Hi, On 2016-10-30 00:36:55 -0700, Andres Freund wrote: > It's quite easy to change iteration so we start with the latest item, > and iterate till the first, rather than the other way round. In > benchmarks with somewhat wide columns and aggregation, this yields > speedups of over 30%, before hitting other bottlenecks.
One more point: Over IM Robert commented that it's not guaranteed that itemid order correlates precisely with reverse "tuple data" order. After PageRepairFragmentation() that'll not be the case anymore. That's true, but I suspect in many cases with larger analytics queries the correlation will still be significant, and we also could make it guaranteed with the price of making PageRepairFragmentation() a bit more expensive. 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
