Re: Slow update with simple query

Поиск
Список
Период
Сортировка
От Tom Lane
Тема Re: Slow update with simple query
Дата
Msg-id 21233.1166113140@sss.pgh.pa.us
обсуждение исходный текст
Ответ на Re: Slow update with simple query  (Arnaud Lesauvage <thewild@freesurf.fr>)
Ответы Re: Slow update with simple query  (Arnaud Lesauvage <thewild@freesurf.fr>)
Re: Slow update with simple query  (Mark Lewis <mark.lewis@mir3.com>)
Список pgsql-performance
Arnaud Lesauvage <thewild@freesurf.fr> writes:
> Tom Lane a �crit :
>> It seems the time must be going into this trigger function.  What
>> does it do?

> A lot of things ! Indeed, if it runs it will very badly hurt performances (table
> lookups, string manipulation, etc...) !
> But it should only be tringered on INSERTs, and I am doing an UPDATE !

Doh, right, I obviously still need to ingest more caffeine this morning.

I think the conclusion must be that there was just too much I/O to be
done to update all the rows.  Have you done any tuning of shared_buffers
and so forth?  I recall having seen cases where update performance went
bad as soon as the upper levels of a large index no longer fit into
shared_buffers ...

            regards, tom lane

В списке pgsql-performance по дате отправления:

Предыдущее
От: Matthew O'Connor
Дата:
Сообщение: Re: New to PostgreSQL, performance considerations
Следующее
От: Arnaud Lesauvage
Дата:
Сообщение: Re: Slow update with simple query