On 21 February 2012 20:01, Tom Lane <tgl@sss.pgh.pa.us> wrote:
> "David E. Wheeler" <david@justatheory.com> writes:
>> Is there a reason that hashtext() and friends are not documented?
>
> Yes. They are internal functions that exist for the convenience of the
> system, not for users. We've discussed this before, and decided that
> we don't want people to rely on them continuing to have exactly the
> current behavior. One example of a possible future change is to widen
> the results from 4 bytes to 8.
My pg_stat_statements normalisation patch actually extends the
underlying hash_any() function to support 8 byte results, exactly as
currently anticipated by comments above that function, while supplying
a compatibility macro that is used by existing hash_any() clients.
--
Peter Geoghegan http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training and Services