Explain EXPLAIN SYNTAX (children 1)
 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 1)
           ExpressionList (children 2)
            Literal UInt64_1 (alias id)
            Subquery (alias subquery) (children 1)
             SelectWithUnionQuery (children 1)
              ExpressionList (children 1)
               SelectQuery (children 1)
                ExpressionList (children 1)
                 Literal UInt64_1
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier subquery
      Literal UInt64_1
