Sorry for fat-fingering the previous reply -- I wanted to add:
On Fri, 2007-04-27 at 10:02 -0400, Tom Lane wrote:
> Perhaps a sufficiently robust way would be to form the hash as the
> XOR of each supplied digit, circular-shifted by say 3 times the
> digit's weight.
The only objection I have to this is that it means we need to have
another hash function in the backend. The Jenkins hash we use in
hash_any() has been studied and we can have at least some confidence in
its collision-resistance, etc.
Anyway, attached is a revised version of the hash_any()-based patch.
-Neil