"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.
regards, tom lane