SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function dictGetKeys (children 1)
     ExpressionList (children 3)
      Literal \'dict_valexpr\'
      Literal \'s\'
      Function CAST (children 1)
       ExpressionList (children 2)
        Identifier v
        Literal \'LowCardinality(String)\'
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      Subquery (children 1)
       SelectWithUnionQuery (children 1)
        ExpressionList (children 1)
         SelectQuery (children 1)
          ExpressionList (children 1)
           Function arrayJoin (alias v) (children 1)
            ExpressionList (children 1)
             Literal Array_[\'alpha\', \'beta\', \'zzz\']
