Michael Stone wrote:
On Sat, Jul 22, 2006 at 10:26:53AM -0700, Craig A. James wrote:
This causes massive file-system activity and flushes all files that
the kernel has cached. If you run this between each Postgres test
(let it run for a couple minutes), it gives you an apples-to-apples
comparison between successive benchmarks, and eliminates the effects
of caching.
Assuming a system with small ram or an unusually large system
installation. Unmounting is a much more realiable mechanism.
Indeed, but it only works if you can. For example, in my small-ish installation, my WAL and system tables are mounted on the root disk. Or someone might not have super-user access.
Craig
