Re: [PERFORM] 10x faster sort performance on Skylake CPU vs Ivy Bridge

=?utf-8?Q?Felix_Geisend=C3=B6rfer?= <felix@felixge.de> writes:
> I recently came across a performance difference between two machines that surprised me:
> ...
> As you can see, Machine A spends 5889ms on the Sort Node vs 609ms on Machine B when looking at the "Exclusive" time
withexplain.depesz.com [3][4]. I.e. Machine B is ~10x faster at sorting than Machine B (for this particular query). 

I doubt this is a hardware issue, it's more likely that you're comparing
apples and oranges.  The first theory that springs to mind is that the
sort keys are strings and you're using C locale on the faster machine but
some non-C locale on the slower.  strcoll() is pretty darn expensive
compared to strcmp() :-(

            regards, tom lane