On Tue, Oct 24, 2017 at 5:00 PM, Andres Freund <and...@anarazel.de> wrote: > On 2017-10-24 12:43:12 +0530, amul sul wrote: >> I tried to get suggested SMHasher[1] test result for the hash_combine >> for 32-bit and 64-bit version. >> >> SMHasher works on hash keys of the form {0}, {0,1}, {0,1,2}... up to >> N=255, using 256-N as the seed, for the hash_combine testing we >> needed two hash value to be combined, for that, I've generated 64 >> and 128-bit hash using cityhash functions[2] for the given smhasher >> key then split in two part to test 32-bit and 64-bit hash_combine >> function respectively. Attached patch for SMHasher code changes & >> output of 32-bit and 64-bit hash_combine testing. Note that I have >> skipped speed test this test which is irrelevant here. >> >> By referring other hash function results [3], we can see that hash_combine >> test results are not bad either. >> >> Do let me know if current testing is not good enough or if you want me to do >> more testing, thanks. > > This looks very good! Both the tests you did, and the results for > hash_combineXX. I therefore think we can go ahead with that formulation > of hash_combine64? >
Thanks, Andres. Yes we can, I've added your suggested hash_combine64 in the latest patch[1]. Regards, Amul 1] https://postgr.es/m/CAAJ_b97R2rJinGPAVmZZzpNV%3D-5BgYFxDfY9HYdM1bCYJFGmQw%40mail.gmail.com -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers