Re: Auto-tuning work_mem and maintenance_work_mem

On Wed, Oct  9, 2013 at 04:40:38PM +0200, Pavel Stehule wrote:
>     Effectively, if every session uses one full work_mem, you end up with
>     total work_mem usage equal to shared_buffers.
> 
>     We can try a different algorithm to scale up work_mem, but it seems wise
>     to auto-scale it up to some extent based on shared_buffers.
> 
> 
> In my experience a optimal value of work_mem depends on data and load, so I
> prefer a work_mem as independent parameter.

But it still is an independent parameter.  I am just changing the default.

> maintenance_work_mem can depend on work_mem ~ work_mem * 1 * max_connection / 4

That is kind of hard to do because we would have to figure out if the
old maintenance_work_mem was set from a default computation or by the
user.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + Everyone has their own god. +