code: @Override
      public boolean isConnected(final Connection _connection)
          throws SQLException
      {
          boolean ret = false;
          final StringBuilder cmd = new StringBuilder();
          cmd.append(" SELECT version();");
          PreparedStatement stmt = null;
          stmt = _connection.prepareStatement(cmd.toString());
          try {
              final ResultSet resultset = stmt.executeQuery();
              if (resultset.next()) {
                  final String str = resultset.getString(1);
                  ret = str.toUpperCase().contains("POSTGRESQL");
              }
              resultset.close();
          } finally {
              stmt.close();
          }
          return ret;
      }
docs: {@inheritDoc}