On Feb 21, 2012, at 15:01, Tom Lane 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.
And hashtext *has* changed across versions, which is why Peter Eisentraut published a version-independent hash function
library:https://github.com/petere/pgvihash
Michael Glaesemann
grzm seespotcode net