Re: Postgres performance and the Linux scheduler

Simon Windsor wrote:
> Can the performance of Postgres be boosted, especially on busy
systems, using the none default
> DEADLINE Scheduler?

I think that mostly depends on your storage.

I personally have made one experience where (after weeks of trying
everything
else) I changed the scheduler from CFQ to deadline and immediately got
about
four times better performance. The storage in this case was a SAN.

I don't have enough experience, but my guess is that the smarter your
storage
is, the less the kernel should try to optimize I/O. I assume that in my
case
the kernel's optimizations (which try to optimize things for a physical
hard drive)
and the SAN's optimizations got in each other's way.

As I think is the case for all performance questions, there cannot be a
certain
answer -- the best thing is for you to try it out and see if it does
something for you.

Yours,
Laurenz Albe