docs: @Override
      public ResultSet getSchemas() throws SQLException
      {
          checkClosed();
          VoltTable vtable = new VoltTable(
                  new ColumnInfo("TABLE_SCHEM", VoltType.STRING),
                  new ColumnInfo("TABLE_CATALOG", VoltType.STRING));
          JDBC4ResultSet res = new JDBC4ResultSet(this.sysCatalog, vtable);
          return res;
      }