On Tue, Jun 25, 2019 at 11:03 AM James Coleman <jtc331@gmail.com> wrote:
> No, I haven't confirmed that it's called less frequently, and I'd be
> extremely surprised if it were given the diff doesn't suggest any
> changes to that at all.
I must have misunderstood, then. I thought that you were suggesting
that that might have happened.
> If you think it's important enough to do so, I can instrument it to
> confirm, but I was mostly wanting to know if there were any other
> plausible explanations, and I think you've provided one: there *are*
> changes in the patch to memory contexts in tuplesort.c, so if memory
> fragmentation is a real concern this patch could definitely notice
> changes in that regard.
Sounds like it's probably fragmentation. That's generally hard to measure.
--
Peter Geoghegan