From bb654360bf47c0d0b586564fe746ae583a1c8bc0 Mon Sep 17 00:00:00 2001
From: Sven Geusens <sge@umbraco.dk>
Date: Wed, 31 Jul 2024 10:35:28 +0200
Subject: [PATCH] Improve migration performance (#16784)

* Improve migration performance

* Fix PR review comments

* Revert tags migration for sql lite as the optimized sql doesn't work properly and sqlLite datasets should not be large anyway
---
 .../MigrateTagsFromNVarcharToNText.cs         | 25 +++++++++++++++++++
 .../V_12_0_0/UseNvarcharInsteadOfNText.cs     | 16 ++++++++++++
 2 files changed, 41 insertions(+)

diff --git a/src/Umbraco.Infrastructure/Migrations/Upgrade/V_10_7_0/MigrateTagsFromNVarcharToNText.cs b/src/Umbraco.Infrastructure/Migrations/Upgrade/V_10_7_0/MigrateTagsFromNVarcharToNText.cs
index 9bc9856fe783..318fead2d681 100644
--- a/src/Umbraco.Infrastructure/Migrations/Upgrade/V_10_7_0/MigrateTagsFromNVarcharToNText.cs
+++ b/src/Umbraco.Infrastructure/Migrations/Upgrade/V_10_7_0/MigrateTagsFromNVarcharToNText.cs
@@ -25,6 +25,18 @@ protected override void Migrate()
         Database.Execute(updateDbTypeForTagsQuery);
 
         // Then migrate the data from "varcharValue" column to "textValue"
+        if (Database.DatabaseType == DatabaseType.SQLite)
+        {
+            MigrateSqlLiteData();
+        }
+        else
+        {
+            MigrateSqlServerData();
+        }
+    }
+
+    private void MigrateSqlLiteData()
+    {
         Sql<ISqlContext> tagsDataTypeIdQuery = Database.SqlContext.Sql()
             .Select<DataTypeDto>(dt => dt.NodeId)
             .From<DataTypeDto>()
@@ -44,4 +56,17 @@ protected override void Migrate()
 
         Database.Execute(updatePropertyDataColumnsQuery);
     }
+
+    private void MigrateSqlServerData()
+    {
+        Sql<ISqlContext> updateTagsValues = Database.SqlContext.Sql()
+            .Update<PropertyDataDto>()
+            .Append("SET textValue = COALESCE([textValue], [varCharValue]), varcharValue = null")
+            .From<DataTypeDto>()
+            .InnerJoin<PropertyTypeDto>().On<DataTypeDto, PropertyTypeDto>((dt, pt) => dt.NodeId == pt.DataTypeId)
+            .InnerJoin<PropertyDataDto>().On<PropertyTypeDto, PropertyDataDto>((pt, pd) => pt.Id == pd.PropertyTypeId)
+            .Where<DataTypeDto>(dt => dt.EditorAlias == Constants.PropertyEditors.Aliases.Tags);
+
+        Database.Execute(updateTagsValues);
+    }
 }
diff --git a/src/Umbraco.Infrastructure/Migrations/Upgrade/V_12_0_0/UseNvarcharInsteadOfNText.cs b/src/Umbraco.Infrastructure/Migrations/Upgrade/V_12_0_0/UseNvarcharInsteadOfNText.cs
index e761ccf8c489..aaa2137c61e9 100644
--- a/src/Umbraco.Infrastructure/Migrations/Upgrade/V_12_0_0/UseNvarcharInsteadOfNText.cs
+++ b/src/Umbraco.Infrastructure/Migrations/Upgrade/V_12_0_0/UseNvarcharInsteadOfNText.cs
@@ -32,6 +32,15 @@ protected override void Migrate()
         MigrateNtextColumn<PropertyDataDto>("textValue", Constants.DatabaseSchema.Tables.PropertyData, x => x.TextValue);
     }
 
+    private void RawMigrateNtextColumn(string columnName, string tableName)
+    {
+        var updateTypeSql = @$"
+ALTER TABLE {tableName}
+ALTER COLUMN {columnName} nvarchar(max)";
+        Sql<ISqlContext> copyDataQuery = Database.SqlContext.Sql(updateTypeSql);
+        Database.Execute(copyDataQuery);
+    }
+
     private void MigrateNtextColumn<TDto>(string columnName, string tableName, Expression<Func<TDto, object?>> fieldSelector, bool nullable = true)
     {
         var columnType = ColumnType(tableName, columnName);
@@ -40,6 +49,13 @@ private void MigrateNtextColumn<TDto>(string columnName, string tableName, Expre
             return;
         }
 
+        // since it's ntext to nvarchar(max) we should be able to just raw query this without having issues with fallback values on sql server
+        if (Database.DatabaseType != DatabaseType.SQLite)
+        {
+            RawMigrateNtextColumn(columnName, tableName);
+            return;
+        }
+
         var oldColumnName = $"Old{columnName}";
 
         // Rename the column so we can create the new one and copy over the data.