On 2017-09-21 15:51:54 -0500, Jim Van Fleet wrote: > Not to beat on a dead horse, or anything, but this fix was frowned upon > because in one environment (one socket) it was 6% down and over 15% up in > the right environment (two sockets).
> So, why not add a configuration parameter which specifies the number of > parts? Default is 1 which would be "exactly" the same as no parts and > hence no degradation in the single socket environment -- and with 2, you > get some positive performance. Several reasons: - You'd either add a bunch of branches into a performance critical parts, or you'd add a compile time flag, which most people would be unable to toggle. - It'd be something hard to tune, because even on multi-socket machines it'll be highly load dependant. E.g. workloads that largely are bottlenecked in a single backend / few backends will probably regress as well. FWIW, you started a new thread with this message, that doesn't seem helpful? Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
