Re: proposal: Set effective_cache_size to greater of .conf value, shared_buffers - Mailing list pgsql-hackers

On Wed, Sep 11, 2013 at 12:43:07PM -0300, Alvaro Herrera wrote:
> Bruce Momjian escribió:
> 
> > > So, are you saying you like 4x now?
> > 
> > Here is an arugment for 3x.  First, using the documented 25% of RAM, 3x
> > puts our effective_cache_size as 75% of RAM, giving us no room for
> > kernel, backend memory, and work_mem usage.  If anything it should be
> > lower than 3x, not higher.
> 
> The other argument I see for the 3x value is that it is a compromise.
> People with really large servers will want to increase it; people with
> very small servers will want to reduce it.

Yes, you could make the argument that 2x is the right default,
especially considering work_mem.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com
 + It's impossible for everything to be true. +