On Sun, Apr 19, 2020 at 11:24:38AM -0300, Ranier Vilela wrote: >Hi, >strlen it is one of the low fruits that can be harvested. >What is your opinion? >
That assumes this actually affects/improves performance, without any measurements proving that. Considering large number of the places you modified are related to DDL (CreateComment, ChooseIndexColumnNames, ...) or stuff that runs only once or infrequently (like the changes in PostmasterMain or libpqrcv_get_senderinfo). Likewise, it seems entirely pointless to worry about strlen() overhead e.g. in fsync_parent_path which is probably dominated by I/O.
With code as interconnected as postgres, it is difficult to say that a function, which calls strlen, repeatedly, would not have any gain.
Regarding the functions, I was just being consistent, trying to remove all occurrences, even where, there is very little gain.
Maybe there are places where this would help, but I don't see a reason to just throw away all strlen calls and replace them with something clearly less convenient and possibly more error-prone (I'd expect quite a few off-by-one mistakes with this).
Yes, always, it is prone to errors, but for the most part, they are safe changes. It passes all 199 tests, of course it has not been tested in a real production environment. Perhaps the time is not the best, the end of the cycle, but, once done, I believe it would be a good harvest.
