Re: 8.4 open item: copy performance regression?

On Thu, Jun 18, 2009 at 05:20:08PM -0400, Tom Lane wrote:
> Stefan Kaltenbrunner <stefan@kaltenbrunner.cc> writes:
> > Any objections if I add:
> > http://archives.postgresql.org/pgsql-performance/2009-06/msg00215.php
> > to the (currently empty) list of open items for 8.4?
> 
> I am unable to duplicate any slowdown on this test case.  AFAICT
> 8.4 and 8.3 branch tip are about the same speed; if anything 8.4
> is faster.  Testing on x86_64 Fedora 10 ...
> 
>             regards, tom lane
> 

What is not clear from Stefen's function listing is how the 8.4
server could issue 33% more XLogInsert() and CopyReadLine()
calls than the 8.3.7 server using the same input file. That would
account for the slow down but now why it is happening.

Cheers,
Ken