Re: [HACKERS] A Better External Sort?

OK, change "performance" to "single thread performance" and we
still have a valid starting point for a discussion.

Ron

-----Original Message-----
From: Gregory Maxwell <gmaxwell(at)gmail(dot)com>
Sent: Oct 3, 2005 8:19 PM
To: Ron Peacetree <rjpeace(at)earthlink(dot)net>
Subject: Re: [HACKERS] [PERFORM] A Better External Sort?

On 10/3/05, Ron Peacetree <rjpeace(at)earthlink(dot)net> wrote:
[snip]
> Just how bad is this CPU bound condition? How powerful a CPU is
> needed to attain a DB IO rate of 25MBps?
>
> If we replace said CPU with one 2x, 10x, etc faster than that, do we
> see any performance increase?
>
> If a modest CPU can drive a DB IO rate of 25MBps, but that rate
> does not go up regardless of how much extra CPU we throw at
> it...

Single threaded was mentioned.
Plus even if it's purely cpu bound, it's seldom as trivial as throwing
CPU at it, consider the locking in both the application, in the
filesystem, and elsewhere in the kernel.