PostgreSQL Bugs List wrote:
> Hello All,
> We are using PostgreSQL 7.4.2 for our website that handles over 200,000
> transactions a day.
> About a month ago, the responses from the SELECT queries on the database
> became terribly slow.
> We tried to anaylze the cause of the problem, searching throught the system
> logs and all, but nothing appeared to be out of the ordinary.
>
> What we did to resolve this was to dump the database, delete the database,
> recreate the database, and finally restore it. After that, things were back
> to normal.
>
> From the above experience, we were able to hypothesize that the fault of the
> slow responses was not from a broken data or hardware failures, but from a
> broken index, since we were able to recover 100% of the data on the same
> machine.
>
> Today, the same problem occured, and the same actions are going to be taken
> to temporary resolve it.
>
> Final note: we will also experiment with the 'vacuum full' command to see
> if it counters this problem.
This is not for sure a bug, but a known behaviour if you don't vacuum at all
your db. I bet you don't use the vacuum daemon; use it or schedule a simple
vacuum on the eavily updated table each 10 minutes. I strongly suggest you to use
the autovacuum daemon.
Do not esitate to ask how use it.
Regards
Gaetano Mendola