On Sat, Oct 30, 2010 at 6:21 PM, Tom Lane <t...@sss.pgh.pa.us> wrote:
> 3. To hash, apply the element type's hash function to each array > element. Combine these values by rotating the accumulator left > one bit at each step and xor'ing in the next element's hash value. > > Thoughts? In particular, is anyone aware of a better method > for combining the element hash values? > This would make the hash the same for arrays with elements 32 apart swapped. This is what boost does: http://www.systomath.com/include/Boost-1_34/doc/html/boost/hash_combine.html Greetings -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers