SelectWithUnionQuery (children 1)
 ExpressionList (children 1)
  SelectQuery (children 4)
   ExpressionList (children 1)
    Function plus (children 1)
     ExpressionList (children 2)
      Literal UInt64_1
      Identifier x
   TablesInSelectQuery (children 1)
    TablesInSelectQueryElement (children 1)
     TableExpression (children 1)
      TableIdentifier tab
   Function lessOrEquals (children 1)
    ExpressionList (children 2)
     Function plus (children 1)
      ExpressionList (children 2)
       Function CAST (children 1)
        ExpressionList (children 2)
         Literal \'1\'
         Literal \'LowCardinality(Nullable(UInt8))\'
       Identifier x
     Literal UInt64_2
   ExpressionList (children 1)
    OrderByElement (children 1)
     Identifier x
