Re: comparison operators

* Tom Lane (tgl(at)sss(dot)pgh(dot)pa(dot)us) wrote:
> Stephen Frost <sfrost(at)snowman(dot)net> writes:
> > * Andrew Dunstan (andrew(at)dunslane(dot)net) wrote:
> >> I think I'd rather just say "for many data types" or something along
> >> those lines, rather than imply that there is some obvious rule that
> >> users should be able to intuit.
>
> > Perhaps with a link to where the informaiton about which exist is
> > available..? Or a query to get the list?
>
> Queries for this sort of thing are covered in the chapter about index
> opclasses. The basic query would be like

Right, a link to there from this would be useful, imv.

> select opcintype::regtype from pg_opclass where opcmethod = 403 and opcdefault;
>
> but I'm not sure if this is completely useful; it's not obvious for
> example that the "text" opclass is also used for varchar. Another
> point is that some of the operators aren't named in the conventional
> way.

Good point. Hopefully a link over to the index-opclasses.html would be
helpful to users exploring these questions.

Thanks,

Stephen