Hi, On 2018-01-24 13:11:22 -0500, Robert Haas wrote: > So for me, the additional hash index tests don't cost anything > measurable and the additional hash join tests cost about a second. I > think this probably accounts for why committers other than you keep > "adding so much time to the regression tests". On modern hardware, > the costs just don't matter.
I very much agree with the general sentiment, but a second of a 25s test certainly isn't nothing. As I've just written a few messages upthread, I think we can hide the overall timing costs to a much larger degree than we're doing, but I don't think we need not pay attention at all. > Now, how much should we care about the performance of software with a > planned release date of 2018 on hardware discontinued in 2001, > hardware that is apparently about 20 times slower than a modern > laptop? Some, perhaps, but maybe not a whole lot. Removing tests > that have found actual bugs because they cost runtime on ancient > systems that nobody uses for serious work doesn't make sense to me. I again agree with the sentiment. One caveat is that old machines also somewhat approximate testing with more instrumentation / debugging enabled (say valgrind, CLOBBER_CACHE_ALWAYS, etc). So removing excessive test overhead has still quite some benefits. But I definitely do not want to lower coverage to achieve it. Greetings, Andres Freund