Explain EXPLAIN (children 2)
 Set
 SelectWithUnionQuery (children 1)
  ExpressionList (children 1)
   SelectQuery (children 3)
    ExpressionList (children 1)
     Identifier number
    TablesInSelectQuery (children 1)
     TablesInSelectQueryElement (children 1)
      TableExpression (children 1)
       Subquery (children 1)
        SelectWithUnionQuery (children 1)
         ExpressionList (children 1)
          SelectQuery (children 3)
           ExpressionList (children 1)
            Identifier number
           TablesInSelectQuery (children 1)
            TablesInSelectQueryElement (children 1)
             TableExpression (children 1)
              Function numbers (children 1)
               ExpressionList (children 1)
                Literal UInt64_2
           ExpressionList (children 1)
            OrderByElement (children 1)
             Function ignore (children 1)
              ExpressionList (children 1)
               Literal UInt64_2
    Function ignore (children 1)
     ExpressionList (children 1)
      Literal UInt64_2
