SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Function arraySort (children 1) ExpressionList (children 1) Function arraySymmetricDifference (children 1) ExpressionList (children 2) Literal Array_[UInt64_1, NULL] Literal Array_[NULL, UInt64_3]