isMariaDb() && version_compare($connection->version(), '8.0.0-AnyName', '>')) { $query = 'SELECT @@SESSION.transaction_isolation'; } $isolation_level = $connection->query($query)->fetchField(); if ($isolation_level !== 'READ-COMMITTED') { $requirements['mysql_transaction_level'] = [ 'title' => t('Database Isolation Level'), 'severity' => REQUIREMENT_WARNING, 'value' => t('Transaction Isolation Level: @value', ['@value' => $isolation_level]), 'description' => t('For the best performance and to minimize locking issues, the READ-COMMITTED transaction isolation level is recommended.', [ ':performance_doc' => 'https://www.drupal.org/docs/system-requirements/setting-the-mysql-transaction-isolation-level', ]), ]; } } } return $requirements; }