@Override
  protected Boolean visitLogicalExpression(final LogicalExpression node, final Void context) {
    final List<Expression> children = node.getTerms();
    for (final Expression child : children) {
      final Boolean result = process(child, context);
      if (result == null) {
        throw new IllegalStateException("Should never return null.");
      }
      if (!result) {
        return Boolean.FALSE;
      }
    }
    return Boolean.TRUE;
  }
only the following predicate will return true: 1. tagColumn = 'XXX' 2. 'XXX' = tagColumn 3.
attributeColumn = 'XXX' 4. 'XXX' = attributeColumn 5. tagColumn/attributeColumn IS NULL 6. using
or to combine the above expression
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/queryengine/plan/relational/analyzer/predicate/PredicatePushIntoMetadataChecker.java