Roger Leigh <rleigh@codelibre.net> writes:
> I've created a new domain (debversion) derived from TEXT, which
> includes its own operators (< <= = >= > and <>), and also its
> own operator class for BTREE indices.
You can't realistically attach such things to a domain; try making
a separate type, perhaps with an implicit cast to text to allow
use of text operators for other purposes.
Elein was going to look into tweaking the coercion rules so that
functions on domains had a non-negligible chance of being useful,
but we've not heard much about that project lately.
regards, tom lane