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 2)
           ExpressionList (children 1)
            Asterisk
           TablesInSelectQuery (children 2)
            TablesInSelectQueryElement (children 1)
             TableExpression (children 1)
              Subquery (alias a) (children 1)
               SelectWithUnionQuery (children 1)
                ExpressionList (children 1)
                 SelectQuery (children 2)
                  ExpressionList (children 1)
                   Asterisk
                  TablesInSelectQuery (children 1)
                   TablesInSelectQueryElement (children 1)
                    TableExpression (children 1)
                     TableIdentifier test_00597
            TablesInSelectQueryElement (children 2)
             TableExpression (children 1)
              Subquery (alias b) (children 1)
               SelectWithUnionQuery (children 1)
                ExpressionList (children 1)
                 SelectQuery (children 2)
                  ExpressionList (children 1)
                   Asterisk
                  TablesInSelectQuery (children 1)
                   TablesInSelectQueryElement (children 1)
                    TableExpression (children 1)
                     TableIdentifier test_00597
             TableJoin (children 1)
              Function equals (children 1)
               ExpressionList (children 2)
                Identifier a.id
                Identifier b.id
    Function equals (children 1)
     ExpressionList (children 2)
      Identifier id
      Literal UInt64_1
