classAddUsersLowerUsernameEmailIndexes<ActiveRecord::Migrationdisable_ddl_transaction!defupreturnunlessGitlab::Database.postgresql?execute'CREATE INDEX CONCURRENTLY index_on_users_lower_username ON users (LOWER(username));'execute'CREATE INDEX CONCURRENTLY index_on_users_lower_email ON users (LOWER(email));'enddefdownreturnunlessGitlab::Database.postgresql?remove_index:users,:index_on_users_lower_usernameremove_index:users,:index_on_users_lower_emailendend