docs: @Override
      public ResultSet getPrimaryKeys(String catalog, String schema, String table) throws SQLException
      {
          assert(table != null && !table.isEmpty());
          checkClosed();
          this.sysCatalog.setString(1, "PRIMARYKEYS");
          JDBC4ResultSet res = (JDBC4ResultSet) this.sysCatalog.executeQuery();
          VoltTable vtable = res.getVoltTable().clone(0);
  
          // Filter the primary keys based on table name
          while (res.next()) {
              if (res.getString("TABLE_NAME").equals(table)) {
                  vtable.addRow(res.getRowData());
              }
          }
          return new JDBC4ResultSet(sysCatalog, vtable);
      }