Re: Hash partitioning.

On 06/25/2013 11:52 PM, Kevin Grittner wrote:
> At least until we have parallel
> query execution.  At *that* point this all changes.

Can you elaborate on that, please? I currently have a hard time
imagining how partitions can help performance in that case, either. At
least compared to modern RAID and read-ahead capabilities.

After all, RAID can be thought of as hash partitioning with a very weird
hash function. Or maybe rather range partitioning on an internal key.

Put another way: ideally, the system should take care of optimally
distributing data across its physical storage itself. If you need to do
partitioning manually for performance reasons, that's actually a
deficiency of it, not a feature.

I certainly agree that manageability may be a perfectly valid reason to
partition your data. Maybe there even exist other good reasons. I don't
think performance optimization is one. (It's more like giving the system
a hint. And we all dislike hints, don't we? *ducks*)

Regards

Markus Wanner