filter.Limit.Value > 0)
+        if (filter.Limit.HasValue)
         {
             query = query.Take(filter.Limit.Value);
         }
@@ -375,6 +635,277 @@ public sealed class BaseItemRepository
         return query.ToArray();
     }
 
+    /// <inheritdoc />
+    public IReadOnlyDictionary<string, NextUpEpisodeBatchResult> GetNextUpEpisodesBatch(
+        InternalItemsQuery filter,
+        IReadOnlyList<string> seriesKeys,
+        bool includeSpecials,
+        bool includeWatchedForRewatching)
+    {
+        ArgumentNullException.ThrowIfNull(filter);
+        ArgumentNullException.ThrowIfNull(filter.User);
+
+        if (seriesKeys.Count == 0)
+        {
+            return new Dictionary<string, NextUpEpisodeBatchResult>();
+        }
+
+        PrepareFilterQuery(filter);
+        using var context = _dbProvider.CreateDbContext();
+
+        var userId = filter.User.Id;
+        var episodeTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Episode];
+
+        // Get the last watched episode ID per series (highest season/episode that is played)
+        var lastWatchedInfo = context.BaseItems
+            .AsNoTracking()
+            .Where(e => e.Type == episodeTypeName)
+            .Where(e => e.SeriesPresentationUniqueKey != null && seriesKeys.Contains(e.SeriesPresentationUniqueKey))
+            .Where(e => e.ParentIndexNumber != 0)
+            .Where(e => e.UserData!.Any(ud => ud.UserId == userId && ud.Played))
+            .GroupBy(e => e.SeriesPresentationUniqueKey)
+            .Select(g => new
+            {
+                SeriesKey = g.Key!,
+                LastWatchedId = g.OrderByDescending(e => e.ParentIndexNumber)
+                                 .ThenByDescending(e => e.IndexNumber)
+                                 .Select(e => e.Id)
+                                 .FirstOrDefault()
+            })
+            .ToDictionary(x => x.SeriesKey, x => x.LastWatchedId);
+
+        Dictionary<string, Guid> lastWatchedByDateInfo = new();
+        if (includeWatchedForRewatching)
+        {
+            lastWatchedByDateInfo = context.BaseItems
+                .AsNoTracking()
+                .Where(e => e.Type == episodeTypeName)
+                .Where(e => e.SeriesPresentationUniqueKey != null && seriesKeys.Contains(e.SeriesPresentationUniqueKey))
+                .Where(e => e.ParentIndexNumber != 0)
+                .Where(e => e.UserData!.Any(ud => ud.UserId == userId && ud.Played))
+                .SelectMany(e => e.UserData!.Where(ud => ud.UserId == userId && ud.Played)
+                    .Select(ud => new { Episode = e, ud.LastPlayedDate }))
+                .GroupBy(x => x.Episode.SeriesPresentationUniqueKey)
+                .Select(g => new
+                {
+                    SeriesKey = g.Key!,
+                    LastWatchedId = g.OrderByDescending(x => x.LastPlayedDate)
+                                     .Select(x => x.Episode.Id)
+                                     .FirstOrDefault()
+                })
+                .ToDictionary(x => x.SeriesKey, x => x.LastWatchedId);
+        }
+
+        var allLastWatchedIds = lastWatchedInfo.Values
+            .Concat(lastWatchedByDateInfo.Values)
+            .Where(id => id != Guid.Empty)
+            .Distinct()
+            .ToList();
+        var lastWatchedEpisodes = new Dictionary<Guid, BaseItemEntity>();
+        if (allLastWatchedIds.Count > 0)
+        {
+            var lwQuery = context.BaseItems.AsNoTracking().Where(e => allLastWatchedIds.Contains(e.Id));
+            lwQuery = ApplyNavigations(lwQuery, filter).AsSingleQuery();
+            lastWatchedEpisodes = lwQuery.ToDictionary(e => e.Id);
+        }
+
+        var allNextUnwatchedCandidates = context.BaseItems
+            .AsNoTracking()
+            .Where(e => e.Type == episodeTypeName)
+            .Where(e => e.SeriesPresentationUniqueKey != null && seriesKeys.Contains(e.SeriesPresentationUniqueKey))
+            .Where(e => e.ParentIndexNumber != 0)
+            .Where(e => !e.IsVirtualItem)
+            .Where(e => !e.UserData!.Any(ud => ud.UserId == userId && ud.Played))
+            .Select(e => new
+            {
+                e.Id,
+                e.SeriesPresentationUniqueKey,
+                e.ParentIndexNumber,
+                EpisodeNumber = e.IndexNumber
+            })
+            .ToList();
+
+        List<(Guid Id, string? SeriesKey, int? Season, int? Episode)> allNextPlayedCandidates = new();
+        if (includeWatchedForRewatching)
+        {
+            allNextPlayedCandidates = context.BaseItems
+                .AsNoTracking()
+                .Where(e => e.Type == episodeTypeName)
+                .Where(e => e.SeriesPresentationUniqueKey != null && seriesKeys.Contains(e.SeriesPresentationUniqueKey))
+                .Where(e => e.ParentIndexNumber != 0)
+                .Where(e => !e.IsVirtualItem)
+                .Where(e => e.UserData!.Any(ud => ud.UserId == userId && ud.Played))
+                .Select(e => new
+                {
+                    e.Id,
+                    e.SeriesPresentationUniqueKey,
+                    e.ParentIndexNumber,
+                    EpisodeNumber = e.IndexNumber
+                })
+                .AsEnumerable()
+                .Select(e => (e.Id, e.SeriesPresentationUniqueKey, e.ParentIndexNumber, e.EpisodeNumber))
+                .ToList();
+        }
+
+        Dictionary<string, List<BaseItemEntity>> specialsBySeriesKey = new();
+        if (includeSpecials)
+        {
+            var allSpecials = context.BaseItems
+                .AsNoTracking()
+                .Where(e => e.Type == episodeTypeName)
+                .Where(e => e.SeriesPresentationUniqueKey != null && seriesKeys.Contains(e.SeriesPresentationUniqueKey))
+                .Where(e => e.ParentIndexNumber == 0)
+                .Where(e => !e.IsVirtualItem)
+                .ToList();
+
+            var specialIds = allSpecials.Select(s => s.Id).ToList();
+            if (specialIds.Count > 0)
+            {
+                var specialsWithNav = context.BaseItems.AsNoTracking().Where(e => specialIds.Contains(e.Id));
+                specialsWithNav = ApplyNavigations(specialsWithNav, filter).AsSingleQuery();
+                var specialsDict = specialsWithNav.ToDictionary(e => e.Id);
+
+                foreach (var special in allSpecials)
+                {
+                    var key = special.SeriesPresentationUniqueKey!;
+                    if (!specialsBySeriesKey.TryGetValue(key, out var list))
+                    {
+                        list = new List<BaseItemEntity>();
+                        specialsBySeriesKey[key] = list;
+                    }
+
+                    if (specialsDict.TryGetValue(special.Id, out var specialWithNav))
+                    {
+                        list.Add(specialWithNav);
+                    }
+                }
+            }
+        }
+
+        var nextEpisodeIds = new HashSet<Guid>();
+        var seriesNextIdMap = new Dictionary<string, Guid>();
+        var seriesNextPlayedIdMap = new Dictionary<string, Guid>();
+
+        foreach (var seriesKey in seriesKeys)
+        {
+            var candidates = allNextUnwatchedCandidates
+                .Where(c => c.SeriesPresentationUniqueKey == seriesKey);
+
+            if (lastWatchedInfo.TryGetValue(seriesKey, out var lwId) && lwId != Guid.Empty)
+            {
+                var lastWatchedEntity = lastWatchedEpisodes.GetValueOrDefault(lwId);
+                if (lastWatchedEntity is not null)
+                {
+                    var season = lastWatchedEntity.ParentIndexNumber;
+                    var episode = lastWatchedEntity.IndexNumber;
+                    if (season.HasValue && episode.HasValue)
+                    {
+                        candidates = candidates.Where(c =>
+                            c.ParentIndexNumber > season ||
+                            (c.ParentIndexNumber == season && c.EpisodeNumber > episode));
+                    }
+                }
+            }
+
+            var nextCandidate = candidates
+                .OrderBy(c => c.ParentIndexNumber)
+                .ThenBy(c => c.EpisodeNumber)
+                .FirstOrDefault();
+
+            if (nextCandidate is not null && nextCandidate.Id != Guid.Empty)
+            {
+                nextEpisodeIds.Add(nextCandidate.Id);
+                seriesNextIdMap[seriesKey] = nextCandidate.Id;
+            }
+
+            if (includeWatchedForRewatching && lastWatchedByDateInfo.TryGetValue(seriesKey, out var lastByDateId))
+            {
+                var lastByDateEntity = lastWatchedEpisodes.GetValueOrDefault(lastByDateId);
+                if (lastByDateEntity is not null)
+                {
+                    var lastSeason = lastByDateEntity.ParentIndexNumber;
+                    var lastEp = lastByDateEntity.IndexNumber;
+
+                    var playedCandidates = allNextPlayedCandidates
+                        .Where(c => c.SeriesKey == seriesKey);
+
+                    if (lastSeason.HasValue && lastEp.HasValue)
+                    {
+                        playedCandidates = playedCandidates.Where(c =>
+                            c.Season > lastSeason ||
+                            (c.Season == lastSeason && c.Episode > lastEp));
+                    }
+
+                    var nextPlayedCandidate = playedCandidates
+                        .OrderBy(c => c.Season)
+                        .ThenBy(c => c.Episode)
+                        .FirstOrDefault();
+
+                    if (nextPlayedCandidate.Id != Guid.Empty)
+                    {
+                        nextEpisodeIds.Add(nextPlayedCandidate.Id);
+                        seriesNextPlayedIdMap[seriesKey] = nextPlayedCandidate.Id;
+                    }
+                }
+            }
+        }
+
+        var nextEpisodes = new Dictionary<Guid, BaseItemEntity>();
+        if (nextEpisodeIds.Count > 0)
+        {
+            var nextQuery = context.BaseItems.AsNoTracking().Where(e => nextEpisodeIds.Contains(e.Id));
+            nextQuery = ApplyNavigations(nextQuery, filter).AsSingleQuery();
+            nextEpisodes = nextQuery.ToDictionary(e => e.Id);
+        }
+
+        var result = new Dictionary<string, NextUpEpisodeBatchResult>();
+        foreach (var seriesKey in seriesKeys)
+        {
+            var batchResult = new NextUpEpisodeBatchResult();
+
+            if (lastWatchedInfo.TryGetValue(seriesKey, out var lwId) && lwId != Guid.Empty)
+            {
+                if (lastWatchedEpisodes.TryGetValue(lwId, out var entity))
+                {
+                    batchResult.LastWatched = DeserializeBaseItem(entity, filter.SkipDeserialization);
+                }
+            }
+
+            if (seriesNextIdMap.TryGetValue(seriesKey, out var nextId) && nextEpisodes.TryGetValue(nextId, out var nextEntity))
+            {
+                batchResult.NextUp = DeserializeBaseItem(nextEntity, filter.SkipDeserialization);
+            }
+
+            if (includeSpecials && specialsBySeriesKey.TryGetValue(seriesKey, out var specials))
+            {
+                batchResult.Specials = specials.Select(s => DeserializeBaseItem(s, filter.SkipDeserialization)!).ToList();
+            }
+            else
+            {
+                batchResult.Specials = Array.Empty<BaseItemDto>();
+            }
+
+            if (includeWatchedForRewatching)
+            {
+                if (lastWatchedByDateInfo.TryGetValue(seriesKey, out var lastByDateId) &&
+                    lastWatchedEpisodes.TryGetValue(lastByDateId, out var lastByDateEntity))
+                {
+                    batchResult.LastWatchedForRewatching = DeserializeBaseItem(lastByDateEntity, filter.SkipDeserialization);
+                }
+
+                if (seriesNextPlayedIdMap.TryGetValue(seriesKey, out var nextPlayedId) &&
+                    nextEpisodes.TryGetValue(nextPlayedId, out var nextPlayedEntity))
+                {
+                    batchResult.NextPlayedForRewatching = DeserializeBaseItem(nextPlayedEntity, filter.SkipDeserialization);
+                }
+            }
+
+            result[seriesKey] = batchResult;
+        }
+
+        return result;
+    }
+
     private IQueryable<BaseItemEntity> ApplyGroupingFilter(JellyfinDbContext context, IQueryable<BaseItemEntity> dbQuery, InternalItemsQuery filter)
     {
         // This whole block is needed to filter duplicate entries on request
@@ -435,19 +966,44 @@ public sealed class BaseItemRepository
             dbQuery = dbQuery.Include(e => e.Images);
         }
 
+        // Only include LinkedChildEntities for container types and videos that use them
+        // (BoxSet, Playlist, CollectionFolder for manual linking; Video, Movie for alternate versions)
+        var linkedChildTypes = new[]
+        {
+            BaseItemKind.BoxSet,
+            BaseItemKind.Playlist,
+            BaseItemKind.CollectionFolder,
+            BaseItemKind.Video,
+            BaseItemKind.Movie
+        };
+        if (filter.IncludeItemTypes.Length == 0 || filter.IncludeItemTypes.Any(linkedChildTypes.Contains))
+        {
+            dbQuery = dbQuery.Include(e => e.LinkedChildEntities);
+        }
+
+        if (filter.IncludeExtras)
+        {
+            dbQuery = dbQuery.Include(e => e.Extras);
+        }
+
         return dbQuery;
     }
 
     private IQueryable<BaseItemEntity> ApplyQueryPaging(IQueryable<BaseItemEntity> dbQuery, InternalItemsQuery filter)
     {
-        if (filter.StartIndex.HasValue && filter.StartIndex.Value > 0)
+        if (filter.Limit.HasValue || filter.StartIndex.HasValue)
         {
-            dbQuery = dbQuery.Skip(filter.StartIndex.Value);
-        }
+            var offset = filter.StartIndex ?? 0;
 
-        if (filter.Limit.HasValue && filter.Limit.Value > 0)
-        {
-            dbQuery = dbQuery.Take(filter.Limit.Value);
+            if (offset > 0)
+            {
+                dbQuery = dbQuery.Skip(offset);
+            }
+
+            if (filter.Limit.HasValue)
+            {
+                dbQuery = dbQuery.Take(filter.Limit.Value);
+            }
         }
 
         return dbQuery;
@@ -499,7 +1055,10 @@ public sealed class BaseItemRepository
             .ToArray();
 
         var lookup = _itemTypeLookup.BaseItemKindNames;
-        var result = new ItemCounts();
+        var result = new ItemCounts
+        {
+            ItemCount = counts.Sum(c => c.Count)
+        };
         foreach (var count in counts)
         {
             if (string.Equals(count.Key, lookup[BaseItemKind.MusicAlbum], StringComparison.Ordinal))
@@ -538,6 +1097,14 @@ public sealed class BaseItemRepository
             {
                 result.TrailerCount = count.Count;
             }
+            else if (string.Equals(count.Key, lookup[BaseItemKind.BoxSet], StringComparison.Ordinal))
+            {
+                result.BoxSetCount = count.Count;
+            }
+            else if (string.Equals(count.Key, lookup[BaseItemKind.Book], StringComparison.Ordinal))
+            {
+                result.BookCount = count.Count;
+            }
         }
 
         return result;
@@ -561,8 +1128,36 @@ public sealed class BaseItemRepository
             .FirstOrDefault(t => t is not null));
     }
 
+    /// <summary>
+    /// Saves image information for an item.
+    /// </summary>
+    /// <param name="item">The item DTO containing image info.</param>
+    public void SaveImages(BaseItemDto item)
+    {
+        ArgumentNullException.ThrowIfNull(item);
+
+        var images = item.ImageInfos.Select(e => Map(item.Id, e));
+        using var context = _dbProvider.CreateDbContext();
+
+        if (!context.BaseItems.Any(bi => bi.Id == item.Id))
+        {
+            _logger.LogWarning("Unable to save ImageInfo for non existing BaseItem");
+            return;
+        }
+
+        context.BaseItemImageInfos.Where(e => e.ItemId == item.Id).ExecuteDelete();
+        context.BaseItemImageInfos.AddRange(images);
+        context.SaveChanges();
+    }
+
     /// <inheritdoc  />
-    public async Task SaveImagesAsync(BaseItemDto item, CancellationToken cancellationToken = default)
+    public void SaveItems(IReadOnlyList<BaseItemDto> items, CancellationToken cancellationToken)
+    {
+        UpdateOrInsertItems(items, cancellationToken);
+    }
+
+    /// <inheritdoc />
+    public async Task SaveImagesAsync(BaseItem item, CancellationToken cancellationToken = default)
     {
         ArgumentNullException.ThrowIfNull(item);
 
@@ -592,12 +1187,6 @@ public sealed class BaseItemRepository
         }
     }
 
-    /// <inheritdoc  />
-    public void SaveItems(IReadOnlyList<BaseItemDto> items, CancellationToken cancellationToken)
-    {
-        UpdateOrInsertItems(items, cancellationToken);
-    }
-
     /// <inheritdoc cref="IItemRepository"/>
     public void UpdateOrInsertItems(IReadOnlyList<BaseItemDto> items, CancellationToken cancellationToken)
     {
@@ -746,13 +1335,195 @@ public sealed class BaseItemRepository
 
                 context.AncestorIds.RemoveRange(existingAncestorIds);
             }
+
+            if (item.Item is Folder folder)
+            {
+                var existingLinkedChildren = context.LinkedChildren.Where(e => e.ParentId == item.Item.Id).ToList();
+                if (folder.LinkedChildren.Length > 0)
+                {
+#pragma warning disable CS0618 // Type or member is obsolete - legacy path resolution for old data
+                    var pathsToResolve = folder.LinkedChildren
+                        .Where(lc => (!lc.ItemId.HasValue || lc.ItemId.Value.IsEmpty()) && !string.IsNullOrEmpty(lc.Path))
+                        .Select(lc => lc.Path)
+                        .Distinct()
+                        .ToList();
+
+                    var pathToIdMap = pathsToResolve.Count > 0
+                        ? context.BaseItems
+                            .Where(e => e.Path != null && pathsToResolve.Contains(e.Path))
+                            .Select(e => new { e.Path, e.Id })
+                            .ToDictionary(e => e.Path!, e => e.Id)
+                        : [];
+
+                    var resolvedChildren = new List<(LinkedChild Child, Guid ChildId)>();
+                    foreach (var linkedChild in folder.LinkedChildren)
+                    {
+                        var childItemId = linkedChild.ItemId;
+                        if (!childItemId.HasValue || childItemId.Value.IsEmpty())
+                        {
+                            if (!string.IsNullOrEmpty(linkedChild.Path) && pathToIdMap.TryGetValue(linkedChild.Path, out var resolvedId))
+                            {
+                                childItemId = resolvedId;
+                            }
+                        }
+#pragma warning restore CS0618
+
+                        if (childItemId.HasValue && !childItemId.Value.IsEmpty())
+                        {
+                            resolvedChildren.Add((linkedChild, childItemId.Value));
+                        }
+                    }
+
+                    var childIdsToCheck = resolvedChildren.Select(c => c.ChildId).Distinct().ToList();
+                    var existingChildIds = childIdsToCheck.Count > 0
+                        ? context.BaseItems
+                            .Where(e => childIdsToCheck.Contains(e.Id))
+                            .Select(e => e.Id)
+                            .ToHashSet()
+                        : [];
+
+                    var isPlaylist = folder is Playlist;
+                    var sortOrder = 0;
+                    foreach (var (linkedChild, childId) in resolvedChildren)
+                    {
+                        if (!existingChildIds.Contains(childId))
+                        {
+                            _logger.LogWarning(
+                                "Skipping LinkedChild for parent {ParentName} ({ParentId}): child item {ChildId} does not exist in database",
+                                item.Item.Name,
+                                item.Item.Id,
+                                childId);
+                            continue;
+                        }
+
+                        var existingLink = existingLinkedChildren.FirstOrDefault(e => e.ChildId == childId);
+                        if (existingLink is null)
+                        {
+                            context.LinkedChildren.Add(new LinkedChildEntity()
+                            {
+                                ParentId = item.Item.Id,
+                                ChildId = childId,
+                                ChildType = (DbLinkedChildType)linkedChild.Type,
+                                SortOrder = isPlaylist ? sortOrder : null
+                            });
+                        }
+                        else
+                        {
+                            existingLink.SortOrder = isPlaylist ? sortOrder : null;
+                            existingLink.ChildType = (DbLinkedChildType)linkedChild.Type;
+                            existingLinkedChildren.Remove(existingLink);
+                        }
+
+                        sortOrder++;
+                    }
+                }
+
+                if (existingLinkedChildren.Count > 0)
+                {
+                    context.LinkedChildren.RemoveRange(existingLinkedChildren);
+                }
+            }
+
+            // Handle Video alternate versions
+            if (item.Item is Video video)
+            {
+                var existingLinkedChildren = context.LinkedChildren
+                    .Where(e => e.ParentId == video.Id && ((int)e.ChildType == 2 || (int)e.ChildType == 3))
+                    .ToList();
+
+                var newLinkedChildren = new List<(Guid ChildId, LinkedChildType Type)>();
+
+                // Process LocalAlternateVersions (path-based alternate versions)
+                if (video.LocalAlternateVersions.Length > 0)
+                {
+                    var pathsToResolve = video.LocalAlternateVersions.Where(p => !string.IsNullOrEmpty(p)).ToList();
+                    if (pathsToResolve.Count > 0)
+                    {
+                        var pathToIdMap = context.BaseItems
+                            .Where(e => e.Path != null && pathsToResolve.Contains(e.Path))
+                            .Select(e => new { e.Path, e.Id })
+                            .ToDictionary(e => e.Path!, e => e.Id);
+
+                        foreach (var path in pathsToResolve)
+                        {
+                            if (pathToIdMap.TryGetValue(path, out var childId))
+                            {
+                                newLinkedChildren.Add((childId, LinkedChildType.LocalAlternateVersion));
+                            }
+                        }
+                    }
+                }
+
+                // Process LinkedAlternateVersions (ID-based alternate versions)
+                if (video.LinkedAlternateVersions.Length > 0)
+                {
+                    foreach (var linkedChild in video.LinkedAlternateVersions)
+                    {
+                        if (linkedChild.ItemId.HasValue && !linkedChild.ItemId.Value.IsEmpty())
+                        {
+                            newLinkedChildren.Add((linkedChild.ItemId.Value, LinkedChildType.LinkedAlternateVersion));
+                        }
+                    }
+                }
+
+                // Validate that all child items exist
+                var childIdsToCheck = newLinkedChildren.Select(c => c.ChildId).Distinct().ToList();
+                var existingChildIds = childIdsToCheck.Count > 0
+                    ? context.BaseItems
+                        .Where(e => childIdsToCheck.Contains(e.Id))
+                        .Select(e => e.Id)
+                        .ToHashSet()
+                    : [];
+
+                // Add or update LinkedChildren entries
+                foreach (var (childId, childType) in newLinkedChildren)
+                {
+                    if (!existingChildIds.Contains(childId))
+                    {
+                        _logger.LogWarning(
+                            "Skipping alternate version for video {VideoName} ({VideoId}): child item {ChildId} does not exist in database",
+                            video.Name,
+                            video.Id,
+                            childId);
+                        continue;
+                    }
+
+                    var existingLink = existingLinkedChildren.FirstOrDefault(e => e.ChildId == childId);
+                    if (existingLink is null)
+                    {
+                        context.LinkedChildren.Add(new LinkedChildEntity
+                        {
+                            ParentId = video.Id,
+                            ChildId = childId,
+                            ChildType = (DbLinkedChildType)childType,
+                            SortOrder = null
+                        });
+                    }
+                    else
+                    {
+                        existingLink.ChildType = (DbLinkedChildType)childType;
+                        existingLinkedChildren.Remove(existingLink);
+                    }
+                }
+
+                // Remove orphaned alternate version links
+                if (existingLinkedChildren.Count > 0)
+                {
+                    context.LinkedChildren.RemoveRange(existingLinkedChildren);
+                }
+            }
         }
 
         context.SaveChanges();
         transaction.Commit();
     }
 
-    /// <inheritdoc  />
+    /// <summary>
+    /// Reattaches user data entries that were incorrectly associated with a different item.
+    /// </summary>
+    /// <param name="item">The item DTO to reattach user data for.</param>
+    /// <param name="cancellationToken">The cancellation token.</param>
+    /// <returns>A task representing the asynchronous operation.</returns>
     public async Task ReattachUserDataAsync(BaseItemDto item, CancellationToken cancellationToken)
     {
         ArgumentNullException.ThrowIfNull(item);
@@ -795,7 +1566,8 @@ public sealed class BaseItemRepository
             .Include(e => e.Provider)
             .Include(e => e.LockedFields)
             .Include(e => e.UserData)
-            .Include(e => e.Images);
+            .Include(e => e.Images)
+            .Include(e => e.LinkedChildEntities);
 
         var item = dbQuery.FirstOrDefault(e => e.Id == id);
         if (item is null)
@@ -958,6 +1730,17 @@ public sealed class BaseItemRepository
         if (dto is Folder folder)
         {
             folder.DateLastMediaAdded = entity.DateLastMediaAdded ?? DateTime.SpecifyKind(DateTime.MinValue, DateTimeKind.Utc);
+            if (entity.LinkedChildEntities is not null && entity.LinkedChildEntities.Count > 0)
+            {
+                folder.LinkedChildren = entity.LinkedChildEntities
+                    .OrderBy(e => e.SortOrder)
+                    .Select(e => new LinkedChild
+                    {
+                        ItemId = e.ChildId,
+                        Type = (LinkedChildType)e.ChildType
+                    })
+                    .ToArray();
+            }
         }
 
         return dto;
@@ -1143,7 +1926,7 @@ public sealed class BaseItemRepository
 
         var query = context.ItemValuesMap
             .AsNoTracking()
-            .Where(e => itemValueTypes.Any(w => (ItemValueType)w == e.ItemValue.Type));
+            .Where(e => itemValueTypes.Any(w => w == e.ItemValue.Type));
         if (withItemTypes.Count > 0)
         {
             query = query.Where(e => withItemTypes.Contains(e.Item.Type));
@@ -1227,7 +2010,7 @@ public sealed class BaseItemRepository
     {
         ArgumentNullException.ThrowIfNull(filter);
 
-        if (!(filter.Limit.HasValue && filter.Limit.Value > 0))
+        if (!filter.Limit.HasValue)
         {
             filter.EnableTotalRecordCount = false;
         }
@@ -1250,15 +2033,13 @@ public sealed class BaseItemRepository
             IsNews = filter.IsNews,
             IsSeries = filter.IsSeries
         });
-
-        var itemValuesQuery = context.ItemValues
-            .Where(f => itemValueTypes.Contains(f.Type))
-            .SelectMany(f => f.BaseItemsMap!, (f, w) => new { f, w })
+        var itemValuesQuery = context.ItemValuesMap
+            .Where(ivm => itemValueTypes.Contains(ivm.ItemValue.Type))
             .Join(
                 innerQueryFilter,
-                fw => fw.w.ItemId,
+                ivm => ivm.ItemId,
                 g => g.Id,
-                (fw, g) => fw.f.CleanValue);
+                (ivm, g) => ivm.ItemValue.CleanValue);
 
         var innerQuery = PrepareItemQuery(context, filter)
             .Where(e => e.Type == returnType)
@@ -1295,6 +2076,7 @@ public sealed class BaseItemRepository
             .Include(e => e.Provider)
             .Include(e => e.LockedFields)
             .Include(e => e.Images)
+            .Include(e => e.LinkedChildEntities)
             .AsSingleQuery()
             .Where(e => masterQuery.Contains(e.Id));
 
@@ -1306,22 +2088,23 @@ public sealed class BaseItemRepository
             result.TotalRecordCount = query.Count();
         }
 
-        if (filter.StartIndex.HasValue && filter.StartIndex.Value > 0)
+        if (filter.Limit.HasValue || filter.StartIndex.HasValue)
         {
-            query = query.Skip(filter.StartIndex.Value);
-        }
+            var offset = filter.StartIndex ?? 0;
 
-        if (filter.Limit.HasValue && filter.Limit.Value > 0)
-        {
-            query = query.Take(filter.Limit.Value);
-        }
+            if (offset > 0)
+            {
+                query = query.Skip(offset);
+            }
 
-        IQueryable<BaseItemEntity>? itemCountQuery = null;
+            if (filter.Limit.HasValue)
+            {
+                query = query.Take(filter.Limit.Value);
+            }
+        }
 
         if (filter.IncludeItemTypes.Length > 0)
         {
-            // if we are to include more then one type, sub query those items beforehand.
-
             var typeSubQuery = new InternalItemsQuery(filter.User)
             {
                 ExcludeItemTypes = filter.ExcludeItemTypes,
@@ -1335,7 +2118,7 @@ public sealed class BaseItemRepository
                 IsPlayed = filter.IsPlayed
             };
 
-            itemCountQuery = TranslateQuery(context.BaseItems.AsNoTracking().Where(e => e.Id != EF.Constant(PlaceholderId)), context, typeSubQuery)
+            var itemCountQuery = TranslateQuery(context.BaseItems.AsNoTracking().Where(e => e.Id != EF.Constant(PlaceholderId)), context, typeSubQuery)
                 .Where(e => e.ItemValues!.Any(f => itemValueTypes!.Contains(f.ItemValue.Type)));
 
             var seriesTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Series];
@@ -1346,31 +2129,49 @@ public sealed class BaseItemRepository
             var audioTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Audio];
             var trailerTypeName = _itemTypeLookup.BaseItemKindNames[BaseItemKind.Trailer];
 
-            var resultQuery = query.Select(e => new
-            {
-                item = e,
-                // TODO: This is bad refactor!
-                itemCount = new ItemCounts()
-                {
-                    SeriesCount = itemCountQuery!.Count(f => f.Type == seriesTypeName),
-                    EpisodeCount = itemCountQuery!.Count(f => f.Type == episodeTypeName),
-                    MovieCount = itemCountQuery!.Count(f => f.Type == movieTypeName),
-                    AlbumCount = itemCountQuery!.Count(f => f.Type == musicAlbumTypeName),
-                    ArtistCount = itemCountQuery!.Count(f => f.Type == musicArtistTypeName),
-                    SongCount = itemCountQuery!.Count(f => f.Type == audioTypeName),
-                    TrailerCount = itemCountQuery!.Count(f => f.Type == trailerTypeName),
-                }
-            });
+            // Get the IDs from itemCountQuery to use in the join
+            var itemIds = itemCountQuery.Select(e => e.Id);
+
+            // Rewrite query to avoid SelectMany on navigation properties (which requires SQL APPLY, not supported on SQLite)
+            // Instead, start from ItemValueMaps and join with BaseItems
+            var countsByCleanName = context.ItemValuesMap
+                .Where(ivm => itemValueTypes.Contains(ivm.ItemValue.Type))
+                .Where(ivm => itemIds.Contains(ivm.ItemId))
+                .Join(
+                    context.BaseItems,
+                    ivm => ivm.ItemId,
+                    e => e.Id,
+                    (ivm, e) => new { CleanName = ivm.ItemValue.CleanValue, e.Type })
+                .GroupBy(x => new { x.CleanName, x.Type })
+                .Select(g => new { g.Key.CleanName, g.Key.Type, Count = g.Count() })
+                .GroupBy(x => x.CleanName)
+                .ToDictionary(
+                    g => g.Key,
+                    g => new ItemCounts
+                    {
+                        SeriesCount = g.Where(x => x.Type == seriesTypeName).Sum(x => x.Count),
+                        EpisodeCount = g.Where(x => x.Type == episodeTypeName).Sum(x => x.Count),
+                        MovieCount = g.Where(x => x.Type == movieTypeName).Sum(x => x.Count),
+                        AlbumCount = g.Where(x => x.Type == musicAlbumTypeName).Sum(x => x.Count),
+                        ArtistCount = g.Where(x => x.Type == musicArtistTypeName).Sum(x => x.Count),
+                        SongCount = g.Where(x => x.Type == audioTypeName).Sum(x => x.Count),
+                        TrailerCount = g.Where(x => x.Type == trailerTypeName).Sum(x => x.Count),
+                    });
 
             result.StartIndex = filter.StartIndex ?? 0;
             result.Items =
             [
-                .. resultQuery
+                .. query
                     .AsEnumerable()
                     .Where(e => e is not null)
-                    .Select(e => (Item: DeserializeBaseItem(e.item, filter.SkipDeserialization), e.itemCount))
-                    .Where(e => e.Item is not null)
-                    .Select(e => (e.Item!, e.itemCount))
+                    .Select(e =>
+                    {
+                        var item = DeserializeBaseItem(e, filter.SkipDeserialization);
+                        countsByCleanName.TryGetValue(e.CleanName ?? string.Empty, out var itemCount);
+                        return (item, itemCount);
+                    })
+                    .Where(x => x.item is not null)
+                    .Select(x => (x.item!, x.itemCount))
             ];
         }
         else
@@ -1381,9 +2182,9 @@ public sealed class BaseItemRepository
                 .. query
                     .AsEnumerable()
                     .Where(e => e is not null)
-                    .Select(e => (Item: DeserializeBaseItem(e, filter.SkipDeserialization), ItemCounts: (ItemCounts?)null))
-                    .Where(e => e.Item is not null)
-                    .Select(e => (e.Item!, e.ItemCounts))
+                    .Select(e => DeserializeBaseItem(e, filter.SkipDeserialization))
+                    .Where(item => item is not null)
+                    .Select(item => (item!, (ItemCounts?)null))
             ];
         }
 
@@ -1392,7 +2193,7 @@ public sealed class BaseItemRepository
 
     private static void PrepareFilterQuery(InternalItemsQuery query)
     {
-        if (query.Limit.HasValue && query.Limit.Value > 0 && query.EnableGroupByMetadataKey)
+        if (query.Limit.HasValue && query.EnableGroupByMetadataKey)
         {
             query.Limit = query.Limit.Value + 4;
         }
@@ -1404,10 +2205,10 @@ public sealed class BaseItemRepository
     }
 
     /// <summary>
-    /// Gets the clean value for search and sorting purposes.
+    /// Normalizes a value for clean comparison by removing diacritics and converting to lowercase.
     /// </summary>
     /// <param name="value">The value to clean.</param>
-    /// <returns>The cleaned value.</returns>
+    /// <returns>The normalized value.</returns>
     public static string GetCleanValue(string value)
     {
         if (string.IsNullOrWhiteSpace(value))
@@ -1415,42 +2216,7 @@ public sealed class BaseItemRepository
             return value;
         }
 
-        var noDiacritics = value.RemoveDiacritics();
-
-        // Build a string where any punctuation or symbol is treated as a separator (space).
-        var sb = new StringBuilder(noDiacritics.Length);
-        var previousWasSpace = false;
-        foreach (var ch in noDiacritics)
-        {
-            char outCh;
-            if (char.IsLetterOrDigit(ch) || char.IsWhiteSpace(ch))
-            {
-                outCh = ch;
-            }
-            else
-            {
-                outCh = ' ';
-            }
-
-            // normalize any whitespace character to a single ASCII space.
-            if (char.IsWhiteSpace(outCh))
-            {
-                if (!previousWasSpace)
-                {
-                    sb.Append(' ');
-                    previousWasSpace = true;
-                }
-            }
-            else
-            {
-                sb.Append(outCh);
-                previousWasSpace = false;
-            }
-        }
-
-        // trim leading/trailing spaces that may have been added.
-        var collapsed = sb.ToString().Trim();
-        return collapsed.ToLowerInvariant();
+        return value.RemoveDiacritics().ToLowerInvariant();
     }
 
     private List<(ItemValueType MagicNumber, string Value)> GetItemValuesToSave(BaseItemDto item, List<string> inheritedTags)
@@ -1602,37 +2368,27 @@ public sealed class BaseItemRepository
         var orderBy = filter.OrderBy.Where(e => e.OrderBy != ItemSortBy.Default).ToArray();
         var hasSearch = !string.IsNullOrEmpty(filter.SearchTerm);
 
-        if (hasSearch)
-        {
-            orderBy = [(ItemSortBy.SortName, SortOrder.Ascending), .. orderBy];
-        }
-        else if (orderBy.Length == 0)
-        {
-            return query.OrderBy(e => e.SortName);
-        }
-
         IOrderedQueryable<BaseItemEntity>? orderedQuery = null;
 
-        // When searching, prioritize by match quality: exact match > prefix match > contains
         if (hasSearch)
         {
-            orderedQuery = query.OrderBy(OrderMapper.MapSearchRelevanceOrder(filter.SearchTerm!));
+            var relevanceExpression = OrderMapper.MapSearchRelevanceOrder(filter.SearchTerm!);
+            orderedQuery = query.OrderBy(relevanceExpression);
         }
 
-        var firstOrdering = orderBy.FirstOrDefault();
-        if (firstOrdering != default)
+        if (orderBy.Length > 0)
         {
+            var firstOrdering = orderBy[0];
             var expression = OrderMapper.MapOrderByField(firstOrdering.OrderBy, filter, context);
+
             if (orderedQuery is null)
             {
-                // No search relevance ordering, start fresh
                 orderedQuery = firstOrdering.SortOrder == SortOrder.Ascending
                     ? query.OrderBy(expression)
                     : query.OrderByDescending(expression);
             }
             else
             {
-                // Search relevance ordering already applied, chain with ThenBy
                 orderedQuery = firstOrdering.SortOrder == SortOrder.Ascending
                     ? orderedQuery.ThenBy(expression)
                     : orderedQuery.ThenByDescending(expression);
@@ -1640,26 +2396,32 @@ public sealed class BaseItemRepository
 
             if (firstOrdering.OrderBy is ItemSortBy.Default or ItemSortBy.SortName)
             {
-                orderedQuery = firstOrdering.SortOrder is SortOrder.Ascending
+                orderedQuery = firstOrdering.SortOrder == SortOrder.Ascending
                     ? orderedQuery.ThenBy(e => e.Name)
                     : orderedQuery.ThenByDescending(e => e.Name);
             }
-        }
 
-        foreach (var item in orderBy.Skip(1))
-        {
-            var expression = OrderMapper.MapOrderByField(item.OrderBy, filter, context);
-            if (item.SortOrder == SortOrder.Ascending)
+            foreach (var item in orderBy.Skip(1))
             {
-                orderedQuery = orderedQuery!.ThenBy(expression);
-            }
-            else
-            {
-                orderedQuery = orderedQuery!.ThenByDescending(expression);
+                expression = OrderMapper.MapOrderByField(item.OrderBy, filter, context);
+                orderedQuery = item.SortOrder == SortOrder.Ascending
+                    ? orderedQuery.ThenBy(expression)
+                    : orderedQuery.ThenByDescending(expression);
             }
         }
 
-        return orderedQuery ?? query;
+        if (orderedQuery is null)
+        {
+            return query.OrderBy(e => e.SortName);
+        }
+
+        // Add SortName as final tiebreaker
+        if (!hasSearch && (orderBy.Length == 0 || orderBy.All(o => o.OrderBy is not ItemSortBy.SortName and not ItemSortBy.Name)))
+        {
+            orderedQuery = orderedQuery.ThenBy(e => e.SortName);
+        }
+
+        return orderedQuery;
     }
 
     private IQueryable<BaseItemEntity> TranslateQuery(
@@ -1787,15 +2549,17 @@ public sealed class BaseItemRepository
         if (!string.IsNullOrEmpty(filter.SearchTerm))
         {
             var cleanedSearchTerm = GetCleanValue(filter.SearchTerm);
-            var originalSearchTerm = filter.SearchTerm.ToLower();
+            var originalSearchTerm = filter.SearchTerm;
             if (SearchWildcardTerms.Any(f => cleanedSearchTerm.Contains(f)))
             {
                 cleanedSearchTerm = $"%{cleanedSearchTerm.Trim('%')}%";
-                baseQuery = baseQuery.Where(e => EF.Functions.Like(e.CleanName!, cleanedSearchTerm) || (e.OriginalTitle != null && EF.Functions.Like(e.OriginalTitle.ToLower(), originalSearchTerm)));
+                var likeSearchTerm = $"%{originalSearchTerm.Trim('%')}%";
+                baseQuery = baseQuery.Where(e => EF.Functions.Like(e.CleanName!, cleanedSearchTerm) || (e.OriginalTitle != null && EF.Functions.Like(e.OriginalTitle, likeSearchTerm)));
             }
             else
             {
-                baseQuery = baseQuery.Where(e => e.CleanName!.Contains(cleanedSearchTerm) || (e.OriginalTitle != null && e.OriginalTitle.ToLower().Contains(originalSearchTerm)));
+                var likeSearchTerm = $"%{originalSearchTerm}%";
+                baseQuery = baseQuery.Where(e => e.CleanName!.Contains(cleanedSearchTerm) || (e.OriginalTitle != null && EF.Functions.Like(e.OriginalTitle, likeSearchTerm)));
             }
         }
 
@@ -2029,28 +2793,29 @@ public sealed class BaseItemRepository
             }
             else
             {
+                var likeNameContains = $"%{nameContains}%";
                 baseQuery = baseQuery.Where(e =>
                                     e.CleanName!.Contains(nameContains)
-                                    || e.OriginalTitle!.ToLower().Contains(nameContains!));
+                                    || EF.Functions.Like(e.OriginalTitle, likeNameContains));
             }
         }
 
         if (!string.IsNullOrWhiteSpace(filter.NameStartsWith))
         {
-            var startsWithLower = filter.NameStartsWith.ToLowerInvariant();
-            baseQuery = baseQuery.Where(e => e.SortName!.StartsWith(startsWithLower));
+            var nameStartsWithLower = filter.NameStartsWith.ToLowerInvariant();
+            baseQuery = baseQuery.Where(e => e.SortName!.ToLower().StartsWith(nameStartsWithLower));
         }
 
         if (!string.IsNullOrWhiteSpace(filter.NameStartsWithOrGreater))
         {
             var startsOrGreaterLower = filter.NameStartsWithOrGreater.ToLowerInvariant();
-            baseQuery = baseQuery.Where(e => e.SortName!.CompareTo(startsOrGreaterLower) >= 0);
+            baseQuery = baseQuery.Where(e => e.SortName!.ToLower().CompareTo(startsOrGreaterLower) >= 0);
         }
 
         if (!string.IsNullOrWhiteSpace(filter.NameLessThan))
         {
             var lessThanLower = filter.NameLessThan.ToLowerInvariant();
-            baseQuery = baseQuery.Where(e => e.SortName!.CompareTo(lessThanLower ) < 0);
+            baseQuery = baseQuery.Where(e => e.SortName!.ToLower().CompareTo(lessThanLower) < 0);
         }
 
         if (filter.ImageTypes.Length > 0)
@@ -2082,21 +2847,46 @@ public sealed class BaseItemRepository
             // We should probably figure this out for all folders, but for right now, this is the only place where we need it
             if (filter.IncludeItemTypes.Length == 1 && filter.IncludeItemTypes[0] == BaseItemKind.Series)
             {
-                baseQuery = baseQuery.Where(e => context.BaseItems.Where(e => e.Id != EF.Constant(PlaceholderId))
-                    .Where(e => e.IsFolder == false && e.IsVirtualItem == false)
-                    .Where(f => f.UserData!.FirstOrDefault(e => e.UserId == filter.User!.Id && e.Played)!.Played)
-                    .Any(f => f.SeriesPresentationUniqueKey == e.PresentationUniqueKey) == filter.IsPlayed);
+                // Get distinct SeriesPresentationUniqueKeys that have at least one played episode
+                var playedSeriesKeys = context.BaseItems
+                    .Where(e => !e.IsFolder && !e.IsVirtualItem && e.SeriesPresentationUniqueKey != null)
+                    .Where(e => e.UserData!.Any(ud => ud.UserId == filter.User!.Id && ud.Played))
+                    .Select(e => e.SeriesPresentationUniqueKey!)
+                    .Distinct()
+                    .ToHashSet();
+
+                if (filter.IsPlayed.Value)
+                {
+                    if (playedSeriesKeys.Count == 0)
+                    {
+                        baseQuery = baseQuery.Where(e => false);
+                    }
+                    else
+                    {
+                        baseQuery = baseQuery.Where(e => playedSeriesKeys.Contains(e.PresentationUniqueKey!));
+                    }
+                }
+                else
+                {
+                    if (playedSeriesKeys.Count == 0)
+                    {
+                        // No played episodes - all series are unplayed, no filter needed
+                    }
+                    else
+                    {
+                        baseQuery = baseQuery.Where(e => !playedSeriesKeys.Contains(e.PresentationUniqueKey!));
+                    }
+                }
+            }
+            else if (filter.IsPlayed.Value)
+            {
+                baseQuery = baseQuery
+                    .Where(e => e.UserData!.Any(f => f.UserId == filter.User!.Id && f.Played));
             }
             else
             {
                 baseQuery = baseQuery
-                    .Select(e => new
-                    {
-                        IsPlayed = e.UserData!.Where(f => f.UserId == filter.User!.Id).Select(f => (bool?)f.Played).FirstOrDefault() ?? false,
-                        Item = e
-                    })
-                    .Where(e => e.IsPlayed == filter.IsPlayed)
-                    .Select(f => f.Item);
+                    .Where(e => !e.UserData!.Any(f => f.UserId == filter.User!.Id && f.Played));
             }
         }
 
@@ -2184,8 +2974,10 @@ public sealed class BaseItemRepository
 
         if (filter.OfficialRatings.Length > 0)
         {
-            baseQuery = baseQuery
-                   .Where(e => filter.OfficialRatings.Contains(e.OfficialRating));
+            var ratings = filter.OfficialRatings;
+            Expression<Func<BaseItemEntity, bool>> hasOfficialRating = e => ratings.Contains(e.OfficialRating);
+
+            baseQuery = baseQuery.WhereItemOrDescendantMatches(context, hasOfficialRating);
         }
 
         Expression<Func<BaseItemEntity, bool>>? minParentalRatingFilter = null;
@@ -2268,16 +3060,12 @@ public sealed class BaseItemRepository
 
         if (filter.HasOfficialRating.HasValue)
         {
-            if (filter.HasOfficialRating.Value)
-            {
-                baseQuery = baseQuery
-                    .Where(e => e.OfficialRating != null && e.OfficialRating != string.Empty);
-            }
-            else
-            {
-                baseQuery = baseQuery
-                    .Where(e => e.OfficialRating == null || e.OfficialRating == string.Empty);
-            }
+            Expression<Func<BaseItemEntity, bool>> hasRating =
+                e => e.OfficialRating != null && e.OfficialRating != string.Empty;
+
+            baseQuery = filter.HasOfficialRating.Value
+                ? baseQuery.WhereItemOrDescendantMatches(context, hasRating)
+                : baseQuery.WhereNeitherItemNorDescendantMatches(context, hasRating);
         }
 
         if (filter.HasOverview.HasValue)
@@ -2321,38 +3109,86 @@ public sealed class BaseItemRepository
 
         if (!string.IsNullOrWhiteSpace(filter.HasNoAudioTrackWithLanguage))
         {
+            var lang = filter.HasNoAudioTrackWithLanguage;
+            var foldersWithAudio = _descendantQueryProvider.GetFolderIdsMatching(context, new HasMediaStreamType(MediaStreamTypeEntity.Audio, lang));
+
             baseQuery = baseQuery
-                .Where(e => !e.MediaStreams!.Any(f => f.StreamType == MediaStreamTypeEntity.Audio && f.Language == filter.HasNoAudioTrackWithLanguage));
+                .Where(e =>
+                    (!e.IsFolder && !e.MediaStreams!.Any(ms => ms.StreamType == MediaStreamTypeEntity.Audio && ms.Language == lang))
+                    || (e.IsFolder && !foldersWithAudio.Contains(e.Id)));
         }
 
         if (!string.IsNullOrWhiteSpace(filter.HasNoInternalSubtitleTrackWithLanguage))
         {
+            var lang = filter.HasNoInternalSubtitleTrackWithLanguage;
+            var foldersWithSubtitles = _descendantQueryProvider.GetFolderIdsMatching(context, new HasMediaStreamType(MediaStreamTypeEntity.Subtitle, lang, IsExternal: false));
+
             baseQuery = baseQuery
-                .Where(e => !e.MediaStreams!.Any(f => f.StreamType == MediaStreamTypeEntity.Subtitle && !f.IsExternal && f.Language == filter.HasNoInternalSubtitleTrackWithLanguage));
+                .Where(e =>
+                    (!e.IsFolder && !e.MediaStreams!.Any(ms => ms.StreamType == MediaStreamTypeEntity.Subtitle && !ms.IsExternal && ms.Language == lang))
+                    || (e.IsFolder && !foldersWithSubtitles.Contains(e.Id)));
         }
 
         if (!string.IsNullOrWhiteSpace(filter.HasNoExternalSubtitleTrackWithLanguage))
         {
+            var lang = filter.HasNoExternalSubtitleTrackWithLanguage;
+            var foldersWithSubtitles = _descendantQueryProvider.GetFolderIdsMatching(context, new HasMediaStreamType(MediaStreamTypeEntity.Subtitle, lang, IsExternal: true));
+
             baseQuery = baseQuery
-                .Where(e => !e.MediaStreams!.Any(f => f.StreamType == MediaStreamTypeEntity.Subtitle && f.IsExternal && f.Language == filter.HasNoExternalSubtitleTrackWithLanguage));
+                .Where(e =>
+                    (!e.IsFolder && !e.MediaStreams!.Any(ms => ms.StreamType == MediaStreamTypeEntity.Subtitle && ms.IsExternal && ms.Language == lang))
+                    || (e.IsFolder && !foldersWithSubtitles.Contains(e.Id)));
         }
 
         if (!string.IsNullOrWhiteSpace(filter.HasNoSubtitleTrackWithLanguage))
         {
+            var lang = filter.HasNoSubtitleTrackWithLanguage;
+            var foldersWithSubtitles = _descendantQueryProvider.GetFolderIdsMatching(context, new HasMediaStreamType(MediaStreamTypeEntity.Subtitle, lang));
+
             baseQuery = baseQuery
-                .Where(e => !e.MediaStreams!.Any(f => f.StreamType == MediaStreamTypeEntity.Subtitle && f.Language == filter.HasNoSubtitleTrackWithLanguage));
+                .Where(e =>
+                    (!e.IsFolder && !e.MediaStreams!.Any(ms => ms.StreamType == MediaStreamTypeEntity.Subtitle && ms.Language == lang))
+                    || (e.IsFolder && !foldersWithSubtitles.Contains(e.Id)));
         }
 
         if (filter.HasSubtitles.HasValue)
         {
-            baseQuery = baseQuery
-                .Where(e => e.MediaStreams!.Any(f => f.StreamType == MediaStreamTypeEntity.Subtitle) == filter.HasSubtitles.Value);
+            var hasSubtitles = filter.HasSubtitles.Value;
+            var foldersWithSubtitles = _descendantQueryProvider.GetFolderIdsMatching(context, new HasSubtitles());
+            if (hasSubtitles)
+            {
+                baseQuery = baseQuery
+                    .Where(e =>
+                        (!e.IsFolder && e.MediaStreams!.Any(f => f.StreamType == MediaStreamTypeEntity.Subtitle))
+                        || (e.IsFolder && foldersWithSubtitles.Contains(e.Id)));
+            }
+            else
+            {
+                baseQuery = baseQuery
+                    .Where(e =>
+                        (!e.IsFolder && !e.MediaStreams!.Any(f => f.StreamType == MediaStreamTypeEntity.Subtitle))
+                        || (e.IsFolder && !foldersWithSubtitles.Contains(e.Id)));
+            }
         }
 
         if (filter.HasChapterImages.HasValue)
         {
-            baseQuery = baseQuery
-                .Where(e => e.Chapters!.Any(f => f.ImagePath != null) == filter.HasChapterImages.Value);
+            var hasChapterImages = filter.HasChapterImages.Value;
+            var foldersWithChapterImages = _descendantQueryProvider.GetFolderIdsMatching(context, new HasChapterImages());
+            if (hasChapterImages)
+            {
+                baseQuery = baseQuery
+                    .Where(e =>
+                        (!e.IsFolder && e.Chapters!.Any(f => f.ImagePath != null))
+                        || (e.IsFolder && foldersWithChapterImages.Contains(e.Id)));
+            }
+            else
+            {
+                baseQuery = baseQuery
+                    .Where(e =>
+                        (!e.IsFolder && !e.Chapters!.Any(f => f.ImagePath != null))
+                        || (e.IsFolder && !foldersWithChapterImages.Contains(e.Id)));
+            }
         }
 
         if (filter.HasDeadParentId.HasValue && filter.HasDeadParentId.Value)
@@ -2467,22 +3303,22 @@ public sealed class BaseItemRepository
         if (filter.HasImdbId.HasValue)
         {
             baseQuery = filter.HasImdbId.Value
-                ? baseQuery.Where(e => e.Provider!.Any(f => f.ProviderId.ToLower() == MetadataProvider.Imdb.ToString().ToLower()))
-                : baseQuery.Where(e => e.Provider!.All(f => f.ProviderId.ToLower() != MetadataProvider.Imdb.ToString().ToLower()));
+                ? baseQuery.Where(e => e.Provider!.Any(f => f.ProviderId.ToLower() == ImdbProviderName))
+                : baseQuery.Where(e => e.Provider!.All(f => f.ProviderId.ToLower() != ImdbProviderName));
         }
 
         if (filter.HasTmdbId.HasValue)
         {
             baseQuery = filter.HasTmdbId.Value
-                ? baseQuery.Where(e => e.Provider!.Any(f => f.ProviderId.ToLower() == MetadataProvider.Tmdb.ToString().ToLower()))
-                : baseQuery.Where(e => e.Provider!.All(f => f.ProviderId.ToLower() != MetadataProvider.Tmdb.ToString().ToLower()));
+                ? baseQuery.Where(e => e.Provider!.Any(f => f.ProviderId.ToLower() == TmdbProviderName))
+                : baseQuery.Where(e => e.Provider!.All(f => f.ProviderId.ToLower() != TmdbProviderName));
         }
 
         if (filter.HasTvdbId.HasValue)
         {
             baseQuery = filter.HasTvdbId.Value
-                ? baseQuery.Where(e => e.Provider!.Any(f => f.ProviderId.ToLower() == MetadataProvider.Tvdb.ToString().ToLower()))
-                : baseQuery.Where(e => e.Provider!.All(f => f.ProviderId.ToLower() != MetadataProvider.Tvdb.ToString().ToLower()));
+                ? baseQuery.Where(e => e.Provider!.Any(f => f.ProviderId.ToLower() == TvdbProviderName))
+                : baseQuery.Where(e => e.Provider!.All(f => f.ProviderId.ToLower() != TvdbProviderName));
         }
 
         var queryTopParentIds = filter.TopParentIds;
@@ -2503,7 +3339,8 @@ public sealed class BaseItemRepository
 
         if (filter.AncestorIds.Length > 0)
         {
-            baseQuery = baseQuery.Where(e => e.Parents!.Any(f => filter.AncestorIds.Contains(f.ParentItemId)));
+            var ancestorFilter = filter.AncestorIds.OneOrManyExpressionBuilder<AncestorId, Guid>(f => f.ParentItemId);
+            baseQuery = baseQuery.Where(e => e.Parents!.AsQueryable().Any(ancestorFilter));
         }
 
         if (!string.IsNullOrWhiteSpace(filter.AncestorWithPresentationUniqueKey))
@@ -2522,8 +3359,10 @@ public sealed class BaseItemRepository
         {
             var excludedTags = filter.ExcludeInheritedTags;
             baseQuery = baseQuery.Where(e =>
-                !e.ItemValues!.Any(f => f.ItemValue.Type == ItemValueType.Tags && excludedTags.Contains(f.ItemValue.CleanValue))
-                && (!e.SeriesId.HasValue || !context.ItemValuesMap.Any(f => f.ItemId == e.SeriesId.Value && f.ItemValue.Type == ItemValueType.Tags && excludedTags.Contains(f.ItemValue.CleanValue))));
+                !context.ItemValuesMap.Any(f =>
+                    f.ItemValue.Type == ItemValueType.Tags
+                    && excludedTags.Contains(f.ItemValue.CleanValue)
+                    && (f.ItemId == e.Id || (e.SeriesId.HasValue && f.ItemId == e.SeriesId.Value))));
         }
 
         if (filter.IncludeInheritedTags.Length > 0)
@@ -2531,10 +3370,10 @@ public sealed class BaseItemRepository
             var includeTags = filter.IncludeInheritedTags;
             var isPlaylistOnlyQuery = includeTypes.Length == 1 && includeTypes.FirstOrDefault() == BaseItemKind.Playlist;
             baseQuery = baseQuery.Where(e =>
-                e.ItemValues!.Any(f => f.ItemValue.Type == ItemValueType.Tags && includeTags.Contains(f.ItemValue.CleanValue))
-
-                // For seasons and episodes, we also need to check the parent series' tags.
-                || (e.SeriesId.HasValue && context.ItemValuesMap.Any(f => f.ItemId == e.SeriesId.Value && f.ItemValue.Type == ItemValueType.Tags && includeTags.Contains(f.ItemValue.CleanValue)))
+                context.ItemValuesMap.Any(f =>
+                    f.ItemValue.Type == ItemValueType.Tags
+                    && includeTags.Contains(f.ItemValue.CleanValue)
+                    && (f.ItemId == e.Id || (e.SeriesId.HasValue && f.ItemId == e.SeriesId.Value)))
 
                 // A playlist should be accessible to its owner regardless of allowed tags
                 || (isPlaylistOnlyQuery && e.Data!.Contains($"OwnerUserId\":\"{filter.User!.Id:N}\"")));
@@ -2556,64 +3395,131 @@ public sealed class BaseItemRepository
 
         if (filter.VideoTypes.Length > 0)
         {
-            var videoTypeBs = filter.VideoTypes.Select(e => $"\"VideoType\":\"{e}\"");
-            baseQuery = baseQuery
-                .Where(e => videoTypeBs.Any(f => e.Data!.Contains(f)));
+            var videoTypeBs = filter.VideoTypes.Select(vt => $"\"VideoType\":\"{vt}\"").ToArray();
+            Expression<Func<BaseItemEntity, bool>> hasVideoType = e => videoTypeBs.Any(f => e.Data!.Contains(f));
+            baseQuery = baseQuery.WhereItemOrDescendantMatches(context, hasVideoType);
         }
 
         if (filter.Is3D.HasValue)
         {
-            if (filter.Is3D.Value)
-            {
-                baseQuery = baseQuery
-                    .Where(e => e.Data!.Contains("Video3DFormat"));
-            }
-            else
-            {
-                baseQuery = baseQuery
-                    .Where(e => !e.Data!.Contains("Video3DFormat"));
-            }
+            Expression<Func<BaseItemEntity, bool>> is3D = e => e.Data!.Contains("Video3DFormat");
+
+            baseQuery = filter.Is3D.Value
+                ? baseQuery.WhereItemOrDescendantMatches(context, is3D)
+                : baseQuery.WhereNeitherItemNorDescendantMatches(context, is3D);
         }
 
         if (filter.IsPlaceHolder.HasValue)
         {
-            if (filter.IsPlaceHolder.Value)
-            {
-                baseQuery = baseQuery
-                    .Where(e => e.Data!.Contains("IsPlaceHolder\":true"));
-            }
-            else
-            {
-                baseQuery = baseQuery
-                    .Where(e => !e.Data!.Contains("IsPlaceHolder\":true"));
-            }
+            Expression<Func<BaseItemEntity, bool>> isPlaceHolder = e => e.Data!.Contains("IsPlaceHolder\":true");
+
+            baseQuery = filter.IsPlaceHolder.Value
+                ? baseQuery.WhereItemOrDescendantMatches(context, isPlaceHolder)
+                : baseQuery.WhereNeitherItemNorDescendantMatches(context, isPlaceHolder);
         }
 
         if (filter.HasSpecialFeature.HasValue)
         {
-            if (filter.HasSpecialFeature.Value)
+            var itemsWithExtras = context.BaseItems
+                .Where(extra => extra.OwnerId != null)
+                .Select(extra => extra.OwnerId!.Value)
+                .Distinct();
+
+            Expression<Func<BaseItemEntity, bool>> hasExtras = e => itemsWithExtras.Contains(e.Id);
+
+            baseQuery = filter.HasSpecialFeature.Value
+                ? baseQuery.WhereItemOrDescendantMatches(context, hasExtras)
+                : baseQuery.WhereNeitherItemNorDescendantMatches(context, hasExtras);
+        }
+
+        if (filter.HasTrailer.HasValue)
+        {
+            var trailerOwnerIds = context.BaseItems
+                .Where(extra => extra.ExtraType == BaseItemExtraType.Trailer && extra.OwnerId != null)
+                .Select(extra => extra.OwnerId!.Value);
+
+            Expression<Func<BaseItemEntity, bool>> hasTrailer = e => trailerOwnerIds.Contains(e.Id);
+
+            baseQuery = filter.HasTrailer.Value
+                ? baseQuery.WhereItemOrDescendantMatches(context, hasTrailer)
+                : baseQuery.WhereNeitherItemNorDescendantMatches(context, hasTrailer);
+        }
+
+        if (filter.HasThemeSong.HasValue)
+        {
+            var themeSongOwnerIds = context.BaseItems
+                .Where(extra => extra.ExtraType == BaseItemExtraType.ThemeSong && extra.OwnerId != null)
+                .Select(extra => extra.OwnerId!.Value);
+
+            Expression<Func<BaseItemEntity, bool>> hasThemeSong = e => themeSongOwnerIds.Contains(e.Id);
+
+            baseQuery = filter.HasThemeSong.Value
+                ? baseQuery.WhereItemOrDescendantMatches(context, hasThemeSong)
+                : baseQuery.WhereNeitherItemNorDescendantMatches(context, hasThemeSong);
+        }
+
+        if (filter.HasThemeVideo.HasValue)
+        {
+            var themeVideoOwnerIds = context.BaseItems
+                .Where(extra => extra.ExtraType == BaseItemExtraType.ThemeVideo && extra.OwnerId != null)
+                .Select(extra => extra.OwnerId!.Value);
+
+            Expression<Func<BaseItemEntity, bool>> hasThemeVideo = e => themeVideoOwnerIds.Contains(e.Id);
+
+            baseQuery = filter.HasThemeVideo.Value
+                ? baseQuery.WhereItemOrDescendantMatches(context, hasThemeVideo)
+                : baseQuery.WhereNeitherItemNorDescendantMatches(context, hasThemeVideo);
+        }
+
+        if (filter.AiredDuringSeason.HasValue)
+        {
+            var seasonNumber = filter.AiredDuringSeason.Value;
+            if (seasonNumber < 1)
             {
-                baseQuery = baseQuery
-                    .Where(e => e.Extras != null && e.Extras.Count > 0);
+                baseQuery = baseQuery.Where(e => e.ParentIndexNumber == seasonNumber);
             }
             else
             {
-                baseQuery = baseQuery
-                    .Where(e => e.Extras == null || e.Extras.Count == 0);
+                var seasonStr = seasonNumber.ToString(CultureInfo.InvariantCulture);
+                baseQuery = baseQuery.Where(e =>
+                    e.ParentIndexNumber == seasonNumber
+                    || (e.Data != null && (
+                        e.Data.Contains("\"AirsAfterSeasonNumber\":" + seasonStr)
+                        || e.Data.Contains("\"AirsBeforeSeasonNumber\":" + seasonStr))));
             }
         }
 
-        if (filter.HasTrailer.HasValue || filter.HasThemeSong.HasValue || filter.HasThemeVideo.HasValue)
+        if (filter.AdjacentTo.HasValue && !filter.AdjacentTo.Value.IsEmpty())
         {
-            if (filter.HasTrailer.GetValueOrDefault() || filter.HasThemeSong.GetValueOrDefault() || filter.HasThemeVideo.GetValueOrDefault())
+            var adjacentToId = filter.AdjacentTo.Value;
+            var targetItem = context.BaseItems.Where(e => e.Id == adjacentToId).Select(e => new { e.SortName, e.Id }).FirstOrDefault();
+            if (targetItem is not null)
             {
-                baseQuery = baseQuery
-                    .Where(e => e.Extras != null && e.Extras.Count > 0);
-            }
-            else
-            {
-                baseQuery = baseQuery
-                    .Where(e => e.Extras == null || e.Extras.Count == 0);
+                var targetSortName = targetItem.SortName ?? string.Empty;
+                var prevId = context.BaseItems
+                    .Where(e => string.Compare(e.SortName, targetSortName) < 0)
+                    .OrderByDescending(e => e.SortName)
+                    .Select(e => e.Id)
+                    .FirstOrDefault();
+
+                var nextId = context.BaseItems
+                    .Where(e => string.Compare(e.SortName, targetSortName) > 0)
+                    .OrderBy(e => e.SortName)
+                    .Select(e => e.Id)
+                    .FirstOrDefault();
+
+                var adjacentIds = new List<Guid> { adjacentToId };
+                if (prevId != Guid.Empty)
+                {
+                    adjacentIds.Add(prevId);
+                }
+
+                if (nextId != Guid.Empty)
+                {
+                    adjacentIds.Add(nextId);
+                }
+
+                baseQuery = baseQuery.Where(e => adjacentIds.Contains(e.Id));
             }
         }
 
@@ -2637,49 +3543,215 @@ public sealed class BaseItemRepository
 
         if (recursive)
         {
-            var folderList = TraverseHirachyDown(id, dbContext, item => (item.IsFolder || item.IsVirtualItem));
+            var descendantIds = _descendantQueryProvider.GetAllDescendantIds(dbContext, id);
 
             return dbContext.BaseItems
-                    .Where(e => folderList.Contains(e.ParentId!.Value) && !e.IsFolder && !e.IsVirtualItem)
+                    .Where(e => descendantIds.Contains(e.Id) && !e.IsFolder && !e.IsVirtualItem)
                     .All(f => f.UserData!.Any(e => e.UserId == user.Id && e.Played));
         }
 
         return dbContext.BaseItems.Where(e => e.ParentId == id).All(f => f.UserData!.Any(e => e.UserId == user.Id && e.Played));
     }
 
-    private static HashSet<Guid> TraverseHirachyDown(Guid parentId, JellyfinDbContext dbContext, Expression<Func<BaseItemEntity, bool>>? filter = null)
+    /// <inheritdoc/>
+    public int GetPlayedCount(InternalItemsQuery filter, Guid ancestorId)
     {
-        var folderStack = new HashSet<Guid>()
-            {
-                parentId
-            };
-        var folderList = new HashSet<Guid>()
-            {
-                parentId
-            };
+        ArgumentNullException.ThrowIfNull(filter.User);
+        using var dbContext = _dbProvider.CreateDbContext();
+
+        var baseQuery = BuildAccessFilteredDescendantsQuery(dbContext, filter, ancestorId);
+        return baseQuery.Count(b => b.UserData!.Any(u => u.UserId == filter.User.Id && u.Played));
+    }
+
+    /// <inheritdoc/>
+    public int GetTotalCount(InternalItemsQuery filter, Guid ancestorId)
+    {
+        using var dbContext = _dbProvider.CreateDbContext();
+
+        var baseQuery = BuildAccessFilteredDescendantsQuery(dbContext, filter, ancestorId);
+        return baseQuery.Count();
+    }
+
+    /// <inheritdoc/>
+    public (int Played, int Total) GetPlayedAndTotalCount(InternalItemsQuery filter, Guid ancestorId)
+    {
+        ArgumentNullException.ThrowIfNull(filter);
+        ArgumentNullException.ThrowIfNull(filter.User);
+        using var dbContext = _dbProvider.CreateDbContext();
 
-        while (folderStack.Count != 0)
+        var baseQuery = BuildAccessFilteredDescendantsQuery(dbContext, filter, ancestorId);
+        return GetPlayedAndTotalCountFromQuery(baseQuery, filter.User.Id);
+    }
+
+    /// <inheritdoc/>
+    public (int Played, int Total) GetPlayedAndTotalCountFromLinkedChildren(InternalItemsQuery filter, Guid parentId)
+    {
+        ArgumentNullException.ThrowIfNull(filter);
+        ArgumentNullException.ThrowIfNull(filter.User);
+        using var dbContext = _dbProvider.CreateDbContext();
+
+        var allDescendantIds = _descendantQueryProvider.GetAllDescendantIds(dbContext, parentId);
+        var baseQuery = dbContext.BaseItems
+            .Where(b => allDescendantIds.Contains(b.Id) && !b.IsFolder && !b.IsVirtualItem);
+        baseQuery = ApplyAccessFiltering(dbContext, baseQuery, filter);
+
+        return GetPlayedAndTotalCountFromQuery(baseQuery, filter.User.Id);
+    }
+
+    /// <inheritdoc/>
+    public IReadOnlyList<Guid> GetLinkedChildrenIds(Guid parentId, int? childType = null)
+    {
+        using var dbContext = _dbProvider.CreateDbContext();
+
+        var query = dbContext.LinkedChildren
+            .Where(lc => lc.ParentId.Equals(parentId));
+
+        if (childType.HasValue)
         {
-            var items = folderStack.ToArray();
-            folderStack.Clear();
-            var query = dbContext.BaseItems
-                .WhereOneOrMany(items, e => e.ParentId!.Value);
+            query = query.Where(lc => (int)lc.ChildType == childType.Value);
+        }
 
-            if (filter != null)
-            {
-                query = query.Where(filter);
-            }
+        return query
+            .Select(lc => lc.ChildId)
+            .ToList();
+    }
 
-            foreach (var item in query.Select(e => e.Id).ToArray())
+    private static (int Played, int Total) GetPlayedAndTotalCountFromQuery(IQueryable<BaseItemEntity> query, Guid userId)
+    {
+        var result = query
+            .Select(b => b.UserData!.Any(u => u.UserId == userId && u.Played))
+            .GroupBy(_ => 1)
+            .Select(g => new
             {
-                if (folderList.Add(item))
-                {
-                    folderStack.Add(item);
-                }
-            }
+                Total = g.Count(),
+                Played = g.Count(isPlayed => isPlayed)
+            })
+            .FirstOrDefault();
+
+        return result is null ? (0, 0) : (result.Played, result.Total);
+    }
+
+    /// <inheritdoc/>
+    public Dictionary<Guid, int> GetChildCountBatch(IReadOnlyList<Guid> parentIds, Guid? userId)
+    {
+        ArgumentNullException.ThrowIfNull(parentIds);
+
+        if (parentIds.Count == 0)
+        {
+            return new Dictionary<Guid, int>();
+        }
+
+        using var dbContext = _dbProvider.CreateDbContext();
+
+        // Convert to array for EF Core Contains support
+        var parentIdsArray = parentIds.ToArray();
+
+        // Count hierarchical children (immediate children via ParentId)
+        var hierarchicalCounts = dbContext.BaseItems
+            .Where(b => b.ParentId.HasValue && parentIdsArray.Contains(b.ParentId.Value))
+            .GroupBy(b => b.ParentId!.Value)
+            .Select(g => new { ParentId = g.Key, Count = g.Count() })
+            .ToDictionary(x => x.ParentId, x => x.Count);
+
+        // Count linked children (BoxSets, Playlists, etc.)
+        var linkedCounts = dbContext.LinkedChildren
+            .Where(lc => parentIdsArray.Contains(lc.ParentId))
+            .GroupBy(lc => lc.ParentId)
+            .Select(g => new { ParentId = g.Key, Count = g.Count() })
+            .ToDictionary(x => x.ParentId, x => x.Count);
+
+        // Merge results
+        var result = new Dictionary<Guid, int>();
+        foreach (var parentId in parentIds)
+        {
+            var hierarchicalCount = hierarchicalCounts.GetValueOrDefault(parentId, 0);
+            var linkedCount = linkedCounts.GetValueOrDefault(parentId, 0);
+
+            // If there are linked children, use that count (matches Folder.GetChildCount logic)
+            // Otherwise use hierarchical count
+            result[parentId] = linkedCount > 0 ? linkedCount : hierarchicalCount;
+        }
+
+        return result;
+    }
+
+    /// <summary>
+    /// Builds a query for descendants of an ancestor with user access filtering applied.
+    /// Uses recursive CTE to traverse both hierarchical (AncestorIds) and linked (LinkedChildren) relationships.
+    /// </summary>
+    private IQueryable<BaseItemEntity> BuildAccessFilteredDescendantsQuery(
+        JellyfinDbContext context,
+        InternalItemsQuery filter,
+        Guid ancestorId)
+    {
+        // Use recursive CTE to get all descendants (hierarchical and linked)
+        var allDescendantIds = _descendantQueryProvider.GetAllDescendantIds(context, ancestorId);
+
+        var baseQuery = context.BaseItems
+            .Where(b => allDescendantIds.Contains(b.Id) && !b.IsFolder && !b.IsVirtualItem);
+
+        return ApplyAccessFiltering(context, baseQuery, filter);
+    }
+
+    /// <summary>
+    /// Applies user access filtering to a query.
+    /// Includes TopParentIds, parental rating, and tag filtering.
+    /// </summary>
+    private IQueryable<BaseItemEntity> ApplyAccessFiltering(
+        JellyfinDbContext context,
+        IQueryable<BaseItemEntity> baseQuery,
+        InternalItemsQuery filter)
+    {
+        // Apply TopParentIds filtering (library folder access)
+        if (filter.TopParentIds.Length > 0)
+        {
+            var topParentIds = filter.TopParentIds;
+            baseQuery = baseQuery.Where(e => topParentIds.Contains(e.TopParentId!.Value));
         }
 
-        return folderList;
+        // Apply parental rating filtering
+        if (filter.MaxParentalRating is not null)
+        {
+            var maxScore = filter.MaxParentalRating.Score;
+            var maxSubScore = filter.MaxParentalRating.SubScore ?? 0;
+
+            baseQuery = baseQuery.Where(e =>
+                e.InheritedParentalRatingValue == null ||
+                e.InheritedParentalRatingValue < maxScore ||
+                (e.InheritedParentalRatingValue == maxScore && (e.InheritedParentalRatingSubValue ?? 0) <= maxSubScore));
+        }
+
+        // Apply block unrated items filtering
+        if (filter.BlockUnratedItems.Length > 0)
+        {
+            var unratedItemTypes = filter.BlockUnratedItems.Select(f => f.ToString()).ToArray();
+            baseQuery = baseQuery.Where(e =>
+                e.InheritedParentalRatingValue != null || !unratedItemTypes.Contains(e.UnratedType));
+        }
+
+        // Apply excluded tags filtering (blocked tags)
+        if (filter.ExcludeInheritedTags.Length > 0)
+        {
+            var excludedTags = filter.ExcludeInheritedTags;
+            baseQuery = baseQuery.Where(e =>
+                !context.ItemValuesMap.Any(f =>
+                    f.ItemValue.Type == ItemValueType.Tags
+                    && excludedTags.Contains(f.ItemValue.CleanValue)
+                    && (f.ItemId == e.Id || (e.SeriesId.HasValue && f.ItemId == e.SeriesId.Value))));
+        }
+
+        // Apply included tags filtering (allowed tags - item must have at least one)
+        if (filter.IncludeInheritedTags.Length > 0)
+        {
+            var includeTags = filter.IncludeInheritedTags;
+            baseQuery = baseQuery.Where(e =>
+                context.ItemValuesMap.Any(f =>
+                    f.ItemValue.Type == ItemValueType.Tags
+                    && includeTags.Contains(f.ItemValue.CleanValue)
+                    && (f.ItemId == e.Id || (e.SeriesId.HasValue && f.ItemId == e.SeriesId.Value))));
+        }
+
+        return baseQuery;
     }
 
     /// <inheritdoc/>
diff --git a/MediaBrowser.Controller/Dto/IDtoService.cs b/MediaBrowser.Controller/Dto/IDtoService.cs
index f1d507fcbd..8dc6f0aa68 100644
--- a/MediaBrowser.Controller/Dto/IDtoService.cs
+++ b/MediaBrowser.Controller/Dto/IDtoService.cs
@@ -36,8 +36,9 @@ namespace MediaBrowser.Controller.Dto
         /// <param name="options">The options.</param>
         /// <param name="user">The user.</param>
         /// <param name="owner">The owner.</param>
+        /// <param name="skipVisibilityCheck">Skip redundant visibility check if items are already filtered.</param>
         /// <returns>The <see cref="IReadOnlyList{T}"/> of <see cref="BaseItemDto"/>.</returns>
-        IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null);
+        IReadOnlyList<BaseItemDto> GetBaseItemDtos(IReadOnlyList<BaseItem> items, DtoOptions options, User? user = null, BaseItem? owner = null, bool skipVisibilityCheck = false);
 
         /// <summary>
         /// Gets the item by name dto.
diff --git a/MediaBrowser.Controller/Entities/BaseItem.cs b/MediaBrowser.Controller/Entities/BaseItem.cs
index eb7daeb532..13af7a6178 100644
--- a/MediaBrowser.Controller/Entities/BaseItem.cs
+++ b/MediaBrowser.Controller/Entities/BaseItem.cs
@@ -1806,10 +1806,23 @@ namespace MediaBrowser.Controller.Entities
             return item;
         }
 
+#pragma warning disable CS0618 // Type or member is obsolete - fallback for legacy LinkedChild data
         private BaseItem FindLinkedChild(LinkedChild info)
         {
-            var path = info.Path;
+            // First try to find by ItemId (new preferred method)
+            if (info.ItemId.HasValue && !info.ItemId.Value.Equals(Guid.Empty))
+            {
+                var item = LibraryManager.GetItemById(info.ItemId.Value);
+                if (item is not null)
+                {
+                    return item;
+                }
 
+                Logger.LogWarning("Unable to find linked item by ItemId {0}", info.ItemId);
+            }
+
+            // Fall back to Path (legacy method)
+            var path = info.Path;
             if (!string.IsNullOrEmpty(path))
             {
                 path = FileSystem.MakeAbsolutePath(ContainingFolderPath, path);
@@ -1824,13 +1837,14 @@ namespace MediaBrowser.Controller.Entities
                 return itemByPath;
             }
 
+            // Fall back to LibraryItemId (legacy method)
             if (!string.IsNullOrEmpty(info.LibraryItemId))
             {
                 var item = LibraryManager.GetItemById(info.LibraryItemId);
 
                 if (item is null)
                 {
-                    Logger.LogWarning("Unable to find linked item at path {0}", info.Path);
+                    Logger.LogWarning("Unable to find linked item by LibraryItemId {0}", info.LibraryItemId);
                 }
 
                 return item;
@@ -1838,6 +1852,7 @@ namespace MediaBrowser.Controller.Entities
 
             return null;
         }
+#pragma warning restore CS0618
 
         /// <summary>
         /// Adds a studio to the item.
diff --git a/MediaBrowser.Controller/Entities/CollectionFolder.cs b/MediaBrowser.Controller/Entities/CollectionFolder.cs
index ca79e62454..cf615788ee 100644
--- a/MediaBrowser.Controller/Entities/CollectionFolder.cs
+++ b/MediaBrowser.Controller/Entities/CollectionFolder.cs
@@ -45,6 +45,11 @@ namespace MediaBrowser.Controller.Entities
         }
 
         /// <summary>
+        /// Event raised when library options are updated for any collection folder.
+        /// </summary>
+        public static event EventHandler<LibraryOptionsUpdatedEventArgs> LibraryOptionsUpdated;
+
+        /// <summary>
         /// Gets the display preferences id.
         /// </summary>
         /// <remarks>
@@ -168,6 +173,8 @@ namespace MediaBrowser.Controller.Entities
             }
 
             XmlSerializer.SerializeToFile(clone, GetLibraryOptionsPath(path));
+
+            LibraryOptionsUpdated?.Invoke(null, new LibraryOptionsUpdatedEventArgs(path, options));
         }
 
         public static void OnCollectionFolderChange()
diff --git a/MediaBrowser.Controller/Entities/Folder.cs b/MediaBrowser.Controller/Entities/Folder.cs
index d2a3290c47..6338e54292 100644
--- a/MediaBrowser.Controller/Entities/Folder.cs
+++ b/MediaBrowser.Controller/Entities/Folder.cs
@@ -59,6 +59,10 @@ namespace MediaBrowser.Controller.Entities
         /// <value><c>true</c> if this instance is root; otherwise, <c>false</c>.</value>
         public bool IsRoot { get; set; }
 
+        /// <summary>
+        /// Gets or sets the linked children.
+        /// </summary>
+        [JsonIgnore]
         public LinkedChild[] LinkedChildren { get; set; }
 
         [JsonIgnore]
@@ -455,6 +459,14 @@ namespace MediaBrowser.Controller.Entities
                 // If it's an AggregateFolder, don't remove
                 if (shouldRemove && itemsRemoved.Count > 0)
                 {
+                    // Build a set of paths that are alternate versions of valid children
+                    // These items should not be deleted - they're managed by their primary video
+                    var alternateVersionPaths = validChildren
+                        .OfType<Video>()
+                        .SelectMany(v => v.LocalAlternateVersions ?? [])
+                        .Where(p => !string.IsNullOrEmpty(p))
+                        .ToHashSet(StringComparer.OrdinalIgnoreCase);
+
                     foreach (var item in itemsRemoved)
                     {
                         if (!item.CanDelete())
@@ -463,6 +475,24 @@ namespace MediaBrowser.Controller.Entities
                             continue;
                         }
 
+                        // Skip items that are alternate versions of another video
+                        if (item is Video video)
+                        {
+                            // Check via PrimaryVersionId
+                            if (!string.IsNullOrEmpty(video.PrimaryVersionId))
+                            {
+                                Logger.LogDebug("Item is an alternate version (via PrimaryVersionId), skipping deletion: {Path}", item.Path ?? item.Name);
+                                continue;
+                            }
+
+                            // Check if path is in LocalAlternateVersions of any valid child
+                            if (!string.IsNullOrEmpty(item.Path) && alternateVersionPaths.Contains(item.Path))
+                            {
+                                Logger.LogDebug("Item path matches an alternate version, skipping deletion: {Path}", item.Path);
+                                continue;
+                            }
+                        }
+
                         if (item.IsFileProtocol)
                         {
                             Logger.LogDebug("Removed item: {Path}", item.Path);
@@ -806,104 +836,12 @@ namespace MediaBrowser.Controller.Entities
 
         private bool RequiresPostFiltering(InternalItemsQuery query)
         {
-            if (LinkedChildren.Length > 0)
-            {
-                if (this is not ICollectionFolder)
-                {
-                    Logger.LogDebug("{Type}: Query requires post-filtering due to LinkedChildren.", GetType().Name);
-                    return true;
-                }
-            }
-
-            // Filter by Video3DFormat
-            if (query.Is3D.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to Is3D");
-                return true;
-            }
-
-            if (query.HasOfficialRating.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasOfficialRating");
-                return true;
-            }
-
-            if (query.IsPlaceHolder.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to IsPlaceHolder");
-                return true;
-            }
-
-            if (query.HasSpecialFeature.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasSpecialFeature");
-                return true;
-            }
-
-            if (query.HasSubtitles.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasSubtitles");
-                return true;
-            }
-
-            if (query.HasTrailer.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasTrailer");
-                return true;
-            }
-
-            if (query.HasThemeSong.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasThemeSong");
-                return true;
-            }
-
-            if (query.HasThemeVideo.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to HasThemeVideo");
-                return true;
-            }
-
-            // Filter by VideoType
-            if (query.VideoTypes.Length > 0)
-            {
-                Logger.LogDebug("Query requires post-filtering due to VideoTypes");
-                return true;
-            }
-
             if (CollapseBoxSetItems(query, this, query.User, ConfigurationManager))
             {
                 Logger.LogDebug("Query requires post-filtering due to CollapseBoxSetItems");
                 return true;
             }
 
-            if (!query.AdjacentTo.IsNullOrEmpty())
-            {
-                Logger.LogDebug("Query requires post-filtering due to AdjacentTo");
-                return true;
-            }
-
-            if (query.SeriesStatuses.Length > 0)
-            {
-                Logger.LogDebug("Query requires post-filtering due to SeriesStatuses");
-                return true;
-            }
-
-            if (query.AiredDuringSeason.HasValue)
-            {
-                Logger.LogDebug("Query requires post-filtering due to AiredDuringSeason");
-                return true;
-            }
-
-            if (query.IsPlayed.HasValue)
-            {
-                if (query.IncludeItemTypes.Length == 1 && query.IncludeItemTypes.Contains(BaseItemKind.Series))
-                {
-                    Logger.LogDebug("Query requires post-filtering due to IsPlayed");
-                    return true;
-                }
-            }
-
             return false;
         }
 
@@ -1012,29 +950,6 @@ namespace MediaBrowser.Controller.Entities
                 items = CollapseBoxSetItemsIfNeeded(items, query, this, user, ConfigurationManager, CollectionManager);
             }
 
-#pragma warning disable CA1309
-            if (!string.IsNullOrEmpty(query.NameStartsWithOrGreater))
-            {
-                items = items.Where(i => string.Compare(query.NameStartsWithOrGreater, i.SortName, StringComparison.InvariantCultureIgnoreCase) < 1);
-            }
-
-            if (!string.IsNullOrEmpty(query.NameStartsWith))
-            {
-                items = items.Where(i => i.SortName.StartsWith(query.NameStartsWith, StringComparison.InvariantCultureIgnoreCase));
-            }
-
-            if (!string.IsNullOrEmpty(query.NameLessThan))
-            {
-                items = items.Where(i => string.Compare(query.NameLessThan, i.SortName, StringComparison.InvariantCultureIgnoreCase) == 1);
-            }
-#pragma warning restore CA1309
-
-            // This must be the last filter
-            if (!query.AdjacentTo.IsNullOrEmpty())
-            {
-                items = UserViewBuilder.FilterForAdjacency(items.ToList(), query.AdjacentTo.Value);
-            }
-
             var filteredItems = items as IReadOnlyList<BaseItem> ?? items.ToList();
             var result = UserViewBuilder.SortAndPage(filteredItems, null, query, LibraryManager);
 
@@ -1664,11 +1579,13 @@ namespace MediaBrowser.Controller.Entities
 
                             if (!string.IsNullOrEmpty(resolvedPath))
                             {
+#pragma warning disable CS0618 // Type or member is obsolete - shortcuts require Path for lazy ItemId resolution
                                 return new LinkedChild
                                 {
                                     Path = resolvedPath,
                                     Type = LinkedChildType.Shortcut
                                 };
+#pragma warning restore CS0618
                             }
 
                             Logger.LogError("Error resolving shortcut {0}", i.FullName);
@@ -1786,38 +1703,42 @@ namespace MediaBrowser.Controller.Entities
                 return;
             }
 
-            if (itemDto is not null && fields.ContainsField(ItemFields.RecursiveItemCount))
-            {
-                itemDto.RecursiveItemCount = GetRecursiveChildCount(user);
-            }
-
-            if (SupportsPlayedStatus)
+            if (SupportsPlayedStatus || (itemDto is not null && fields.ContainsField(ItemFields.RecursiveItemCount)))
             {
-                var unplayedQueryResult = GetItems(new InternalItemsQuery(user)
-                {
-                    Recursive = true,
-                    IsFolder = false,
-                    IsVirtualItem = false,
-                    EnableTotalRecordCount = true,
-                    Limit = 0,
-                    IsPlayed = false,
-                    DtoOptions = new DtoOptions(false)
-                    {
-                        EnableImages = false
-                    }
-                }).TotalRecordCount;
+                var query = new InternalItemsQuery(user);
+                LibraryManager.ConfigureUserAccess(query, user);
 
-                dto.UnplayedItemCount = unplayedQueryResult;
+                int playedCount;
+                int totalCount;
 
-                if (itemDto?.RecursiveItemCount > 0)
+                if (LinkedChildren.Length > 0)
                 {
-                    var unplayedPercentage = ((double)unplayedQueryResult / itemDto.RecursiveItemCount.Value) * 100;
-                    dto.PlayedPercentage = 100 - unplayedPercentage;
-                    dto.Played = dto.PlayedPercentage.Value >= 100;
+                    (playedCount, totalCount) = ItemRepository.GetPlayedAndTotalCountFromLinkedChildren(query, Id);
                 }
                 else
                 {
-                    dto.Played = (dto.UnplayedItemCount ?? 0) == 0;
+                    (playedCount, totalCount) = ItemRepository.GetPlayedAndTotalCount(query, Id);
+                }
+
+                if (itemDto is not null && fields.ContainsField(ItemFields.RecursiveItemCount))
+                {
+                    itemDto.RecursiveItemCount = totalCount;
+                }
+
+                if (SupportsPlayedStatus)
+                {
+                    var unplayedCount = totalCount - playedCount;
+                    dto.UnplayedItemCount = unplayedCount;
+
+                    if (totalCount > 0)
+                    {
+                        dto.PlayedPercentage = playedCount / (double)totalCount * 100;
+                        dto.Played = playedCount >= totalCount;
+                    }
+                    else
+                    {
+                        dto.Played = true;
+                    }
                 }
             }
         }
diff --git a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
index 24fe3bb32d..b36ea627d8 100644
--- a/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
+++ b/MediaBrowser.Controller/Entities/InternalItemsQuery.cs
@@ -33,6 +33,7 @@ namespace MediaBrowser.Controller.Entities
             ExcludeItemIds = Array.Empty<Guid>();
             ExcludeItemTypes = Array.Empty<BaseItemKind>();
             ExcludeTags = Array.Empty<string>();
+            ExtraTypes = Array.Empty<ExtraType>();
             GenreIds = Array.Empty<Guid>();
             Genres = Array.Empty<string>();
             GroupByPresentationUniqueKey = true;
@@ -44,6 +45,7 @@ namespace MediaBrowser.Controller.Entities
             MediaTypes = Array.Empty<MediaType>();
             OfficialRatings = Array.Empty<string>();
             OrderBy = Array.Empty<(ItemSortBy, SortOrder)>();
+            OwnerIds = Array.Empty<Guid>();
             PersonIds = Array.Empty<Guid>();
             PersonTypes = Array.Empty<string>();
             PresetViews = Array.Empty<CollectionType?>();
@@ -369,6 +371,8 @@ namespace MediaBrowser.Controller.Entities
 
         public bool SkipDeserialization { get; set; }
 
+        public bool IncludeExtras { get; set; }
+
         public void SetUser(User user)
         {
             var maxRating = user.MaxParentalRatingScore;
diff --git a/MediaBrowser.Controller/Entities/LinkedChild.cs b/MediaBrowser.Controller/Entities/LinkedChild.cs
index 98e4f525f5..a3aa9dd0c9 100644
--- a/MediaBrowser.Controller/Entities/LinkedChild.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChild.cs
@@ -3,7 +3,6 @@
 #pragma warning disable CS1591
 
 using System;
-using System.Globalization;
 
 namespace MediaBrowser.Controller.Entities
 {
@@ -13,10 +12,18 @@ namespace MediaBrowser.Controller.Entities
         {
         }
 
+        /// <summary>
+        /// Gets or sets the path.
+        /// </summary>
+        [Obsolete("Use ItemId instead")]
         public string Path { get; set; }
 
         public LinkedChildType Type { get; set; }
 
+        /// <summary>
+        /// Gets or sets the library item id.
+        /// </summary>
+        [Obsolete("Use ItemId instead")]
         public string LibraryItemId { get; set; }
 
         /// <summary>
@@ -28,18 +35,11 @@ namespace MediaBrowser.Controller.Entities
         {
             ArgumentNullException.ThrowIfNull(item);
 
-            var child = new LinkedChild
+            return new LinkedChild
             {
-                Path = item.Path,
+                ItemId = item.Id,
                 Type = LinkedChildType.Manual
             };
-
-            if (string.IsNullOrEmpty(child.Path))
-            {
-                child.LibraryItemId = item.Id.ToString("N", CultureInfo.InvariantCulture);
-            }
-
-            return child;
         }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChildComparer.cs b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
index 4f13ac61fe..8b611345f4 100644
--- a/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChildComparer.cs
@@ -19,17 +19,34 @@ namespace MediaBrowser.Controller.Entities
 
         public bool Equals(LinkedChild x, LinkedChild y)
         {
-            if (x.Type == y.Type)
+            if (x.Type != y.Type)
             {
-                return _fileSystem.AreEqual(x.Path, y.Path);
+                return false;
             }
 
-            return false;
+            // Compare by ItemId first (preferred)
+            if (x.ItemId.HasValue && y.ItemId.HasValue)
+            {
+                return x.ItemId.Value.Equals(y.ItemId.Value);
+            }
+
+#pragma warning disable CS0618 // Type or member is obsolete - fallback for shortcut/legacy comparison
+            // Fall back to Path comparison for shortcuts and legacy data
+            return _fileSystem.AreEqual(x.Path, y.Path);
+#pragma warning restore CS0618
         }
 
         public int GetHashCode(LinkedChild obj)
         {
+            // Use ItemId for hash if available, otherwise fall back to legacy fields
+            if (obj.ItemId.HasValue && !obj.ItemId.Value.Equals(Guid.Empty))
+            {
+                return HashCode.Combine(obj.ItemId.Value, obj.Type);
+            }
+
+#pragma warning disable CS0618 // Type or member is obsolete - fallback for shortcut/legacy hashing
             return ((obj.Path ?? string.Empty) + (obj.LibraryItemId ?? string.Empty) + obj.Type).GetHashCode(StringComparison.Ordinal);
+#pragma warning restore CS0618
         }
     }
 }
diff --git a/MediaBrowser.Controller/Entities/LinkedChildType.cs b/MediaBrowser.Controller/Entities/LinkedChildType.cs
index 3bd260a102..5ce66a561f 100644
--- a/MediaBrowser.Controller/Entities/LinkedChildType.cs
+++ b/MediaBrowser.Controller/Entities/LinkedChildType.cs
@@ -13,6 +13,16 @@ namespace MediaBrowser.Controller.Entities
         /// <summary>
         /// Shortcut linked child.
         /// </summary>
-        Shortcut = 1
+        Shortcut = 1,
+
+        /// <summary>
+        /// Local alternate version (same item, different file path).
+        /// </summary>
+        LocalAlternateVersion = 2,
+
+        /// <summary>
+        /// Linked alternate version (different item ID).
+        /// </summary>
+        LinkedAlternateVersion = 3
     }
 }
diff --git a/MediaBrowser.Controller/Entities/Movies/BoxSet.cs b/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
index 3999c3e076..c55a70a67b 100644
--- a/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
+++ b/MediaBrowser.Controller/Entities/Movies/BoxSet.cs
@@ -37,9 +37,7 @@ namespace MediaBrowser.Controller.Entities.Movies
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the display order.
diff --git a/MediaBrowser.Controller/Entities/Movies/Movie.cs b/MediaBrowser.Controller/Entities/Movies/Movie.cs
index 710b05e7f9..797f44e2d5 100644
--- a/MediaBrowser.Controller/Entities/Movies/Movie.cs
+++ b/MediaBrowser.Controller/Entities/Movies/Movie.cs
@@ -4,13 +4,13 @@
 
 using System;
 using System.Collections.Generic;
-using System.Globalization;
 using System.Linq;
 using System.Text.Json.Serialization;
+using System.Threading;
+using System.Threading.Tasks;
 using Jellyfin.Data.Enums;
 using MediaBrowser.Controller.Providers;
 using MediaBrowser.Model.Entities;
-using MediaBrowser.Model.Providers;
 
 namespace MediaBrowser.Controller.Entities.Movies
 {
@@ -28,9 +28,7 @@ namespace MediaBrowser.Controller.Entities.Movies
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the name of the TMDb collection.
@@ -85,6 +83,34 @@ namespace MediaBrowser.Controller.Entities.Movies
             return info;
         }
 
+        protected override async Task RefreshMetadataForVersions(MetadataRefreshOptions options, bool copyTitleMetadata, string path, CancellationToken cancellationToken)
+        {
+            var newOptions = new MetadataRefreshOptions(options)
+            {
+                SearchResult = null
+            };
+
+            var id = LibraryManager.GetNewItemId(path, typeof(Movie));
+            if (LibraryManager.GetItemById(id) is not Movie movie)
+            {
+                movie = LibraryManager.ResolvePath(FileSystem.GetFileSystemInfo(path)) as Movie;
+
+                newOptions.ForceSave = true;
+            }
+
+            if (movie is null)
+            {
+                return;
+            }
+
+            if (movie.OwnerId.Equals(Guid.Empty))
+            {
+                movie.OwnerId = Id;
+            }
+
+            await RefreshMetadataForOwnedItem(movie, copyTitleMetadata, newOptions, cancellationToken).ConfigureAwait(false);
+        }
+
         /// <inheritdoc />
         public override bool BeforeMetadataRefresh(bool replaceAllMetadata)
         {
diff --git a/MediaBrowser.Controller/Entities/TV/Episode.cs b/MediaBrowser.Controller/Entities/TV/Episode.cs
index 6bdba36f9c..dbe6f94dfd 100644
--- a/MediaBrowser.Controller/Entities/TV/Episode.cs
+++ b/MediaBrowser.Controller/Entities/TV/Episode.cs
@@ -28,9 +28,7 @@ namespace MediaBrowser.Controller.Entities.TV
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the season in which it aired.
diff --git a/MediaBrowser.Controller/Entities/TV/Series.cs b/MediaBrowser.Controller/Entities/TV/Series.cs
index 6396631f99..ca9ac3f047 100644
--- a/MediaBrowser.Controller/Entities/TV/Series.cs
+++ b/MediaBrowser.Controller/Entities/TV/Series.cs
@@ -52,9 +52,7 @@ namespace MediaBrowser.Controller.Entities.TV
 
         /// <inheritdoc />
         [JsonIgnore]
-        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras()
-            .Where(extra => extra.ExtraType == Model.Entities.ExtraType.Trailer)
-            .ToArray();
+        public IReadOnlyList<BaseItem> LocalTrailers => GetExtras([Model.Entities.ExtraType.Trailer]).ToArray();
 
         /// <summary>
         /// Gets or sets the display order.
diff --git a/MediaBrowser.Controller/Entities/UserViewBuilder.cs b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
index bed7554b19..47d732c745 100644
--- a/MediaBrowser.Controller/Entities/UserViewBuilder.cs
+++ b/MediaBrowser.Controller/Entities/UserViewBuilder.cs
@@ -16,9 +16,7 @@ using MediaBrowser.Controller.TV;
 using MediaBrowser.Model.Entities;
 using MediaBrowser.Model.Querying;
 using Microsoft.Extensions.Logging;
-using Episode = MediaBrowser.Controller.Entities.TV.Episode;
 using MetadataProvider = MediaBrowser.Model.Entities.MetadataProvider;
-using Series = MediaBrowser.Controller.Entities.TV.Series;
 
 namespace MediaBrowser.Controller.Entities
 {
@@ -140,7 +138,7 @@ namespace MediaBrowser.Controller.Entities
 
                 if (query.IncludeItemTypes.Length == 0)
                 {
-                    query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+                    query.IncludeItemTypes = [BaseItemKind.Movie];
                 }
 
                 return parent.QueryRecursive(query);
@@ -165,7 +163,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
             query.IsFavorite = true;
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -176,7 +174,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
             query.IsFavorite = true;
-            query.IncludeItemTypes = new[] { BaseItemKind.Series };
+            query.IncludeItemTypes = [BaseItemKind.Series];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -187,7 +185,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
             query.IsFavorite = true;
-            query.IncludeItemTypes = new[] { BaseItemKind.Episode };
+            query.IncludeItemTypes = [BaseItemKind.Episode];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -198,7 +196,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -206,7 +204,7 @@ namespace MediaBrowser.Controller.Entities
         private QueryResult<BaseItem> GetMovieCollections(User user, InternalItemsQuery query)
         {
             query.Parent = null;
-            query.IncludeItemTypes = new[] { BaseItemKind.BoxSet };
+            query.IncludeItemTypes = [BaseItemKind.BoxSet];
             query.SetUser(user);
             query.Recursive = true;
 
@@ -215,25 +213,25 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetMovieLatest(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return ConvertToResult(_libraryManager.GetItemList(query));
         }
 
         private QueryResult<BaseItem> GetMovieResume(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.IsResumable = true;
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return ConvertToResult(_libraryManager.GetItemList(query));
         }
@@ -247,7 +245,7 @@ namespace MediaBrowser.Controller.Entities
         {
             var genres = parent.QueryRecursive(new InternalItemsQuery(user)
             {
-                IncludeItemTypes = new[] { BaseItemKind.Movie },
+                IncludeItemTypes = [BaseItemKind.Movie],
                 Recursive = true,
                 EnableTotalRecordCount = false
             }).Items
@@ -275,10 +273,10 @@ namespace MediaBrowser.Controller.Entities
         {
             query.Recursive = true;
             query.Parent = queryParent;
-            query.GenreIds = new[] { displayParent.Id };
+            query.GenreIds = [displayParent.Id];
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Movie };
+            query.IncludeItemTypes = [BaseItemKind.Movie];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -292,12 +290,12 @@ namespace MediaBrowser.Controller.Entities
 
                 if (query.IncludeItemTypes.Length == 0)
                 {
-                    query.IncludeItemTypes = new[]
-                    {
+                    query.IncludeItemTypes =
+                    [
                         BaseItemKind.Series,
                         BaseItemKind.Season,
                         BaseItemKind.Episode
-                    };
+                    ];
                 }
 
                 return parent.QueryRecursive(query);
@@ -319,12 +317,12 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvLatest(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DateCreated, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Episode };
+            query.IncludeItemTypes = [BaseItemKind.Episode];
             query.IsVirtualItem = false;
 
             return ConvertToResult(_libraryManager.GetItemList(query));
@@ -332,7 +330,7 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvNextUp(Folder parent, InternalItemsQuery query)
         {
-            var parentFolders = GetMediaFolders(parent, query.User, new[] { CollectionType.tvshows });
+            var parentFolders = GetMediaFolders(parent, query.User, [CollectionType.tvshows]);
 
             var result = _tvSeriesManager.GetNextUp(
                 new NextUpQuery
@@ -349,13 +347,13 @@ namespace MediaBrowser.Controller.Entities
 
         private QueryResult<BaseItem> GetTvResume(Folder parent, User user, InternalItemsQuery query)
         {
-            query.OrderBy = new[] { (ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending) };
+            query.OrderBy = [(ItemSortBy.DatePlayed, SortOrder.Descending), (ItemSortBy.SortName, SortOrder.Descending)];
             query.IsResumable = true;
             query.Recursive = true;
             query.Parent = parent;
             query.SetUser(user);
             query.Limit = GetSpecialItemsLimit();
-            query.IncludeItemTypes = new[] { BaseItemKind.Episode };
+            query.IncludeItemTypes = [BaseItemKind.Episode];
 
             return ConvertToResult(_libraryManager.GetItemList(query));
         }
@@ -366,7 +364,7 @@ namespace MediaBrowser.Controller.Entities
             query.Parent = parent;
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Series };
+            query.IncludeItemTypes = [BaseItemKind.Series];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -375,7 +373,7 @@ namespace MediaBrowser.Controller.Entities
         {
             var genres = parent.QueryRecursive(new InternalItemsQuery(user)
             {
-                IncludeItemTypes = new[] { BaseItemKind.Series },
+                IncludeItemTypes = [BaseItemKind.Series],
                 Recursive = true,
                 EnableTotalRecordCount = false
             }).Items
@@ -403,10 +401,10 @@ namespace MediaBrowser.Controller.Entities
         {
             query.Recursive = true;
             query.Parent = queryParent;
-            query.GenreIds = new[] { displayParent.Id };
+            query.GenreIds = [displayParent.Id];
             query.SetUser(user);
 
-            query.IncludeItemTypes = new[] { BaseItemKind.Series };
+            query.IncludeItemTypes = [BaseItemKind.Series];
 
             return _libraryManager.GetItemsResult(query);
         }
@@ -418,7 +416,7 @@ namespace MediaBrowser.Controller.Entities
         {
             items = items.Where(i => Filter(i, query.User, query, _userDataManager, _libraryManager));
 
-            return PostFilterAndSort(items, null, query, _libraryManager);
+            return SortAndPage(items, null, query, _libraryManager);
         }
 
         public static bool FilterItem(BaseItem item, InternalItemsQuery query)
@@ -426,21 +424,6 @@ namespace MediaBrowser.Controller.Entities
             return Filter(item, query.User, query, BaseItem.UserDataManager, BaseItem.LibraryManager);
         }
 
-        public static QueryResult<BaseItem> PostFilterAndSort(
-            IEnumerable<BaseItem> items,
-            int? totalRecordLimit,
-            InternalItemsQuery query,
-            ILibraryManager libraryManager)
-        {
-            // This must be the last filter
-            if (!query.AdjacentTo.IsNullOrEmpty())
-            {
-                items = FilterForAdjacency(items.ToList(), query.AdjacentTo.Value);
-            }
-
-            return SortAndPage(items, totalRecordLimit, query, libraryManager);
-        }
-
         public static QueryResult<BaseItem> SortAndPage(
             IEnumerable<BaseItem> items,
             int? totalRecordLimit,
@@ -556,38 +539,6 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.IsPlayed.HasValue)
-            {
-                userData ??= userDataManager.GetUserData(user, item);
-                if (item.IsPlayed(user, userData) != query.IsPlayed.Value)
-                {
-                    return false;
-                }
-            }
-
-            // Filter by Video3DFormat
-            if (query.Is3D.HasValue)
-            {
-                var val = query.Is3D.Value;
-                var video = item as Video;
-
-                if (video is null || val != video.Video3DFormat.HasValue)
-                {
-                    return false;
-                }
-            }
-
-            /*
-             * fuck - fix this
-            if (query.IsHD.HasValue)
-            {
-                if (item.IsHD != query.IsHD.Value)
-                {
-                    return false;
-                }
-            }
-            */
-
             if (query.IsLocked.HasValue)
             {
                 var val = query.IsLocked.Value;
@@ -645,68 +596,6 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.HasOfficialRating.HasValue)
-            {
-                var filterValue = query.HasOfficialRating.Value;
-
-                var hasValue = !string.IsNullOrEmpty(item.OfficialRating);
-
-                if (hasValue != filterValue)
-                {
-                    return false;
-                }
-            }
-
-            if (query.IsPlaceHolder.HasValue)
-            {
-                var filterValue = query.IsPlaceHolder.Value;
-
-                var isPlaceHolder = false;
-
-                if (item is ISupportsPlaceHolders hasPlaceHolder)
-                {
-                    isPlaceHolder = hasPlaceHolder.IsPlaceHolder;
-                }
-
-                if (isPlaceHolder != filterValue)
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasSpecialFeature.HasValue)
-            {
-                var filterValue = query.HasSpecialFeature.Value;
-
-                if (item is IHasSpecialFeatures movie)
-                {
-                    var ok = filterValue
-                        ? movie.SpecialFeatureIds.Count > 0
-                        : movie.SpecialFeatureIds.Count == 0;
-
-                    if (!ok)
-                    {
-                        return false;
-                    }
-                }
-                else
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasSubtitles.HasValue)
-            {
-                var val = query.HasSubtitles.Value;
-
-                var video = item as Video;
-
-                if (video is null || val != video.HasSubtitles)
-                {
-                    return false;
-                }
-            }
-
             if (query.HasParentalRating.HasValue)
             {
                 var val = query.HasParentalRating.Value;
@@ -734,66 +623,12 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.HasTrailer.HasValue)
-            {
-                var val = query.HasTrailer.Value;
-                var trailerCount = 0;
-
-                if (item is IHasTrailers hasTrailers)
-                {
-                    trailerCount = hasTrailers.GetTrailerCount();
-                }
-
-                var ok = val ? trailerCount > 0 : trailerCount == 0;
-
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasThemeSong.HasValue)
-            {
-                var filterValue = query.HasThemeSong.Value;
-
-                var themeCount = item.GetThemeSongs(user).Count;
-                var ok = filterValue ? themeCount > 0 : themeCount == 0;
-
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
-            if (query.HasThemeVideo.HasValue)
-            {
-                var filterValue = query.HasThemeVideo.Value;
-
-                var themeCount = item.GetThemeVideos(user).Count;
-                var ok = filterValue ? themeCount > 0 : themeCount == 0;
-
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
             // Apply genre filter
             if (query.Genres.Count > 0 && !query.Genres.Any(v => item.Genres.Contains(v, StringComparison.OrdinalIgnoreCase)))
             {
                 return false;
             }
 
-            // Filter by VideoType
-            if (query.VideoTypes.Length > 0)
-            {
-                var video = item as Video;
-                if (video is null || !query.VideoTypes.Contains(video.VideoType))
-                {
-                    return false;
-                }
-            }
-
             if (query.ImageTypes.Length > 0 && !query.ImageTypes.Any(item.HasImage))
             {
                 return false;
@@ -912,30 +747,6 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            if (query.SeriesStatuses.Length > 0)
-            {
-                var ok = new[] { item }.OfType<Series>().Any(p => p.Status.HasValue && query.SeriesStatuses.Contains(p.Status.Value));
-                if (!ok)
-                {
-                    return false;
-                }
-            }
-
-            if (query.AiredDuringSeason.HasValue)
-            {
-                var episode = item as Episode;
-
-                if (episode is null)
-                {
-                    return false;
-                }
-
-                if (!Series.FilterEpisodesBySeason(new[] { episode }, query.AiredDuringSeason.Value, true).Any())
-                {
-                    return false;
-                }
-            }
-
             if (query.ExcludeItemIds.Contains(item.Id))
             {
                 return false;
@@ -989,7 +800,7 @@ namespace MediaBrowser.Controller.Entities
                 return GetMediaFolders(user, viewTypes);
             }
 
-            return new BaseItem[] { parent };
+            return [parent];
         }
 
         private UserView GetUserViewWithName(CollectionType? type, string sortName, BaseItem parent)
diff --git a/MediaBrowser.Controller/Entities/Video.cs b/MediaBrowser.Controller/Entities/Video.cs
index 1043029c6e..1ddc193359 100644
--- a/MediaBrowser.Controller/Entities/Video.cs
+++ b/MediaBrowser.Controller/Entities/Video.cs
@@ -160,7 +160,7 @@ namespace MediaBrowser.Controller.Entities
         public bool IsStacked => AdditionalParts.Length > 0;
 
         [JsonIgnore]
-        public override bool HasLocalAlternateVersions => LocalAlternateVersions.Length > 0;
+        public override bool HasLocalAlternateVersions => LibraryManager.GetLocalAlternateVersionIds(this).Any();
 
         public static IRecordingsManager RecordingsManager { get; set; }
 
@@ -260,7 +260,10 @@ namespace MediaBrowser.Controller.Entities
                 {
                     if (callstack.Contains(video.Id))
                     {
-                        return video.LinkedAlternateVersions.Length + video.LocalAlternateVersions.Length + 1;
+                        // Count alternate versions using LibraryManager
+                        var linkedCount = LibraryManager.GetLinkedAlternateVersions(video).Count();
+                        var localCount = LibraryManager.GetLocalAlternateVersionIds(video).Count();
+                        return linkedCount + localCount + 1;
                     }
 
                     callstack.Add(video.Id);
@@ -268,7 +271,10 @@ namespace MediaBrowser.Controller.Entities
                 }
             }
 
-            return LinkedAlternateVersions.Length + LocalAlternateVersions.Length + 1;
+            // Count alternate versions using LibraryManager
+            var linkedVersionCount = LibraryManager.GetLinkedAlternateVersions(this).Count();
+            var localVersionCount = LibraryManager.GetLocalAlternateVersionIds(this).Count();
+            return linkedVersionCount + localVersionCount + 1;
         }
 
         public override List<string> GetUserDataKeys()
@@ -364,11 +370,6 @@ namespace MediaBrowser.Controller.Entities
             return AdditionalParts.Select(i => LibraryManager.GetNewItemId(i, typeof(Video)));
         }
 
-        public IEnumerable<Guid> GetLocalAlternateVersionIds()
-        {
-            return LocalAlternateVersions.Select(i => LibraryManager.GetNewItemId(i, typeof(Video)));
-        }
-
         private string GetUserDataKey(string providerId)
         {
             var key = providerId + "-" + ExtraType.ToString().ToLowerInvariant();
@@ -382,15 +383,6 @@ namespace MediaBrowser.Controller.Entities
             return key;
         }
 
-        public IEnumerable<Video> GetLinkedAlternateVersions()
-        {
-            return LinkedAlternateVersions
-                .Select(GetLinkedChild)
-                .Where(i => i is not null)
-                .OfType<Video>()
-                .OrderBy(i => i.SortName);
-        }
-
         /// <summary>
         /// Gets the additional parts.
         /// </summary>
@@ -454,7 +446,7 @@ namespace MediaBrowser.Controller.Entities
                     RefreshLinkedAlternateVersions();
 
                     var tasks = LocalAlternateVersions
-                        .Select(i => RefreshMetadataForOwnedVideo(options, false, i, cancellationToken));
+                        .Select(i => RefreshMetadataForVersions(options, false, i, cancellationToken));
 
                     await Task.WhenAll(tasks).ConfigureAwait(false);
                 }
@@ -463,6 +455,39 @@ namespace MediaBrowser.Controller.Entities
             return hasChanges;
         }
 
+        protected virtual async Task RefreshMetadataForVersions(MetadataRefreshOptions options, bool copyTitleMetadata, string path, CancellationToken cancellationToken)
+        {
+            await RefreshMetadataForOwnedVideo(options, copyTitleMetadata, path, cancellationToken).ConfigureAwait(false);
+        }
+
+        private new async Task RefreshMetadataForOwnedVideo(MetadataRefreshOptions options, bool copyTitleMetadata, string path, CancellationToken cancellationToken)
+        {
+            var newOptions = new MetadataRefreshOptions(options)
+            {
+                SearchResult = null
+            };
+
+            var id = LibraryManager.GetNewItemId(path, typeof(Video));
+            if (LibraryManager.GetItemById(id) is not Video video)
+            {
+                video = LibraryManager.ResolvePath(FileSystem.GetFileSystemInfo(path)) as Video;
+
+                newOptions.ForceSave = true;
+            }
+
+            if (video is null)
+            {
+                return;
+            }
+
+            if (video.OwnerId.IsEmpty())
+            {
+                video.OwnerId = Id;
+            }
+
+            await RefreshMetadataForOwnedItem(video, copyTitleMetadata, newOptions, cancellationToken).ConfigureAwait(false);
+        }
+
         private void RefreshLinkedAlternateVersions()
         {
             foreach (var child in LinkedAlternateVersions)
@@ -480,7 +505,7 @@ namespace MediaBrowser.Controller.Entities
         {
             await base.UpdateToRepositoryAsync(updateReason, cancellationToken).ConfigureAwait(false);
 
-            var localAlternates = GetLocalAlternateVersionIds()
+            var localAlternates = LibraryManager.GetLocalAlternateVersionIds(this)
                 .Select(i => LibraryManager.GetItemById(i))
                 .Where(i => i is not null);
 
@@ -537,7 +562,7 @@ namespace MediaBrowser.Controller.Entities
                 (this, MediaSourceType.Default)
             };
 
-            list.AddRange(GetLinkedAlternateVersions().Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
+            list.AddRange(LibraryManager.GetLinkedAlternateVersions(this).Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
 
             if (!string.IsNullOrEmpty(PrimaryVersionId))
             {
@@ -545,14 +570,14 @@ namespace MediaBrowser.Controller.Entities
                 {
                     var existingIds = list.Select(i => i.Item1.Id).ToList();
                     list.Add((primary, MediaSourceType.Grouping));
-                    list.AddRange(primary.GetLinkedAlternateVersions().Where(i => !existingIds.Contains(i.Id)).Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
+                    list.AddRange(LibraryManager.GetLinkedAlternateVersions(primary).Where(i => !existingIds.Contains(i.Id)).Select(i => ((BaseItem)i, MediaSourceType.Grouping)));
                 }
             }
 
             var localAlternates = list
                 .SelectMany(i =>
                 {
-                    return i.Item1 is Video video ? video.GetLocalAlternateVersionIds() : Enumerable.Empty<Guid>();
+                    return i.Item1 is Video video ? LibraryManager.GetLocalAlternateVersionIds(video) : Enumerable.Empty<Guid>();
                 })
                 .Select(LibraryManager.GetItemById)
                 .Where(i => i is not null)
diff --git a/MediaBrowser.Controller/Library/ILibraryManager.cs b/MediaBrowser.Controller/Library/ILibraryManager.cs
index df1c98f3f7..c19d15d85f 100644
--- a/MediaBrowser.Controller/Library/ILibraryManager.cs
+++ b/MediaBrowser.Controller/Library/ILibraryManager.cs
@@ -214,6 +214,22 @@ namespace MediaBrowser.Controller.Library
         Task<IEnumerable<Video>> GetIntros(BaseItem item, User user);
 
         /// <summary>
+        /// Gets the IDs of local alternate versions for a video.
+        /// Local alternate versions are alternate quality versions at different file paths.
+        /// </summary>
+        /// <param name="video">The video item.</param>
+        /// <returns>Enumerable of alternate version item IDs.</returns>
+        IEnumerable<Guid> GetLocalAlternateVersionIds(Video video);
+
+        /// <summary>
+        /// Gets the linked alternate versions for a video.
+        /// Linked alternate versions are different items representing the same content (e.g., Director's Cut).
+        /// </summary>
+        /// <param name="video">The video item.</param>
+        /// <returns>Enumerable of linked Video items.</returns>
+        IEnumerable<Video> GetLinkedAlternateVersions(Video video);
+
+        /// <summary>
         /// Adds the parts.
         /// </summary>
         /// <param name="rules">The rules.</param>
@@ -601,6 +617,20 @@ namespace MediaBrowser.Controller.Library
         IReadOnlyList<string> GetNextUpSeriesKeys(InternalItemsQuery query, IReadOnlyCollection<BaseItem> parents, DateTime dateCutoff);
 
         /// <summary>
+        /// Gets next up episodes for multiple series in a single batched query.
+        /// </summary>
+        /// <param name="query">The query filter.</param>
+        /// <param name="seriesKeys">The series presentation unique keys to query.</param>
+        /// <param name="includeSpecials">Whether to include specials for aired episode order sorting.</param>
+        /// <param name="includeWatchedForRewatching">Whether to include watched episodes for rewatching mode.</param>
+        /// <returns>A dictionary mapping series key to batch result.</returns>
+        IReadOnlyDictionary<string, MediaBrowser.Controller.Persistence.NextUpEpisodeBatchResult> GetNextUpEpisodesBatch(
+            InternalItemsQuery query,
+            IReadOnlyList<string> seriesKeys,
+            bool includeSpecials,
+            bool includeWatchedForRewatching);
+
+        /// <summary>
         /// Gets the items result.
         /// </summary>
         /// <param name="query">The query.</param>
@@ -649,6 +679,23 @@ namespace MediaBrowser.Controller.Library
 
         ItemCounts GetItemCounts(InternalItemsQuery query);
 
+        /// <summary>
+        /// Batch-fetches child counts for multiple parent folders.
+        /// Returns the count of immediate children (non-recursive) for each parent.
+        /// </summary>
+        /// <param name="parentIds">The list of parent folder IDs.</param>
+        /// <param name="userId">The user ID for access filtering.</param>
+        /// <returns>Dictionary mapping parent ID to child count.</returns>
+        Dictionary<Guid, int> GetChildCountBatch(IReadOnlyList<Guid> parentIds, Guid? userId);
+
+        /// <summary>
+        /// Configures the query with user access settings including TopParentIds for library access.
+        /// Call this before passing a query to methods that need user access filtering.
+        /// </summary>
+        /// <param name="query">The query to configure.</param>
+        /// <param name="user">The user to configure access for.</param>
+        void ConfigureUserAccess(InternalItemsQuery query, User user);
+
         Task RunMetadataSavers(BaseItem item, ItemUpdateType updateReason);
 
         BaseItem GetParentItem(Guid? parentId, Guid? userId);
diff --git a/MediaBrowser.Controller/Persistence/IItemRepository.cs b/MediaBrowser.Controller/Persistence/IItemRepository.cs
index bf80b7d0a8..f7ed39730e 100644
--- a/MediaBrowser.Controller/Persistence/IItemRepository.cs
+++ b/MediaBrowser.Controller/Persistence/IItemRepository.cs
@@ -88,6 +88,21 @@ public interface IItemRepository
     IReadOnlyList<string> GetNextUpSeriesKeys(InternalItemsQuery filter, DateTime dateCutoff);
 
     /// <summary>
+    /// Gets next up episodes for multiple series in a single batched query.
+    /// Returns the last watched episode, next unwatched episode, specials, and next played episode for each series.
+    /// </summary>
+    /// <param name="filter">The query filter.</param>
+    /// <param name="seriesKeys">The series presentation unique keys to query.</param>
+    /// <param name="includeSpecials">Whether to include specials (ParentIndexNumber = 0) in the results.</param>
+    /// <param name="includeWatchedForRewatching">Whether to include watched episodes for rewatching mode.</param>
+    /// <returns>A dictionary mapping series key to batch result containing episodes needed for NextUp calculation.</returns>
+    IReadOnlyDictionary<string, NextUpEpisodeBatchResult> GetNextUpEpisodesBatch(
+        InternalItemsQuery filter,
+        IReadOnlyList<string> seriesKeys,
+        bool includeSpecials,
+        bool includeWatchedForRewatching);
+
+    /// <summary>
     /// Updates the inherited values.
     /// </summary>
     void UpdateInheritedValues();
@@ -133,9 +148,66 @@ public interface IItemRepository
     bool GetIsPlayed(User user, Guid id, bool recursive);
 
     /// <summary>
+    /// Gets the count of played items that are descendants of the specified ancestor.
+    /// Uses the AncestorIds table for efficient recursive lookup.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="ancestorId">The ancestor item id.</param>
+    /// <returns>The count of played descendant items.</returns>
+    int GetPlayedCount(InternalItemsQuery filter, Guid ancestorId);
+
+    /// <summary>
+    /// Gets the total count of items that are descendants of the specified ancestor.
+    /// Uses the AncestorIds table for efficient recursive lookup.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="ancestorId">The ancestor item id.</param>
+    /// <returns>The total count of descendant items.</returns>
+    int GetTotalCount(InternalItemsQuery filter, Guid ancestorId);
+
+    /// <summary>
+    /// Gets both the played count and total count of items that are descendants of the specified ancestor.
+    /// Uses the AncestorIds table for efficient recursive lookup.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="ancestorId">The ancestor item id.</param>
+    /// <returns>A tuple containing (Played count, Total count).</returns>
+    (int Played, int Total) GetPlayedAndTotalCount(InternalItemsQuery filter, Guid ancestorId);
+
+    /// <summary>
+    /// Gets both the played count and total count of items that are linked children of the specified parent.
+    /// Uses the LinkedChildren table for BoxSets, Playlists, etc.
+    /// Applies user access filtering (library access, parental controls, tags).
+    /// </summary>
+    /// <param name="filter">The query filter containing user access settings.</param>
+    /// <param name="parentId">The parent item id (BoxSet, Playlist, etc.).</param>
+    /// <returns>A tuple containing (Played count, Total count).</returns>
+    (int Played, int Total) GetPlayedAndTotalCountFromLinkedChildren(InternalItemsQuery filter, Guid parentId);
+
+    /// <summary>
+    /// Gets the IDs of linked children for the specified parent.
+    /// </summary>
+    /// <param name="parentId">The parent item ID.</param>
+    /// <param name="childType">Optional child type filter (e.g., LocalAlternateVersion, LinkedAlternateVersion).</param>
+    /// <returns>List of child item IDs.</returns>
+    IReadOnlyList<Guid> GetLinkedChildrenIds(Guid parentId, int? childType = null);
+
+    /// <summary>
     /// Gets all artist matches from the db.
     /// </summary>
     /// <param name="artistNames">The names of the artists.</param>
     /// <returns>A map of the artist name and the potential matches.</returns>
     IReadOnlyDictionary<string, MusicArtist[]> FindArtists(IReadOnlyList<string> artistNames);
+
+    /// <summary>
+    /// Batch-fetches child counts for multiple parent folders.
+    /// Returns the count of immediate children (non-recursive) for each parent.
+    /// </summary>
+    /// <param name="parentIds">The list of parent folder IDs.</param>
+    /// <param name="userId">The user ID for access filtering.</param>
+    /// <returns>Dictionary mapping parent ID to child count.</returns>
+    Dictionary<Guid, int> GetChildCountBatch(IReadOnlyList<Guid> parentIds, Guid? userId);
 }
diff --git a/MediaBrowser.Controller/Persistence/NextUpEpisodeBatchResult.cs b/MediaBrowser.Controller/Persistence/NextUpEpisodeBatchResult.cs
new file mode 100644
index 0000000000..f5b09498b9
--- /dev/null
+++ b/MediaBrowser.Controller/Persistence/NextUpEpisodeBatchResult.cs
@@ -0,0 +1,38 @@
+using System.Collections.Generic;
+using MediaBrowser.Controller.Entities;
+
+namespace MediaBrowser.Controller.Persistence;
+
+/// <summary>
+/// Result of a batched NextUp query for a single series.
+/// </summary>
+public sealed class NextUpEpisodeBatchResult
+{
+    /// <summary>
+    /// Gets or sets the last watched episode (highest season/episode that is played).
+    /// </summary>
+    public BaseItem? LastWatched { get; set; }
+
+    /// <summary>
+    /// Gets or sets the next unwatched episode after the last watched position.
+    /// </summary>
+    public BaseItem? NextUp { get; set; }
+
+    /// <summary>
+    /// Gets or sets specials that may air between episodes.
+    /// Only populated when includeSpecials is true.
+    /// </summary>
+    public IReadOnlyList<BaseItem>? Specials { get; set; }
+
+    /// <summary>
+    /// Gets or sets the last watched episode for rewatching mode (most recently played).
+    /// Only populated when includeWatchedForRewatching is true.
+    /// </summary>
+    public BaseItem? LastWatchedForRewatching { get; set; }
+
+    /// <summary>
+    /// Gets or sets the next played episode for rewatching mode.
+    /// Only populated when includeWatchedForRewatching is true.
+    /// </summary>
+    public BaseItem? NextPlayedForRewatching { get; set; }
+}
diff --git a/MediaBrowser.LocalMetadata/Parsers/BaseItemXmlParser.cs b/MediaBrowser.LocalMetadata/Parsers/BaseItemXmlParser.cs
index 119effe791..cf1423d02d 100644
--- a/MediaBrowser.LocalMetadata/Parsers/BaseItemXmlParser.cs
+++ b/MediaBrowser.LocalMetadata/Parsers/BaseItemXmlParser.cs
@@ -780,7 +780,8 @@ namespace MediaBrowser.LocalMetadata.Parsers
         }
 
         /// <summary>
-        /// Get linked child.
+        /// Get linked child from XML. Uses deprecated Path/LibraryItemId properties for backward compatibility
+        /// with existing XML files. These will be resolved to ItemId when the linked child is accessed.
         /// </summary>
         /// <param name="reader">The xml reader.</param>
         /// <returns>The linked child.</returns>
@@ -791,6 +792,7 @@ namespace MediaBrowser.LocalMetadata.Parsers
             reader.MoveToContent();
             reader.Read();
 
+#pragma warning disable CS0618 // Type or member is obsolete - reading legacy XML format for backward compatibility
             // Loop through each element
             while (!reader.EOF && reader.ReadState == ReadState.Interactive)
             {
@@ -820,6 +822,7 @@ namespace MediaBrowser.LocalMetadata.Parsers
             {
                 return linkedItem;
             }
+#pragma warning restore CS0618
 
             return null;
         }
diff --git a/MediaBrowser.LocalMetadata/Savers/BaseXmlSaver.cs b/MediaBrowser.LocalMetadata/Savers/BaseXmlSaver.cs
index 025a815247..a065b68321 100644
--- a/MediaBrowser.LocalMetadata/Savers/BaseXmlSaver.cs
+++ b/MediaBrowser.LocalMetadata/Savers/BaseXmlSaver.cs
@@ -467,41 +467,40 @@ namespace MediaBrowser.LocalMetadata.Savers
         }
 
         /// <summary>
-        /// ADd linked children.
+        /// Add linked children.
         /// </summary>
         /// <param name="item">The item.</param>
         /// <param name="writer">The xml writer.</param>
         /// <param name="pluralNodeName">The plural node name.</param>
         /// <param name="singularNodeName">The singular node name.</param>
         /// <returns>The task object representing the asynchronous operation.</returns>
-        private static async Task AddLinkedChildren(Folder item, XmlWriter writer, string pluralNodeName, string singularNodeName)
+        private async Task AddLinkedChildren(Folder item, XmlWriter writer, string pluralNodeName, string singularNodeName)
         {
-            var items = item.LinkedChildren
+            var linkedChildren = item.LinkedChildren
                 .Where(i => i.Type == LinkedChildType.Manual)
                 .ToList();
 
-            if (items.Count == 0)
+            if (linkedChildren.Count == 0)
             {
                 return;
             }
 
             await writer.WriteStartElementAsync(null, pluralNodeName, null).ConfigureAwait(false);
 
-            foreach (var link in items)
+            foreach (var link in linkedChildren)
             {
-                if (!string.IsNullOrWhiteSpace(link.Path) || !string.IsNullOrWhiteSpace(link.LibraryItemId))
+                // Resolve ItemId to get the item's path for XML portability
+                string? path = null;
+                if (link.ItemId.HasValue && !link.ItemId.Value.Equals(Guid.Empty))
                 {
-                    await writer.WriteStartElementAsync(null, singularNodeName, null).ConfigureAwait(false);
-                    if (!string.IsNullOrWhiteSpace(link.Path))
-                    {
-                        await writer.WriteElementStringAsync(null, "Path", null, link.Path).ConfigureAwait(false);
-                    }
-
-                    if (!string.IsNullOrWhiteSpace(link.LibraryItemId))
-                    {
-                        await writer.WriteElementStringAsync(null, "ItemId", null, link.LibraryItemId).ConfigureAwait(false);
-                    }
+                    var linkedItem = LibraryManager.GetItemById(link.ItemId.Value);
+                    path = linkedItem?.Path;
+                }
 
+                if (!string.IsNullOrWhiteSpace(path))
+                {
+                    await writer.WriteStartElementAsync(null, singularNodeName, null).ConfigureAwait(false);
+                    await writer.WriteElementStringAsync(null, "Path", null, path).ConfigureAwait(false);
                     await writer.WriteEndElementAsync().ConfigureAwait(false);
                 }
             }
diff --git a/MediaBrowser.Providers/BoxSets/BoxSetMetadataService.cs b/MediaBrowser.Providers/BoxSets/BoxSetMetadataService.cs
index eccf8a606d..bdc5b5df29 100644
--- a/MediaBrowser.Providers/BoxSets/BoxSetMetadataService.cs
+++ b/MediaBrowser.Providers/BoxSets/BoxSetMetadataService.cs
@@ -70,7 +70,7 @@ public class BoxSetMetadataService : MetadataService<BoxSet, BoxSetInfo>
         if (mergeMetadataSettings)
         {
             // TODO: Change to only replace when currently empty or requested. This is currently not done because the metadata service is not handling attaching collection items based on the provider responses
-            targetItem.LinkedChildren = sourceItem.LinkedChildren.Concat(targetItem.LinkedChildren).DistinctBy(i => i.Path).ToArray();
+            targetItem.LinkedChildren = sourceItem.LinkedChildren.Concat(targetItem.LinkedChildren).DistinctBy(i => i.ItemId).ToArray();
         }
     }
 
diff --git a/MediaBrowser.Providers/Manager/ProviderManager.cs b/MediaBrowser.Providers/Manager/ProviderManager.cs
index f8e2aece1f..aad9ca2844 100644
--- a/MediaBrowser.Providers/Manager/ProviderManager.cs
+++ b/MediaBrowser.Providers/Manager/ProviderManager.cs
@@ -31,6 +31,7 @@ using MediaBrowser.Model.Extensions;
 using MediaBrowser.Model.IO;
 using MediaBrowser.Model.Net;
 using MediaBrowser.Model.Providers;
+using MediaBrowser.Model.Querying;
 using Microsoft.Extensions.Caching.Memory;
 using Microsoft.Extensions.Logging;
 using Book = MediaBrowser.Controller.Entities.Book;
@@ -69,6 +70,13 @@ namespace MediaBrowser.Providers.Manager
             o.PoolInitialFill = 1;
         });
 
+        /// <summary>
+        /// Cache for ordered metadata providers per library/item type combination.
+        /// Key: (LibraryPath, ItemTypeName, IncludeDisabled, ForceEnableInternetMetadata).
+        /// Value: Array of ordered metadata providers (before per-item filtering).
+        /// </summary>
+        private readonly ConcurrentDictionary<MetadataProviderCacheKey, IMetadataProvider[]> _metadataProviderCache = new();
+
         private IImageProvider[] _imageProviders = [];
         private IMetadataService[] _metadataServices = [];
         private IMetadataProvider[] _metadataProviders = [];
@@ -119,6 +127,8 @@ namespace MediaBrowser.Providers.Manager
             _lyricManager = lyricManager;
             _memoryCache = memoryCache;
             _mediaSegmentManager = mediaSegmentManager;
+
+            CollectionFolder.LibraryOptionsUpdated += OnLibraryOptionsUpdated;
         }
 
         /// <inheritdoc/>
@@ -427,8 +437,37 @@ namespace MediaBrowser.Providers.Manager
             where T : BaseItem
         {
             var globalMetadataOptions = GetMetadataOptions(item);
+            var libraryPath = GetLibraryPathForItem(item);
+
+            return GetMetadataProvidersInternal<T>(item, libraryOptions, globalMetadataOptions, false, false, libraryPath);
+        }
+
+        /// <summary>
+        /// Gets metadata providers for the specified item.
+        /// </summary>
+        /// <typeparam name="T">The item type.</typeparam>
+        /// <param name="item">The item.</param>
+        /// <param name="libraryOptions">The library options.</param>
+        /// <param name="includeDisabled">Whether to include disabled providers.</param>
+        /// <returns>The metadata providers.</returns>
+        public IEnumerable<IMetadataProvider<T>> GetMetadataProviders<T>(BaseItem item, LibraryOptions libraryOptions, bool includeDisabled)
+            where T : BaseItem
+        {
+            var globalMetadataOptions = GetMetadataOptions(item);
+            var libraryPath = GetLibraryPathForItem(item);
 
-            return GetMetadataProvidersInternal<T>(item, libraryOptions, globalMetadataOptions, false, false);
+            return GetMetadataProvidersInternal<T>(item, libraryOptions, globalMetadataOptions, includeDisabled, false, libraryPath);
+        }
+
+        private static string GetLibraryPathForItem(BaseItem item)
+        {
+            if (item is CollectionFolder collectionFolder)
+            {
+                return collectionFolder.Path ?? string.Empty;
+            }
+
+            var topParent = item.GetTopParent();
+            return topParent?.Path ?? string.Empty;
         }
 
         /// <inheritdoc />
@@ -437,15 +476,37 @@ namespace MediaBrowser.Providers.Manager
             return _savers.Where(i => IsSaverEnabledForItem(i, item, libraryOptions, ItemUpdateType.MetadataEdit, false));
         }
 
-        private IEnumerable<IMetadataProvider<T>> GetMetadataProvidersInternal<T>(BaseItem item, LibraryOptions libraryOptions, MetadataOptions globalMetadataOptions, bool includeDisabled, bool forceEnableInternetMetadata)
+        private IEnumerable<IMetadataProvider<T>> GetMetadataProvidersInternal<T>(BaseItem item, LibraryOptions libraryOptions, MetadataOptions globalMetadataOptions, bool includeDisabled, bool forceEnableInternetMetadata, string libraryPath)
             where T : BaseItem
         {
-            var localMetadataReaderOrder = libraryOptions.LocalMetadataReaderOrder ?? globalMetadataOptions.LocalMetadataReaderOrder;
             var typeOptions = libraryOptions.GetTypeOptions(item.GetType().Name);
+
+            var orderedProviders = GetOrCreateOrderedProviders<T>(item.GetType().Name, libraryOptions, globalMetadataOptions, includeDisabled, forceEnableInternetMetadata, libraryPath);
+
+            return orderedProviders.Where(i => CanRefreshMetadata(i, item, typeOptions, includeDisabled, forceEnableInternetMetadata));
+        }
+
+        private IMetadataProvider<T>[] GetOrCreateOrderedProviders<T>(
+            string itemTypeName,
+            LibraryOptions libraryOptions,
+            MetadataOptions globalMetadataOptions,
+            bool includeDisabled,
+            bool forceEnableInternetMetadata,
+            string libraryPath)
+            where T : BaseItem
+        {
+            var cacheKey = new MetadataProviderCacheKey(libraryPath, itemTypeName, includeDisabled, forceEnableInternetMetadata);
+            if (_metadataProviderCache.TryGetValue(cacheKey, out var cachedProviders))
+            {
+                return cachedProviders.OfType<IMetadataProvider<T>>().ToArray();
+            }
+
+            var localMetadataReaderOrder = libraryOptions.LocalMetadataReaderOrder ?? globalMetadataOptions.LocalMetadataReaderOrder;
+            var typeOptions = libraryOptions.GetTypeOptions(itemTypeName);
             var metadataFetcherOrder = typeOptions?.MetadataFetcherOrder ?? globalMetadataOptions.MetadataFetcherOrder;
 
-            return _metadataProviders.OfType<IMetadataProvider<T>>()
-                .Where(i => CanRefreshMetadata(i, item, typeOptions, includeDisabled, forceEnableInternetMetadata))
+            var orderedProviders = _metadataProviders.OfType<IMetadataProvider<T>>()
+                .Where(i => CanRefreshMetadataForCache(i, typeOptions, includeDisabled, forceEnableInternetMetadata))
                 .OrderBy(i =>
                     // local and remote providers will be interleaved in the final order
                     // only relative order within a type matters: consumers of the list filter to one or the other
@@ -456,7 +517,36 @@ namespace MediaBrowser.Providers.Manager
                         // Default to end
                         _ => int.MaxValue
                     })
-                .ThenBy(GetDefaultOrder);
+                .ThenBy(GetDefaultOrder)
+                .ToArray();
+
+            _metadataProviderCache.TryAdd(cacheKey, orderedProviders.Cast<IMetadataProvider>().ToArray());
+
+            return orderedProviders;
+        }
+
+        private static bool CanRefreshMetadataForCache(
+            IMetadataProvider provider,
+            TypeOptions? libraryTypeOptions,
+            bool includeDisabled,
+            bool forceEnableInternetMetadata)
+        {
+            if (includeDisabled)
+            {
+                return true;
+            }
+
+            if (forceEnableInternetMetadata || provider is not IRemoteMetadataProvider)
+            {
+                return true;
+            }
+
+            if (libraryTypeOptions?.MetadataFetchers is { Length: > 0 } metadataFetchers)
+            {
+                return metadataFetchers.Contains(provider.Name, StringComparer.OrdinalIgnoreCase);
+            }
+
+            return true;
         }
 
         private bool CanRefreshMetadata(
@@ -607,7 +697,8 @@ namespace MediaBrowser.Providers.Manager
         private void AddMetadataPlugins<T>(List<MetadataPlugin> list, T item, LibraryOptions libraryOptions, MetadataOptions options)
             where T : BaseItem
         {
-            var providers = GetMetadataProvidersInternal<T>(item, libraryOptions, options, true, true).ToList();
+            var libraryPath = GetLibraryPathForItem(item);
+            var providers = GetMetadataProvidersInternal<T>(item, libraryOptions, options, true, true, libraryPath).ToList();
 
             // Locals
             list.AddRange(providers.Where(i => i is ILocalMetadataProvider).Select(i => new MetadataPlugin
@@ -824,8 +915,8 @@ namespace MediaBrowser.Providers.Manager
             }
 
             var options = GetMetadataOptions(referenceItem);
-
-            var providers = GetMetadataProvidersInternal<TItemType>(referenceItem, libraryOptions, options, searchInfo.IncludeDisabledProviders, false)
+            var libraryPath = GetLibraryPathForItem(referenceItem);
+            var providers = GetMetadataProvidersInternal<TItemType>(referenceItem, libraryOptions, options, searchInfo.IncludeDisabledProviders, false, libraryPath)
                 .OfType<IRemoteSearchProvider<TLookupType>>();
 
             if (!string.IsNullOrEmpty(searchInfo.SearchProviderName))
@@ -1157,6 +1248,8 @@ namespace MediaBrowser.Providers.Manager
 
             if (disposing)
             {
+                CollectionFolder.LibraryOptionsUpdated -= OnLibraryOptionsUpdated;
+
                 if (!_disposeCancellationTokenSource.IsCancellationRequested)
                 {
                     _disposeCancellationTokenSource.Cancel();
@@ -1168,5 +1261,38 @@ namespace MediaBrowser.Providers.Manager
 
             _disposed = true;
         }
+
+        private void OnLibraryOptionsUpdated(object? sender, LibraryOptionsUpdatedEventArgs e)
+        {
+            var keysToRemove = _metadataProviderCache.Keys
+                .Where(k => string.Equals(k.LibraryPath, e.LibraryPath, StringComparison.Ordinal))
+                .ToList();
+
+            foreach (var key in keysToRemove)
+            {
+                _metadataProviderCache.TryRemove(key, out _);
+            }
+
+            _logger.LogDebug("Invalidated metadata provider cache for library: {LibraryPath}", e.LibraryPath);
+        }
+
+        internal void ClearMetadataProviderCache()
+        {
+            _metadataProviderCache.Clear();
+            _logger.LogDebug("Cleared entire metadata provider cache");
+        }
+
+        /// <summary>
+        /// Cache key for metadata provider lookups.
+        /// </summary>
+        /// <param name="LibraryPath">The library path for the collection folder.</param>
+        /// <param name="ItemTypeName">The item type name.</param>
+        /// <param name="IncludeDisabled">Whether to include disabled providers.</param>
+        /// <param name="ForceEnableInternetMetadata">Whether internet metadata is force-enabled.</param>
+        private readonly record struct MetadataProviderCacheKey(
+            string LibraryPath,
+            string ItemTypeName,
+            bool IncludeDisabled,
+            bool ForceEnableInternetMetadata);
     }
 }
diff --git a/MediaBrowser.Providers/Playlists/PlaylistItemsProvider.cs b/MediaBrowser.Providers/Playlists/PlaylistItemsProvider.cs
index 4c10fe3f1a..924fde4808 100644
--- a/MediaBrowser.Providers/Playlists/PlaylistItemsProvider.cs
+++ b/MediaBrowser.Providers/Playlists/PlaylistItemsProvider.cs
@@ -175,11 +175,11 @@ public class PlaylistItemsProvider : ILocalMetadataProvider<Playlist>,
 
     private LinkedChild GetLinkedChild(string itemPath, string playlistPath, List<string> libraryRoots)
     {
-        if (TryGetPlaylistItemPath(itemPath, playlistPath, libraryRoots, out var parsedPath))
+        if (TryResolvePlaylistItem(itemPath, playlistPath, libraryRoots, out var item))
         {
             return new LinkedChild
             {
-                Path = parsedPath,
+                ItemId = item.Id,
                 Type = LinkedChildType.Manual
             };
         }
@@ -187,9 +187,9 @@ public class PlaylistItemsProvider : ILocalMetadataProvider<Playlist>,
         return null;
     }
 
-    private bool TryGetPlaylistItemPath(string itemPath, string playlistPath, List<string> libraryPaths, out string path)
+    private bool TryResolvePlaylistItem(string itemPath, string playlistPath, List<string> libraryPaths, out BaseItem item)
     {
-        path = null;
+        item = null;
         string pathToCheck = _fileSystem.MakeAbsolutePath(Path.GetDirectoryName(playlistPath), itemPath);
         if (!File.Exists(pathToCheck))
         {
@@ -200,8 +200,8 @@ public class PlaylistItemsProvider : ILocalMetadataProvider<Playlist>,
         {
             if (pathToCheck.StartsWith(libraryPath, StringComparison.OrdinalIgnoreCase))
             {
-                path = pathToCheck;
-                return true;
+                item = _libraryManager.FindByPath(pathToCheck, null);
+                return item is not null;
             }
         }
 
diff --git a/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs b/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs
index e0a4c4f320..45b61319b7 100644
--- a/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs
+++ b/MediaBrowser.Providers/Playlists/PlaylistMetadataService.cs
@@ -72,7 +72,7 @@ public class PlaylistMetadataService : MetadataService<Playlist, ItemLookupInfo>
             }
             else
             {
-                targetItem.LinkedChildren = sourceItem.LinkedChildren.Concat(targetItem.LinkedChildren).DistinctBy(i => i.Path).ToArray();
+                targetItem.LinkedChildren = sourceItem.LinkedChildren.Concat(targetItem.LinkedChildren).DistinctBy(i => i.ItemId).ToArray();
             }
 
             if (replaceData || targetItem.Shares.Count == 0)
diff --git a/MediaBrowser.XbmcMetadata/Savers/BaseNfoSaver.cs b/MediaBrowser.XbmcMetadata/Savers/BaseNfoSaver.cs
index 0217bded13..fe596e2b75 100644
--- a/MediaBrowser.XbmcMetadata/Savers/BaseNfoSaver.cs
+++ b/MediaBrowser.XbmcMetadata/Savers/BaseNfoSaver.cs
@@ -781,26 +781,30 @@ namespace MediaBrowser.XbmcMetadata.Savers
 
         private void AddCollectionItems(Folder item, XmlWriter writer)
         {
-            var items = item.LinkedChildren
+            var linkedChildren = item.LinkedChildren
                 .Where(i => i.Type == LinkedChildType.Manual)
-                .OrderBy(i => i.Path?.Trim())
-                .ThenBy(i => i.LibraryItemId?.Trim())
                 .ToList();
 
-            foreach (var link in items)
-            {
-                writer.WriteStartElement("collectionitem");
-
-                if (!string.IsNullOrWhiteSpace(link.Path))
+            // Resolve ItemIds to paths and sort
+            var itemsWithPaths = linkedChildren
+                .Select(link =>
                 {
-                    writer.WriteElementString("path", link.Path);
-                }
+                    if (link.ItemId.HasValue && !link.ItemId.Value.Equals(Guid.Empty))
+                    {
+                        var linkedItem = LibraryManager.GetItemById(link.ItemId.Value);
+                        return linkedItem?.Path;
+                    }
 
-                if (!string.IsNullOrWhiteSpace(link.LibraryItemId))
-                {
-                    writer.WriteElementString("ItemId", link.LibraryItemId);
-                }
+                    return null;
+                })
+                .Where(path => !string.IsNullOrWhiteSpace(path))
+                .OrderBy(path => path?.Trim())
+                .ToList();
 
+            foreach (var path in itemsWithPaths)
+            {
+                writer.WriteStartElement("collectionitem");
+                writer.WriteElementString("path", path);
                 writer.WriteEndElement();
             }
         }
diff --git a/src/Jellyfin.Database/Jellyfin.Database.Implementations/IJellyfinDatabaseProvider.cs b/src/Jellyfin.Database/Jellyfin.Database.Implementations/IJellyfinDatabaseProvider.cs
index 27dbeaba6a..f52a68c684 100644
--- a/src/Jellyfin.Database/Jellyfin.Database.Implementations/IJellyfinDatabaseProvider.cs
+++ b/src/Jellyfin.Database/Jellyfin.Database.Implementations/IJellyfinDatabaseProvider.cs
@@ -18,6 +18,12 @@ public interface IJellyfinDatabaseProvider
     IDbContextFactory<JellyfinDbContext>? DbContextFactory { get; set; }
 
     /// <summary>
+    /// Gets the descendant query provider for this database type.
+    /// Used for recursive CTE queries to find all descendants of an item.
+    /// </summary>
+    IDescendantQueryProvider DescendantQueryProvider { get; }
+
+    /// <summary>
     /// Initialises jellyfins EFCore database access.
     /// </summary>
     /// <param name="options">The EFCore database options.</param>
diff --git a/src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/SqliteDatabaseProvider.cs b/src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/SqliteDatabaseProvider.cs
index da63df8e29..94c470e6cb 100644
--- a/src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/SqliteDatabaseProvider.cs
+++ b/src/Jellyfin.Database/Jellyfin.Database.Providers.Sqlite/SqliteDatabaseProvider.cs
@@ -40,6 +40,9 @@ public sealed class SqliteDatabaseProvider : IJellyfinDatabaseProvider
     public IDbContextFactory<JellyfinDbContext>? DbContextFactory { get; set; }
 
     /// <inheritdoc/>
+    public IDescendantQueryProvider DescendantQueryProvider { get; } = new SqliteDescendantQueryProvider();
+
+    /// <inheritdoc/>
     public void Initialise(DbContextOptionsBuilder options, DatabaseConfigurationOptions databaseConfiguration)
     {
         static T? GetOption<T>(ICollection<CustomDatabaseOption>? options, string key, Func<string, T> converter, Func<T>? defaultValue = null)