Thread: the eternal tunnig question

Hi, iam running postgresql on two identical dl380 2.4 Xeon with 3gb RAM, i
have recently upgraded one of then from redhat 7.3 (kernel 2.4) to gentoo
(kernel 2.6), at the same time i upgraded postgres from 7.3 to 8.1, im very
disapointed, all the querys are 20-25% slower using the new versions, the
following setting are the same in postgresql.conf


shared_buffers = 10240
work_mem = 5120
max_fsm_pages = 170000
max_fsm_relations = 10000



i havent touched anything else.
However i see a lot of new setting in PG8, is there a online manual for
tunnig these new settings?, may be a need some fine setting here and there.

thanks

mmiranda@americatel.com.sv writes:
> Hi, iam running postgresql on two identical dl380 2.4 Xeon with 3gb RAM, i
> have recently upgraded one of then from redhat 7.3 (kernel 2.4) to gentoo
> (kernel 2.6), at the same time i upgraded postgres from 7.3 to 8.1, im very
> disapointed, all the querys are 20-25% slower using the new versions, the
> following setting are the same in postgresql.conf

You might have forgotten to redo vacuum/analyze after reloading your
data ...

            regards, tom lane

Tom Lane wrote:
> mmiranda@americatel.com.sv writes:
>> Hi, iam running postgresql on two identical dl380 2.4 Xeon with 3gb
>> RAM, i have recently upgraded one of then from redhat 7.3 (kernel
>> 2.4) to gentoo (kernel 2.6), at the same time i upgraded postgres
>> from 7.3 to 8.1, im very disapointed, all the querys are 20-25%
>> slower using the new versions, the following setting are the same in
>> postgresql.conf
>
> You might have forgotten to redo vacuum/analyze after reloading your
> data ...
>
>             regards, tom lane


thanks Tom,
Definitely you're the man around here, vacuum/analyze did the trick

BTW, i found this very interresting link, answered my questions about
tunning,

http://www.varlena.com/varlena/GeneralBits/Tidbits/#performance


bye
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