@Override
    public boolean supportsTransactionIsolationLevel(int level) throws SQLException {
        try {
            return level == connection.getTransactionIsolation();
        } catch (Exception e) {
            throw ExceptionUtils.toSqlState(e);
        }
    }
Catalog term relates to the top level scale like clusters, something that joins multiple databases
Returns most close term to catalog in ClickHouse which is "cluster".
@return - string "cluster"
jdbc-v2/src/main/java/com/clickhouse/jdbc/metadata/DatabaseMetaDataImpl.java