Re: Slow count(*) again...

On 10/11/10 8:02 PM, Scott Carey wrote:
> would give you a 1MB read-ahead.  Also, consider XFS and its built-in defragmentation.  I have found that a longer
livedpostgres DB will get extreme 
> file fragmentation over time and sequential scans end up mostly random.  On-line file defrag helps tremendously.
>
We just had a corrupt table caused by an XFS online defrag.  I'm scared
to use this again while the db is live.  Has anyone else found this to
be safe?  But, I can vouch for the fragmentation issue, it happens very
quickly in our system.

-Dan