1 files changed, 50 insertions, 0 deletions
diff --git a/lib/gitlab/database/migration_helpers/swapping.rb b/lib/gitlab/database/migration_helpers/swapping.rb
new file mode 100644
index 00000000000..6d19f8002d8
--- /dev/null
+++ b/lib/gitlab/database/migration_helpers/swapping.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Database
+    module MigrationHelpers
+      module Swapping
+        def reset_trigger_function(function_name)
+          execute("ALTER FUNCTION #{quote_table_name(function_name)} RESET ALL")
+        end
+
+        def swap_columns(table, column1, column2)
+          ::Gitlab::Database::Migrations::SwapColumns.new(
+            migration_context: self,
+            table: table,
+            column1: column1,
+            column2: column2
+          ).execute
+        end
+
+        def swap_columns_default(table, column1, column2)
+          ::Gitlab::Database::Migrations::SwapColumnsDefault.new(
+            migration_context: self,
+            table: table,
+            column1: column1,
+            column2: column2
+          ).execute
+        end
+
+        def swap_foreign_keys(table, foreign_key1, foreign_key2)
+          rename_constraint(table, foreign_key1, :temp_name_for_renaming)
+          rename_constraint(table, foreign_key2, foreign_key1)
+          rename_constraint(table, :temp_name_for_renaming, foreign_key2)
+        end
+
+        def swap_indexes(table, index1, index2)
+          identifier = "index_#{index1}_on_#{table}"
+          # Check Gitlab::Database::MigrationHelpers#concurrent_foreign_key_name()
+          # for info on why we use a hash
+          hashed_identifier = Digest::SHA256.hexdigest(identifier).first(10)
+
+          temp_index = "temp_#{hashed_identifier}"
+
+          rename_index(table, index1, temp_index)
+          rename_index(table, index2, index1)
+          rename_index(table, temp_index, index2)
+        end
+      end
+    end
+  end
+end