RE: Lack of Performance - Mailing list pgsql-admin

From Andrew Snow
Subject RE: Lack of Performance
Date
Msg-id JEEGIJPOJIGGIIHGKOKOCEEKCFAA.andrew@modulus.org
Whole thread Raw
In response to RE: Lack of Performance  ("Toma Vailikit" <toma@nutz.org>)
List pgsql-admin
> What I dont understand about it, is that the DB is not THAT big.
> The tables
> are arround 10.000-30.000 rows and there are only about 6 tables. They all
> use indexes where needed and everything is vacuumed up to 8 times
> a day. But
> the load is not affected by it. I can't seem to find "what" is
> pressing the
> db.

> Does query optimization help a lot or does it only affect the
> performance in a little manner?

I think you need to be looking at your queries to see if one or more of them
is causing the performance problem.  Look at all the EXPLAIN output for each
query, and also be aware that certain operations are always going to be
slow, eg. a function call for every row of a large table, or using the
builtin regular expression operators I found to be VERY slow.

Perhaps post more details here to the list in case anyone can spot anything.
Do some tests and find which query takes the longest.  Find out if it is
actually postgresql that is using all the CPU time. Include details of what
versions of PostgreSQL and operating system you are using as well as
hardware configuration.


- Andrew



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