Explain EXPLAIN (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Asterisk
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Subquery (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 3)
           ExpressionList (children 2)
            Identifier x
            Function sum (children 1)
             ExpressionList (children 1)
              Identifier y
           TablesInSelectQuery (children 1)
            TablesInSelectQueryElement (children 1)
             TableExpression (children 1)
              Function remote (children 1)
               ExpressionList (children 3)
                Literal \'127.0.0.{1,2}\'
                Function currentDatabase (children 1)
                 ExpressionList
                Identifier tab
           ExpressionList (children 2)
            ExpressionList (children 2)
             Identifier x
             Function plus (children 1)
              ExpressionList (children 2)
               Identifier z
               Literal UInt64_1
            ExpressionList (children 2)
             Identifier x
             Function plus (children 1)
              ExpressionList (children 2)
               Identifier z
               Literal UInt64_2
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier x
      Literal UInt64_42
