Re: [HACKERS] Performance while loading data and indexing

Shridhar Daithankar wrote:
>
> On 26 Sep 2002 at 19:05, Martijn van Oosterhout wrote:
<snip>
> > fsync IIRC only affects the WAL buffers now but it may be quite expensive,
> > especially considering it's running on every transaction commit. Oh, your
> > WAL files are on a seperate disk from the data?
>
> No. Same RAID 5 disks..

Not sure if this is a good idea. Would have to think deeply about the
controller and drive optimisation/load characteristics.

If it's any help, when I was testing recently with WAL on a separate
drive, the WAL logs were doing more read&writes per second than the main
data drive. This would of course be affected by the queries you are
running against the database. I was just running Tatsuo's TPC-B stuff,
and the OSDB AS3AP tests.

> I guess we forgot to monitor system parameters. Next on my list is running
> vmstat, top and tuning bdflush.

That'll just be the start of it for serious performance tuning and
learning how PostgreSQL works. :)

<snip>
> Thanks once again...
> Bye
> Shridhar

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