public static boolean isConstantStruct(ExprNodeDesc valueDesc) {
    return valueDesc instanceof ExprNodeConstantDesc && valueDesc.getTypeInfo() instanceof StructTypeInfo;
  }
Checks whether the keys of a child operator are a prefix of the keys of a
parent operator.
@param childKeys keys of the child operator
@param parentKeys keys of the parent operator
@param childOp child operator
@param parentOp parent operator
@return true if the keys are a prefix, false otherwise
@throws SemanticException
ql/src/java/org/apache/hadoop/hive/ql/plan/ExprNodeDescUtils.java