On Sat, Sep 30, 2017 at 12:34 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > Robert Haas <robertmh...@gmail.com> writes: >> How about widening the value to uint64? > > Doesn't really seem like that would guarantee no collisions.
Well, no duh. If you come up with a hash function that maps an infinite domain onto a finite range while guaranteeing no collisions, I will look forward to reading the paper with interest. Assuming, however, that you don't manage to prove all known mathematics inconsistent, what one might reasonably hope to do is render collisions remote enough that one need not worry about them too much in practice. From that point of view, reducing the probability of a collision by several orders of magnitude seems worth doing if (1) the cost isn't too much and (2) the probability of a collision as things stand is significant. I argue that both of those things are probably true. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers