Re: Re: Heaps of read() syscalls by the postmaster

I attac perl script which I run to benchmark postgres.
NOTICE: you should create 'pgtest' database.
It uses DBI, DBD::Pg and Benchmark modules.
There are obvious parameters you can play with.

Regards,

Oleg

On Fri, 19 May 2000, Tom Lane wrote:

> Date: Fri, 19 May 2000 14:46:13 -0400
> From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
> To: Matthias Urlichs <smurf(at)noris(dot)net>
> Cc: pgsql-hackers(at)postgresql(dot)org
> Subject: Re: [HACKERS] Re: Heaps of read() syscalls by the postmaster
>
> "Matthias Urlichs" <smurf(at)noris(dot)net> writes:
> > NB: The same benchmark revealed that CREATE TABLE (or maybe it's CREATE
> > INDEX) leaks about 2k of memory.
>
> Following up on this other point: this could simply be the new table's
> relcache entry (2K seems high though). Currently the relcache doesn't
> have any procedure for discarding uninteresting entries, so once a
> table is referenced by a backend that relcache entry will be there until
> the backend quits or has some specific reason for flushing the entry.
>
> I wouldn't expect a CREATE TABLE / DELETE TABLE cycle to show any memory
> leak, since the DELETE would flush the relcache entry. But creating a
> few thousand tables in a row would start to eat up memory a little bit.
> What is the benchmark doing exactly?
>
> We could add a mechanism for aging relcache entries out of the cache
> when they haven't been touched recently, but so far it hasn't seemed
> worth the trouble...
>
> regards, tom lane
>

_____________________________________________________________
Oleg Bartunov, sci.researcher, hostmaster of AstroNet,
Sternberg Astronomical Institute, Moscow University (Russia)
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(095)939-16-83, +007(095)939-23-83