Re: Creating GiST Indices?

J Smith <dark_panda@hushmail.com> writes:
> This basically went on for hours. I've tried text_ops based on what I can
> see in the pg_class table and a bunch of other stuff, but I can't create
> GiST indexes. (Or rather, I don't know how to.)

The reason you're not getting anywhere is that there aren't any GiST
operator classes in the standard distribution; thus, no way to apply
the GiST code to any datatype.

The various contrib modules that make use of GiST create custom operator
classes --- and, in many cases, custom datatypes as well for the custom
opclasses to work on.

You're right that this is all very poorly documented.  Making new index
opclasses will probably always be a task for wizards, but it'd be nice
if there were more info in the docs about it :-(.  You can try reading
the presentation in the 7.3 devel docs:
    http://developer.postgresql.org/docs/postgres/xindex.html
but note that that does not apply to prior releases; if you actually
want to try this in a current release, next read
    http://www.ca.postgresql.org/users-lounge/docs/7.2/postgres/xindex.html
to see the ugly manual procedure that CREATE OPERATOR CLASS replaces.

            regards, tom lane