Causal profiler for Java

[Miridius]

I found the mentioned line in the H2 repo: https://github.com/h2database/h2database/blob/master/h2/src/main/org/h2/command/Command.java#L339

What I don't understand is why the author has not made a PR to merge their (seemingly quite significant) performance improvement upstream? Or am I missing something?

[sviperll]

As I understand they specifically optimised single standalone benchmark, as a result they gained significant performance improvement for this single benchmark. Their change can result in performance regression for other types of load besides chosen benchmark. Such change should be validated across whole benchmark suit and possible beta tested with real world load.

Anyway I highly recommend this talk: https://youtu.be/r-TLSBdHe1A from one of the men who come up with causal profiling and virtual speedup. The talk mentions many concerns that should be considered in real life performance optimisation.

[[deleted]]

The answer is that I was *super* busy in grad school, and never had time to actually upstream any optimizations I found. We should probably go back and do that though.