BUG #2543: Performance delay acrros the same day

The following bug has been logged online:

Bug reference: 2543
Logged by: Alaa El Gohary
Email address: alaaelgohary(at)bftech(dot)com(dot)eg
PostgreSQL version: 7.4.12
Operating system: FreeBSD 6.0
Description: Performance delay acrros the same day
Details:

A query on the postgresql DB takes about 5 seconds and then it starts to
take more time till it reaches about 60 seconds by the end of the same day.
I tried vacuum but nothing changed the only thing that works is to dump the
DB ,drop and create a new one with the dump taken.
i need to know if there is any way to restore the performance back without
the need for drop and create
cause i can't do this accross the day

On Fri, Jul 21, 2006 at 07:41:02 +0000,
Alaa El Gohary <alaaelgohary(at)bftech(dot)com(dot)eg> wrote:
>
> The following bug has been logged online:

The report below isn't a bug, its a performance question and should have
been sent to pgsql-performance(at)postgresql(dot)org(dot) I am redirecting replies there.

> A query on the postgresql DB takes about 5 seconds and then it starts to
> take more time till it reaches about 60 seconds by the end of the same day.
> I tried vacuum but nothing changed the only thing that works is to dump the
> DB ,drop and create a new one with the dump taken.
> i need to know if there is any way to restore the performance back without
> the need for drop and create
> cause i can't do this accross the day

You most likely aren't vacuuming often enough and/or don't have your FSM
setting high enough.

Hi, Bruno,

Bruno Wolff III wrote:
> On Fri, Jul 21, 2006 at 07:41:02 +0000,
> Alaa El Gohary <alaaelgohary(at)bftech(dot)com(dot)eg> wrote:
>> The following bug has been logged online:
>
> The report below isn't a bug, its a performance question and should have
> been sent to pgsql-performance(at)postgresql(dot)org(dot) I am redirecting replies there.
>
>> A query on the postgresql DB takes about 5 seconds and then it starts to
>> take more time till it reaches about 60 seconds by the end of the same day.
>> I tried vacuum but nothing changed the only thing that works is to dump the
>> DB ,drop and create a new one with the dump taken.
>> i need to know if there is any way to restore the performance back without
>> the need for drop and create
>> cause i can't do this accross the day
>
> You most likely aren't vacuuming often enough and/or don't have your FSM
> setting high enough.

Depending on the PostgreSQL version, it might also be that he suffers
from index bloat. He might look into the manual pages about REINDEX for
a description.

HTH,
Markus
--
Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf. | Software Development GIS

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