"Tom Lane" <tgl@sss.pgh.pa.us> writes:
> The argument that Heikki actually made was that multiple parallel
> queries could use more of the I/O bandwidth of a multi-disk array
> than recovery could. Which I believe, but I question how much of a
> real-world problem it is. For it to be an issue, you'd need a workload
> that is almost all updates (else recovery wins by not having to
> replicate reads of pages that don't get modified) and the updates have
> to range over a working set significantly larger than physical RAM
> (else I/O bandwidth won't be the bottleneck anyway). I think we're
> talking about an extremely small population of real users.
Of course that describes most benchmarks pretty well...
I think of this as a scalability problem, not so much a sheer speed problem.
If Postgres isn't fast enough for you you should be able to buy a faster
processor or faster disk or faster something to run it faster. The problem
with this situation is that buying a faster raid controller doesn't help you.
-- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's RemoteDBA services!