SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Function arraySort (children 1) ExpressionList (children 1) Function arrayUnion (children 1) ExpressionList (children 3) Literal Array_[UInt64_1, UInt64_2, NULL] Literal Array_[UInt64_1, UInt64_3, NULL] Literal Array_[UInt64_2, UInt64_3, NULL]