> WRT tablespaces: What I'm planning to do, unless somebody has a better
> proposal, is to basically rent two big amazon instances, and run pgbench
> in parallel over N tablespaces. Once with local SSD and once with local
> HDD storage.
Ok.
Not sure how to control that table spaces are actually on distinct
dedicated disks with VMs, but this is the idea.
To emphasize potential bad effects without having to build too large a
host and involve too many table spaces, I would suggest to reduce
significantly the "checkpoint_flush_after" setting while running these
tests.
--
Fabien.