Re: WITH RECURSIVE patch V0.1

Yoshiyuki Asaba írta:
> Hi,
>
> From: Zoltan Boszormenyi <zb@cybertec.at>
> Subject: Re: [PATCHES] WITH RECURSIVE patch V0.1
> Date: Mon, 19 May 2008 08:19:17 +0200
>
>
>>>> Also, it seems there are no infinite recursion detection:
>>>>
>>>> # with recursive x(level, parent, child) as (
>>>>    select 1::integer, * from test_connect_by where parent is null
>>>>    union all
>>>>    select x.level + 1, base.* from test_connect_by as base, x where base.child
>>>> = x.child
>>>> ) select * from x;
>>>> ... it waits and waits and waits ...
>>>>
>>>>
>>> Well, psql might wait and wait but it's actually receiving rows. A cleverer
>>> client should be able to deal with infinite streams of records.
>>>
>>>
>> I think it's the other way around. The server should not emit infinite
>> number of records.
>>
>
> How about adding new GUC parameter "max_recursive_call"?
>

Yes, why not?
MSSQL has a similar MAXRECURSION hint for WITH RECURSIVE queries
according to their docs.
http://msdn.microsoft.com/en-us/library/ms186243.aspx

> Regards,
> --
> Yoshiyuki Asaba
> y-asaba@sraoss.co.jp
>
>


--
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Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
http://www.postgresql.at/