Re: count(*) performance improvement ideas

Поиск
Список
Период
Сортировка
От Stephen Denne
Тема Re: count(*) performance improvement ideas
Дата
Msg-id F0238EBA67824444BC1CB4700960CB48051D6243@dmpeints002.isotach.com
обсуждение исходный текст
Ответ на Re: count(*) performance improvement ideas  (PFC <lists@peufeu.com>)
Ответы Re: count(*) performance improvement ideas  ("Stephen Denne" <Stephen.Denne@datamail.co.nz>)
Список pgsql-hackers
PFC wrote
> <Stephen.Denne@datamail.co.nz> wrote:
> > I don't know plpythonu (nor python), just read a few docs now:
> 
>     Learn Python, it is a really useful language ;)

My wife has a snake phobia, besides, I've just started learning Scala.


>     There is no sharing between processes, so
>     - both SD and GD are limited to the current session 
> (connection, postgres  
> process), no shared memory is involved
>     - GD is global between all python functions (global)
>     - SD is specific to each python function (static)

Thanks.

>     The big gotcha is that these are all non-transactional 
> : if you rollback,  
> GD and SD stay the same, and when you issue a query, you can 
> assume the  
> state of SD and GD is random (due to previous queries) unless you  
> initialize them to a known value.

Using txid_current() as a key should alleviate that.

Regards,
Stephen Denne.

Disclaimer:
At the Datamail Group we value team commitment, respect, achievement, customer focus, and courage. This email with any
attachmentsis confidential and may be subject to legal privilege.  If it is not intended for you please advise by reply
immediately,destroy it and do not copy, disclose or use it in any way. 
__________________________________________________________________ This email has been scanned by the DMZGlobal
BusinessQuality             Electronic Messaging Suite. 
Please see http://www.dmzglobal.com/dmzmessaging.htm for details.
__________________________________________________________________


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Heikki Linnakangas
Дата:
Сообщение: Re: Patch for Prevent pg_dump/pg_restore from being affected by statement_timeout
Следующее
От: Andreas 'ads' Scherbaum
Дата:
Сообщение: Re: get rid of psql welcome message