SelectWithUnionQuery (children 1) ExpressionList (children 1) SelectQuery (children 1) ExpressionList (children 1) Function toTypeName (children 1) ExpressionList (children 1) Function array (children 1) ExpressionList (children 2) Function materialize (children 1) ExpressionList (children 1) Function toLowCardinality (children 1) ExpressionList (children 1) Literal \'1\' Literal \'2\'