code: protected InputStream getBinaryStreamImpl() throws SQLException {
  
          try {
              return new GZIPInputStream(
                  new ByteArrayInputStream(getGZipData()));
          } catch (IOException ex) {
              throw Exceptions.transformFailed(ex);
          }
      }
docs: Retrieves a stream representing the XML value designated by this
  SQLXML instance. <p>
  
  @return a stream containing the XML data.
  @throws SQLException if there is an error processing the XML value.