On Wed, May 11, 2022 at 12:39:41PM +1200, David Rowley wrote: > I think the sort improvements done in v15 are worth a mention under > General Performance. The commits for this were 91e9e89dc, 40af10b57 > and 697492434. I've been running a few benchmarks between v14 and v15 > over the past few days and a fairly average case speedup is about 25%. > but there are cases where I've seen up to 400%. I think the increase > is to an extent that we maybe should have considered making tweaks in > cost_tuplesort(). I saw some plans that ran in about 60% of the time > by disabling Hash Agg and allowing Sort / Group Agg to do the work.
Is there any reason not to consider it now ? Either for v15 or v15+1. I wonder if this is also relevant. 65014000b35 Replace polyphase merge algorithm with a simple balanced k-way merge. -- Justin
