Re: [HACKERS] Phantom row from aggregate in self-join in 6.5

Поиск
Список
Период
Сортировка
От Philip Warner
Тема Re: [HACKERS] Phantom row from aggregate in self-join in 6.5
Дата
Msg-id 3.0.5.32.19990723113942.00b1b100@mail.rhyme.com.au
обсуждение исходный текст
Ответ на Re: [HACKERS] Phantom row from aggregate in self-join in 6.5  (Tom Lane <tgl@sss.pgh.pa.us>)
Ответы Re: [HACKERS] Phantom row from aggregate in self-join in 6.5  (Don Baccus <dhogaza@pacifier.com>)
Список pgsql-hackers
At 20:52 22/07/99 -0400, you wrote:
>Malcolm Beattie <mbeattie@sable.ox.ac.uk> writes:
>> Using 6.5 (via Thomas Lockhart's Linux RPM build of Jul 2), I get a
>> phantom row when doing the following:
>>     create table foo (a int);
>>     select t1.a, count(*) from foo t1, foo t2 group by t1.a;
>> I get
>>     a|count
>>     -+-----
>>      |    0
>>     (1 row)
>> instead of zero rows.
>
>It's not a bug, it's a feature ... or at least there are some around
>here who claim that the behavior is OK.  I think they're wrong, but
>if you want it changed you'll need to cite chapter and verse from the
>SQL92 standard, not just assert that Informix does it differently.

I've now checked Dec Rdb, SQL/Server, and MS-Access - and they return 0 rows. Add this to Informix, and one begins to
wonderif there are any that match the Postgres behaviour?
 

Any idea where I can find a copy of the SQL92 standard on the net?


>You'll find several past discussions of this point in the pgsql-hackers
>archives, and they all seem to have ended inconclusively.

I had a quick look at discussions involving informix, but could not find anything. Can you give a little more
informationabout the past discussions, and specifically, what the reasons for preserving this behaviour were?
 


>> is it just a buglet that can be fixed fairly easily?
>
>I think it would not be hard to fix, if we have a consensus that the
>behavior should change.
>

----------------------------------------------------------------
Philip Warner                    |     __---_____
Albatross Consulting Pty. Ltd.   |----/       -  \
(A.C.N. 008 659 498)             |          /(@)   ______---_
Tel: +61-03-5367 7422            |                 _________  \
Fax: +61-03-5367 7430            |                 ___________ |
Http://www.rhyme.com.au          |                /           \|                                |    --________--
PGP key available upon request,  |  /
and from pgp5.ai.mit.edu:11371   |/


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: [HACKERS] Phantom row from aggregate in self-join in 6.5
Следующее
От: Mark Hollomon
Дата:
Сообщение: oopsy in dynloader.c