Re: rapid degradation after postmaster restart

Six days ago I installed Pg 7.4.1 on Sparc Solaris 8 also.  I am hopeful
that we as well can migrate a bunch of our apps from Oracle.

After doing some informal benchmarks and performance testing for the
past week I am becoming more and more impressed with what I see.

I have seen similar results to what you are describing.

I found that running a full vacuum:

vacuumdb -fza

followed by a checkpoint makes it run fast again.

Try timing the update with and without a full vacuum.

I can't help but wonder if a clean shutdown includes some vacuuming.

Obviously, in a production database this would be an issue.

Please post back what you learn.

Sincerely,
Marty

I have been doing a bunch of informat

Joe Conway wrote:
> I'm trying to troubleshoot a performance issue on an application ported
> from Oracle to postgres. Now, I know the best way to get help is to post
> the schema, explain analyze output, etc, etc -- unfortunately I can't do
> that at the moment. However, maybe someone can point me in the right
> direction to figure this out on my own. That said, here are a few
> details...
>
> PostgreSQL 7.4.1
> bash-2.03$ uname -a
> SunOS col65 5.8 Generic_108528-27 sun4u sparc SUNW,Sun-Fire-280R
>
> The problem is this: the application runs an insert, that fires off a
> trigger, that cascades into a fairly complex series of functions, that
> do a bunch of calculations, inserts, updates, and deletes. Immediately
> after a postmaster restart, the first insert or two take about 1.5
> minutes (undoubtedly this could be improved, but it isn't the main
> issue). However by the second or third insert, the time increases to 7 -
> 9 minutes. Restarting the postmaster causes the cycle to repeat, i.e.
> the first one or two inserts are back to the 1.5 minute range.
>
> Any ideas spring to mind? I don't have much experience with Postgres on
> Solaris -- could it be related to that somehow?
>
> Thanks for any insights.
>
> Joe
>
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