1 files changed, 21 insertions, 0 deletions
diff --git a/db/post_migrate/20201002175953_add_index_for_merged_merge_requests.rb b/db/post_migrate/20201002175953_add_index_for_merged_merge_requests.rb
new file mode 100644
index 00000000000..cd663f3da89
--- /dev/null
+++ b/db/post_migrate/20201002175953_add_index_for_merged_merge_requests.rb
@@ -0,0 +1,21 @@
+# frozen_string_literal: true
+
+class AddIndexForMergedMergeRequests < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+  INDEX_NAME = 'idx_merge_requests_on_merged_state'
+
+  disable_ddl_transaction!
+
+  def up
+    add_concurrent_index :merge_requests,
+                         :id,
+                         where: 'state_id = 3',
+                         name: INDEX_NAME
+  end
+
+  def down
+    remove_concurrent_index_by_name :merge_requests, INDEX_NAME
+  end
+end