On Mon, Aug 17, 2020 at 4:01 AM Thomas Munro <thomas.mu...@gmail.com> wrote: > While writing this email, I checked the archives and discovered that a > couple of other people have complained about this hot spot before and > proposed faster sorts already[2][3], and then there was a wide ranging > discussion of various options which ultimately seemed to conclude that > we should do what I'm now proposing ... and then it stalled.
I saw compactify_tuples() feature prominently in profiles when testing the deduplication patch. We changed the relevant nbtdedup.c logic to use a temp page rather than incrementally rewriting the authoritative page in shared memory, which sidestepped the problem. I definitely think that we should have something like this, though. It's a relatively easy win. There are plenty of workloads that spend lots of time on pruning. -- Peter Geoghegan