Re: select count(*) from pg_stat_activity in V8.0.0

Поиск
Список
Период
Сортировка
От Richard Huxton
Тема Re: select count(*) from pg_stat_activity in V8.0.0
Дата
Msg-id 4124EC03.2090106@archonet.com
обсуждение исходный текст
Ответ на Re: select count(*) from pg_stat_activity in V8.0.0  ("Anony Mous" <A.Mous@shaw.ca>)
Список pgsql-general
Anony Mous wrote:
> Thanks, Richard.
>
> I've never seen this behaviour before in 7.4.3 and indeed it is the only
> connection to the back end at the time when the count is occurring. However,
> it would have had the connection for at least 30 seconds before requesting a
> count.
>
> Is there a better method of obtaining the number of connections to the
> backend?

Other than "ps" - no I don't think so. The 30 seconds doesn't sound
right, Tom reckoned 0.5sec which sounds plausible. Might this be the
first query you've sent on this connection?

I'm wondering if the ODBC connection isn't actually established until
you run the first query? It doesn't sound right to me, but I don't have
any of my ODBC apps to hand at the moment to check.

Could you:
1. Connect
2. SELECT 1; (or similar)
3. Sleep from 10msec => 1sec
4. SELECT * FROM pg_stat_activity;

That way we could disable step 2 and tinker with the delay in step 3 to
see what happens.

--
   Richard Huxton
   Archonet Ltd

В списке pgsql-general по дате отправления:

Предыдущее
От: Gaetano Mendola
Дата:
Сообщение: Re: Finally tsearch works ... somehow... remain a few
Следующее
От: Shelby Cain
Дата:
Сообщение: Re: Postgresql 8.0 beta 1 - strange cpu usage statistics and slow vacuuming