Re: SSD options, small database, ZFS

Amitabh Kant wrote:
> > The whole memorys speed topic is also much more complicated than any
> > simple explanation can cover.  How many banks of RAM you can use
> > effectively changes based on the number of CPUs and associated chipset too.
> >  Someone just sent me an explanation recently of why I was seeing some
> > strange things on my stream-scaling benchmark program.  That dove into a
> > bunch of trivia around how the RAM is actually accessed on the motherboard.
> >  One of the reasons I keep so many samples on that program's page is to
> > help people navigate this whole maze, and have some data points to set
> > expectations against.  See
https://github.com/gregs1104/**stream-scaling<https://github.com/gregs1104/stream-scaling>forthe code and the samples. 
> >
> > --
> > Greg Smith   2ndQuadrant US    greg@2ndQuadrant.com   Baltimore, MD
> > PostgreSQL Training, Services, and 24x7 Support  www.2ndQuadrant.us
> >
> >
> >
> Greg
>
> On a slightly unrelated note, you had once (
> http://archives.postgresql.org/pgsql-general/2011-08/msg00944.php) said to
> limit shared_buffers max to 8 GB on Linux and leave the rest for OS
> caching. Does the same advice hold on FreeBSD systems too?

Hard to say.  We don't know why this is happening but we are guessing it
is the overhead of managing over one million shared buffers.  Please
test and let us know.

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

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