On Tue, Jun 04, 2019 at 01:49:23PM -0400, Stephen Frost wrote:
Greetings,
* Melanie Plageman (melanieplage...@gmail.com) wrote:
Peter and I implemented this small (attached) patch to extend
abbreviated key compare sort to macaddr8 datatype (currently supported
for macaddr).
Nice.
I think that that seems like an improvement. I was thinking of
registering this patch for the next commitfest. Is that okay?
Sure.
I was just wondering what the accepted way to test and share
performance numbers is for a small patch like this. Is sharing DDL
enough? Do I need to use pg_bench?
Detailed (enough... doesn't need to include timing of every indivudal
query, but something like the average timing across 5 runs or similar
would be good) results posted to this list, with enough information
about how to reproduce the tests, would be the way to go.
The idea is to let others also test and make sure that they come up with
similar results to yours, and if they don't, ideally have enough
information to narrow down what's happening / what's different.
Yeah, there's no "approved way" to do performance tests the contributors
would have to follow. That applies both to tooling and how detailed the
data need/should be. Ultimately, the goal is to convince others (and
yourself) that the change is an improvement. Does a simple pgbench
script achieve that? Cool, use that. Do you need something more complex?
Sure, do a shell script or something like that.
As long as others can reasonably reproduce your tests, it's fine.
For me, the most critical part of benchmarking a change is deciding what
to test - which queries, data sets, what amounts of data, config, etc.
For example, the data set you used has ~12k rows. Does the behavior
change with 10x or 100x that? It probably does not make sense to go
above available RAM (the I/O costs are likely to make everything else
mostly irrelevant), but CPU caches may matter a lot. Different work_mem
(and maintenance_work_mem) values may be useful too.
regards
--
Tomas Vondra http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
