docs: @Override
      public ResultSet getImportedKeys(String catalog, String schema, String table) throws SQLException
      {
          checkClosed();
          VoltTable vtable = new VoltTable(
                  new ColumnInfo("PKTABLE_CAT", VoltType.STRING),
                  new ColumnInfo("PKTABLE_SCHEM", VoltType.STRING),
                  new ColumnInfo("PKTABLE_NAME", VoltType.STRING),
                  new ColumnInfo("PKCOLUMN_NAME", VoltType.STRING),
                  new ColumnInfo("FKTABLE_CAT", VoltType.STRING),
                  new ColumnInfo("FKTABLE_SCHEM", VoltType.STRING),
                  new ColumnInfo("FKTABLE_NAME", VoltType.STRING),
                  new ColumnInfo("FKCOLUMN_NAME", VoltType.STRING),
                  new ColumnInfo("KEY_SEQ", VoltType.SMALLINT),
                  new ColumnInfo("UPDATE_RULE", VoltType.SMALLINT),
                  new ColumnInfo("DELETE_RULE", VoltType.SMALLINT),
                  new ColumnInfo("FK_NAME", VoltType.STRING),
                  new ColumnInfo("PK_NAME", VoltType.STRING),
                  new ColumnInfo("DEFERRABILITY", VoltType.SMALLINT)
          );
          //NB: @SystemCatalog(?) will need additional support if we want to
          // populate the table.
          JDBC4ResultSet res = new JDBC4ResultSet(this.sysCatalog, vtable);
          return res;
      }