Re: maintenance memory vs autovac

Magnus Hagander wrote:
> Tom Lane wrote:

> > It seems like mostly a confusion-generator to me.  Is there any actual
> > evidence that autovac should use a different maintenance_work_mem than
> > other processes?
> 
> The use-case that made me think of that is one with lots of autovac
> workers in a system with lots of small tables in different databases.

Another thing to consider here is that lazy vacuum will scale down its
memory usage depending on table size.

> Turns out I read the documentation for autovac wrong. I understood that
> if I wanted it to look at 1000 databases at once, I needed
> autovac_workers at 1000. Talked a bit offlist with Alvaro and realized
> that's not what it is, but that the documentation is a bit unclear on
> that - will work on fixing that.

Yeah, Rob Treat has also asked me twice about this, so it's probably
worth rewriting.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
The PostgreSQL Company - Command Prompt, Inc.