SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 2)
   ExpressionList (children 1)
    Function count (children 1)
     ExpressionList
   TablesInSelectQuery (children 2)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier big_array
    TablesInSelectQueryElement (children 1)
     ArrayJoin (children 1)
      ExpressionList (children 1)
       Identifier x