On Tue, Dec 06, 2005 at 07:52:25PM -0500, Alex Turner wrote:
I would argue that almost certainly won't by doing that as you will create a new place even further away for the disk head to seek to instead of just another file on the same FS that is probably closer to the current head position.
I would argue that you should benchmark it instead of speculating. You are perhaps underestimating the effect of the xfs log. (Ordinarily xfs has great performance, but it seems to be fairly lousy at fsync/osync/etc operations in my benchmarks; my wild speculation is that the sync forces a log flush.) At any rate you're going to have a lot of head movement on any reasonably sized filesystem anyway, and I'm not convinced that hoping that your data will happen to land close to your log is a valid, repeatable optimization technique. Note that the WAL will wander around the disk as files are created and deleted, whereas tables are basically updated in place. Mike Stone
