Re: [HACKERS] [PATCHES] Proposed patch: synchronized_scanningGUCvariable

2008-01-29 Thread Stephen Denne
Jeff Davis wrote > > Well clusteredness is used or could be used for a few > different heuristics, > > not all of which this would be quite as well satisfied as > readahead. But for > > Can you give an example? Treating a file as a circular structure does > not impose any significant cost that I

Re: [HACKERS] [PATCHES] Proposed patch: synchronized_scanningGUCvariable

2008-01-29 Thread Heikki Linnakangas
Jeff Davis wrote: On Mon, 2008-01-28 at 23:13 +, Heikki Linnakangas wrote: It's a good point that we don't want pg_dump to screw up the cluster order, but that's the only use case I've seen this far for disabling sync scans. Even that wouldn't matter much if our estimate for "clusteredness