Re: Insertion to temp table deteriorating over time

I've been trying to reproduce the problem for days now :). I've done pretty
much exactly what you describe below, but I can't reproduce the problem on
any of our lab machines. Something is indeed special in this environment.

Thanks for all your help,

Steve

On 12/15/06, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> "Steven Flatt" <steven(dot)flatt(at)gmail(dot)com> writes:
> > Are the removable rows in pg_class even an issue? So what if 5000-6000
> dead
> > tuples are generated every hour then vacuumed? Performance continues to
> > steadily decline over a few days time. Memory usage does not appear to
> be
> > bloating. Open file handles remain fairly fixed. Is there anything
> else I
> > can monitor (perhaps something to do with the odbc connection) that I
> could
> > potentially correlate with the degrading performance?
>
> At this point I think the most productive thing for you to do is to try
> to set up a self-contained test case that reproduces the slowdown. That
> would allow you to poke at it without disturbing your production system,
> and would let other people look at it too. From what you've said, I'd
> try a simple little program that inserts some data into a temp table,
> truncates the table, and repeats, as fast as it can, using the same SQL
> commands as your real code and similar but dummy data. It shouldn't
> take long to observe the slowdown if it occurs. If you can't reproduce
> it in isolation then we'll know that some other part of your application
> environment is contributing to the problem; if you can, I'd be happy to
> look at the test case with gprof or oprofile and find out exactly what's
> going on.
>
> regards, tom lane
>