On Mon, Feb 23, 2015 at 11:17 AM, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: > So while it's true that for the 3rd query we get much worse results > compared to the other queries (i.e. we don't get >400% speedup but ~3% > slowdown compared to master), it's true that master performs > exceptionally well for this query with small datasets. Once we get to 2M > rows, the master performance drops significantly but cost-model keeps > the performance characteristics and the speedup jumps back to ~700% > which is nice. > > These numbers are for the 'ASC + unsorted row' test, but I do get > exactly the same pattern for the 'random' tests done previously.
Yeah. Looks like you're comparing a case where the old cost model did the right thing anyway (i.e. used abbreviation). The difference would then be entirely explainable as noise. Right? > It would be nice if we could address the 3% regression for the last > query, but I guess it's not a big deal. The numbers in general are > absolutely impressive. Kudos. Thanks. -- Peter Geoghegan -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
