On Tue, Mar 12, 2019 at 2:34 PM Peter Geoghegan <pg@bowt.ie> wrote:
> On Tue, Mar 12, 2019 at 11:32 AM Robert Haas <robertmhaas@gmail.com> wrote:
> > If I wanted to try to say this in fewer words, would it be fair to say
> > that reducing the size of an index by 40% without changing anything
> > else can increase contention on the remaining pages?
>
> Yes.
Hey, I understood something today!
I think it's pretty clear that we have to view that as acceptable. I
mean, we could reduce contention even further by finding a way to make
indexes 40% larger, but I think it's clear that nobody wants that.
Now, maybe in the future we'll want to work on other techniques for
reducing contention, but I don't think we should make that the problem
of this patch, especially because the regressions are small and go
away after a few hours of heavy use. We should optimize for the case
where the user intends to keep the database around for years, not
hours.
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company