Re: Function performance drops during execution of loop

Thanks a lot for the hint Tom! I've replaced deletes with TRUNCATE and it
gave a performance of 50.950 sec which is twice as fast as the drop temp
table method, with the added benefit of not having to raise the
max_locks_per_transaction.

I also think I can't see the performance decrease pattern anymore, or the
operation is completing before that happens, will generate more data and
try again.

Regards
Seref

On Wed, May 21, 2014 at 4:52 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> Seref Arikan <serefarikan(at)kurumsalteknoloji(dot)com> writes:
> > What may be building up here? I suspect deleting all rows from the temp
> > tables is not really deleting them since this is all happening in a
> > transaction, but it is my uneducated guess only.
>
> I suspect you suspect correctly. Autovacuum does not touch temp tables,
> so it won't help you deal with deleted tuples. Given the usage pattern
> you're describing, I think that using a TRUNCATE rather than
> delete-all-the-rows would help ... but if you're already doing that,
> we need more info.
>
> regards, tom lane
>