@Override
    public boolean apply(SamzaSqlInputMessage samzaSqlInputMessage) {
      return !samzaSqlInputMessage.getMetadata().isSystemMessage();
    }
Translator to translate the TableScans in relational graph to the corresponding input streams in the StreamGraph
implementation
samza-sql/src/main/java/org/apache/samza/sql/translator/ScanTranslator.java