Re: Why would writes to pgsql_tmp bottleneck at 1mb/s?

Hmmmm.....

> > As you can see, we're getting a nice 23mb/s peak for WAL (thanks to
> > forcedirectio) and database writes peak at 6mb/s.  However, pgsql_tmp,
> > which is being used heavily, hovers around 1mb/s, and never goes above
> > 1.5mb/s. This seems to be throttling the whole system.
>
> Never mind, I'm a dork.    I accidentally cut the "SET maintenance_work_mem
> = 2000000" out of my config file, and it was running with the default 1024K

Maybe I'm not an idiot (really!)  even with almost 2GB of maintenance_mem, PG
still writes to pgsql_tmp no faster than 2MB/s.    I think there may be an
artificial bottleneck there.  Question is, PostgreSQL, OS or hardware?

Suggestions?

--
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco