Re: proposal: Set effective_cache_size to greater of .conf value, shared_buffers

Merlin,

> I vote 4x on the basis that for this setting (unlike almost all the
> other memory settings) the ramifications for setting it too high
> generally aren't too bad.  Also, the o/s and temporary memory usage as
> a share of total physical memory has been declining over time

If we're doing that, then we should change our general advice on this
setting as well.

Another argument in favor: this is a default setting, and by default,
shared_buffers won't be 25% of RAM.

> (meaning, that if you have a 256gb memory server and follow the advice
> to set to 64gb, your memory for caching is approximately 64gb).

Wait, what?

-- 
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com