Re: Slow count(*) again...

Dan Harris wrote:
> I'm not sure how to figure out what version of XFS we're on.. but it's 
> Linux kernel 2.6.24-24 x86_64 on Ubuntu Server 8.04.3.  Postgres 
> version 8.3

There's the kernel side support that matches your kernel, as well as the 
xfsprogs package.  The latter is where a lot of distributions haven't 
kept up with upstream changes, and where I suspect the defragmenter bug 
you ran into is located at.

Hardy ships with 2.9.4-2:  http://packages.ubuntu.com/hardy/xfsprogs

The work incorporating a more stable XFS into RHEL started with xfsprogs 
3.0.1-6 going into Fedora 11, and 3.1.X would represent a current 
release.  So your Ubuntu kernel is two major improvement releases 
behind, 3.0 and 3.1 were the upgrades to xfsprogs where things really 
got going again making that code modern and solid.  Ubuntu Lucid 
switched to 3.1.0, RHEL6 will probably ship 3.1.0 too.

-- 
Greg Smith, 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services and Support  www.2ndQuadrant.us
Author, "PostgreSQL 9.0 High Performance"    Pre-ordering at:
https://www.packtpub.com/postgresql-9-0-high-performance/book