Re: what is a "working set" ?

On Mon, Apr 23, 2012 at 04:43:25PM -0700, Aleksey Tsalolikhin wrote:
> Hi.  I'm trying to find a definition of "working set", it seems
> important for performance tuning, but I cannot find a PostgreSQL
> document defining it.

That is a great question, and I plan to write a blog about it soon.
Working set is from the mainframe days and tries to represent how much
data you "touch" during a specified period of time, e.g. a 5-minute
working set is the amount of data you typically access (and maybe write)
in a 5-minute period.  It is _very_ hard to get that information right
now from Postgres, and getting that information for a typical Unix
process isn't easy either.

--
  Bruce Momjian  <bruce@momjian.us>        http://momjian.us
  EnterpriseDB                             http://enterprisedb.com

  + It's impossible for everything to be true. +