docs: protected int getMaxIndexKeys() throws SQLException {
      if (indexMaxKeys == 0) {
        String sql;
        sql = "SELECT setting FROM pg_catalog.pg_settings WHERE name='max_index_keys'";
  
        Statement stmt = connection.createStatement();
        ResultSet rs = null;
        try {
          rs = stmt.executeQuery(sql);
          if (!rs.next()) {
            stmt.close();
            throw new PSQLException(
                GT.tr(
                    "Unable to determine a value for MaxIndexKeys due to missing system catalog data."),
                PSQLState.UNEXPECTED_ERROR);
          }
          indexMaxKeys = rs.getInt(1);
        } finally {
          JdbcBlackHole.close(rs);
          JdbcBlackHole.close(stmt);
        }
      }
      return indexMaxKeys;
    }