On Mon, 2008-01-07 at 14:20 +0100, Markus Schiltknecht wrote: > Why is that? AFAIUI, Segment Exclusion combines perfectly well with > clustering. Or even better, with an upcoming feature to maintain > clustered ordering. Where do you see disadvantages such an optimization > for sequential scans?
Well, as I understood it, this would be some kind of special case of clustering, where the cluster key is expected to be ever increasing in time and new rows would not be randomly distributed over the complete possible range. In theory you could also have each segment in turn be clustered on some other criteria than the partitioning criteria so indexed access could also be better on the main selection criteria which could be different than the partitioning criteria. All this is of course just speculations - but I guess that's what you expected too in this discussion :-) Cheers, Csaba. ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq