Fixed: Slow db migration when upgrading from v2 to v3 with a large collection

src/NzbDrone.Core/Datastore/Migration/102_add_language_to_episodeFiles_history_and_blacklist.cs

@@ -1,9 +1,12 @@
-using System.Data;
+using System;
+using System.Collections.Generic;
+using System.Data;
+using System.Linq;
 using FluentMigrator;
+using NzbDrone.Common.Extensions;
 using NzbDrone.Core.Datastore.Migration.Framework;
 using NzbDrone.Core.Datastore.Converters;
 using NzbDrone.Core.Languages;
-using System;
 
 namespace NzbDrone.Core.Datastore.Migration
 {
@@ -28,42 +31,58 @@ namespace NzbDrone.Core.Datastore.Migration
         {
             var LanguageConverter = new EmbeddedDocumentConverter(new LanguageIntConverter());
 
-            using (IDbCommand getSeriesCmd = conn.CreateCommand())
-            {
-                getSeriesCmd.Transaction = tran;
-                getSeriesCmd.CommandText = @"SELECT Id, ProfileId FROM Series";
-                using (IDataReader seriesReader = getSeriesCmd.ExecuteReader())
-                {
-                    while (seriesReader.Read())
-                    {
-                        var seriesId = seriesReader.GetInt32(0);
-                        var seriesProfileId = seriesReader.GetInt32(1);
-
+            var profileLanguages = new Dictionary<int, int>();
             using (IDbCommand getProfileCmd = conn.CreateCommand())
             {
                 getProfileCmd.Transaction = tran;
-                            getProfileCmd.CommandText = "SELECT Language FROM Profiles WHERE Id = ?";
-                            getProfileCmd.AddParameter(seriesProfileId);
+                getProfileCmd.CommandText = "SELECT Id, Language FROM Profiles";
+
                 IDataReader profilesReader = getProfileCmd.ExecuteReader();
                 while (profilesReader.Read())
                 {
+                    var profileId = profilesReader.GetInt32(0);
                     var episodeLanguage = Language.English.Id;
                     try
                     {
-                                    episodeLanguage = profilesReader.GetInt32(0);
-                                } catch (InvalidCastException e)
+                        episodeLanguage = profilesReader.GetInt32(1);
+                    }
+                    catch (InvalidCastException e)
                     {
                         _logger.Debug("Language field not found in Profiles, using English as default." + e.Message);
                     }
 
-                                var validJson = LanguageConverter.ToDB(Language.FindById(episodeLanguage));
+                    profileLanguages[profileId] = episodeLanguage;
+                }
+            }
+
+            var seriesLanguages = new Dictionary<int, int>();
+            using (IDbCommand getSeriesCmd = conn.CreateCommand())
+            {
+                getSeriesCmd.Transaction = tran;
+                getSeriesCmd.CommandText = @"SELECT Id, ProfileId FROM Series";
+                using (IDataReader seriesReader = getSeriesCmd.ExecuteReader())
+                {
+                    while (seriesReader.Read())
+                    {
+                        var seriesId = seriesReader.GetInt32(0);
+                        var seriesProfileId = seriesReader.GetInt32(1);
+
+                        seriesLanguages[seriesId] = profileLanguages.GetValueOrDefault(seriesProfileId, Language.English.Id);
+                    }
+                }
+            }
+
+            foreach (var group in seriesLanguages.GroupBy(v => v.Value, v => v.Key))
+            {
+                var languageJson = LanguageConverter.ToDB(Language.FindById(group.Key));
+
+                var seriesIds = group.Select(v => v.ToString()).Join(",");
 
                 using (IDbCommand updateEpisodeFilesCmd = conn.CreateCommand())
                 {
                     updateEpisodeFilesCmd.Transaction = tran;
-                                    updateEpisodeFilesCmd.CommandText = "UPDATE EpisodeFiles SET Language = ? WHERE SeriesId = ?";
-                                    updateEpisodeFilesCmd.AddParameter(validJson);
-                                    updateEpisodeFilesCmd.AddParameter(seriesId);
+                    updateEpisodeFilesCmd.CommandText = $"UPDATE EpisodeFiles SET Language = ? WHERE SeriesId IN ({seriesIds})";
+                    updateEpisodeFilesCmd.AddParameter(languageJson);
 
                     updateEpisodeFilesCmd.ExecuteNonQuery();
                 }
@@ -71,9 +90,8 @@ namespace NzbDrone.Core.Datastore.Migration
                 using (IDbCommand updateHistoryCmd = conn.CreateCommand())
                 {
                     updateHistoryCmd.Transaction = tran;
-                                    updateHistoryCmd.CommandText = "UPDATE History SET Language = ? WHERE SeriesId = ?";
-                                    updateHistoryCmd.AddParameter(validJson);
-                                    updateHistoryCmd.AddParameter(seriesId);
+                    updateHistoryCmd.CommandText = $"UPDATE History SET Language = ? WHERE SeriesId IN ({seriesIds})";
+                    updateHistoryCmd.AddParameter(languageJson);
 
                     updateHistoryCmd.ExecuteNonQuery();
                 }
@@ -81,9 +99,8 @@ namespace NzbDrone.Core.Datastore.Migration
                 using (IDbCommand updateBlacklistCmd = conn.CreateCommand())
                 {
                     updateBlacklistCmd.Transaction = tran;
-                                    updateBlacklistCmd.CommandText = "UPDATE Blacklist SET Language = ? WHERE SeriesId = ?";
-                                    updateBlacklistCmd.AddParameter(validJson);
-                                    updateBlacklistCmd.AddParameter(seriesId);
+                    updateBlacklistCmd.CommandText = $"UPDATE Blacklist SET Language = ? WHERE SeriesId IN ({seriesIds})";
+                    updateBlacklistCmd.AddParameter(languageJson);
 
                     updateBlacklistCmd.ExecuteNonQuery();
                 }
@@ -91,7 +108,3 @@ namespace NzbDrone.Core.Datastore.Migration
         }
     }
 }
-            }
-        }
-    }
-}