Re: hardware performance and some more

On 24 Jul 2003 at 9:42, William Yu wrote:

> As far as I can tell, the performance impact seems to be minimal.
> There's a periodic storm of replication updates in cases where there's
> mass updates sync last resync. But if you have mostly reads and few
> writes, you shouldn't see this situation. The biggest performance impact
> seems to be the CPU power needed to zip/unzip/encrypt/decrypt files.

Can you use WAL based replication? I don't have a URL handy but there are
replication projects which transmit WAL files to another server when they fill
in.

OTOH, I was thinking of a simple replication theme. If postgresql provides a
hook where it calls an external library routine for each heapinsert in WAL,
there could be a simple multi-slave replication system. One doesn't have to
wait till WAL file fills up.

Of course, it's upto the library to make sure that it does not hold postgresql
commits for too long that would hamper the performance.

Also there would need a receiving hook which would directly heapinsert the data
on another node.

But if the external library is threaded, will that work well with postgresql?

Just a thought. If it works, load-balancing could be lot easy and near-
realtime..

Bye
Shridhar

--
We fight only when there is no other choice. We prefer the ways ofpeaceful contact. -- Kirk, "Spectre of the Gun", stardate 4385.3