Hi, On 2023-11-21 16:42:55 +0700, John Naylor wrote: > I get a noticeable regression in 0002, though, and I think I see why: > > guc_name_hash(const char *name) > { > - uint32 result = 0; > + const unsigned char *bytes = (const unsigned char *)name; > + int blen = strlen(name); > > The strlen call required for hashbytes() is not free. The lack of > mixing in the (probably inlined after 0001) previous hash function can > remedied directly, as in the attached:
I doubt this is a good hashfunction. For short strings, sure, but after that... I don't think it makes sense to reduce the internal state of a hash function to something this small. Greetings, Andres Freund