1 files changed, 24 insertions, 0 deletions
diff --git a/db/post_migrate/20210402005225_add_source_and_level_index_on_notification_settings.rb b/db/post_migrate/20210402005225_add_source_and_level_index_on_notification_settings.rb
new file mode 100644
index 00000000000..a29babca93e
--- /dev/null
+++ b/db/post_migrate/20210402005225_add_source_and_level_index_on_notification_settings.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+class AddSourceAndLevelIndexOnNotificationSettings < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  INDEX_WITH_SOURCE_LEVEL_USER_NAME = 'index_notification_settings_on_source_and_level_and_user'
+  INDEX_WITH_SOURCE_NAME = 'index_notification_settings_on_source_id_and_source_type'
+  INDEX_WITH_USER_NAME = 'index_notification_settings_on_user_id'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :notification_settings, [:source_id, :source_type, :level, :user_id], name: INDEX_WITH_SOURCE_LEVEL_USER_NAME
+    remove_concurrent_index_by_name :notification_settings, INDEX_WITH_SOURCE_NAME # Above index expands this index
+    remove_concurrent_index_by_name :notification_settings, INDEX_WITH_USER_NAME # It is redundant as we already have unique index on (user_id, source_id, source_type)
+  end
+
+  def down
+    add_concurrent_index :notification_settings, [:source_id, :source_type], name: INDEX_WITH_SOURCE_NAME
+    add_concurrent_index :notification_settings, [:user_id], name: INDEX_WITH_USER_NAME
+    remove_concurrent_index_by_name :notification_settings, INDEX_WITH_SOURCE_LEVEL_USER_NAME
+  end
+end