Re: MultiXact\SLRU buffers configuration

29 окт. 2020 г., в 04:32, Tomas Vondra <tomas.vondra@2ndquadrant.com> написал(а):

It's not my intention to be mean or anything like that, but to me this
means we don't really understand the problem we're trying to solve. Had
we understood it, we should be able to construct a workload reproducing
the issue ...

I understand what the individual patches are doing, and maybe those
changes are desirable in general. But without any benchmarks from a
plausible workload I find it hard to convince myself that:

(a) it actually will help with the issue you're observing on production

and 
(b) it's actually worth the extra complexity (e.g. the lwlock changes)


I'm willing to invest some of my time into reviewing/testing this, but I
think we badly need better insight into the issue, so that we can build
a workload reproducing it. Perhaps collecting some perf profiles and a
sample of the queries might help, but I assume you already tried that.