update query taking too long

Поиск
Список
Период
Сортировка
Hi all,

I'm trying to do an update of a reasonably large table and it's taking
way too long so I'm trying to work out why and if I need to tweak any
settings to speed it up.

The table is around 3.5 million records.

The query is

update table set domainname=substring(emailaddress from position('@' in
emailaddress));

I've left it running for over 20 minutes and it hasn't finished so I'm
doing something terribly bad but I have no idea what ;)

Maybe there's another way to write the query but I'm not sure how to
make it better.

Most settings are default, I have bumped up shared_buffers a bit to
65536 - I think that works out to 512Meg ? The machine has 2G ram.

Running version 8.1.9.

Any pointers about settings etc are most welcome.

--
Postgresql & php tutorials
http://www.designmagick.com/

В списке pgsql-performance по дате отправления:

Предыдущее
От: "Evan Reiser"
Дата:
Сообщение: High IOWAIT times, low iops? Need Help with configuration
Следующее
От: "A. Kretschmer"
Дата:
Сообщение: Re: update query taking too long