CREATE TRANSFORM syntax (was Re: [PATCH] Add transforms feature)

On Mon, 2013-07-08 at 23:00 -0700, Hitoshi Harada wrote:
> On Sun, Jul 7, 2013 at 12:06 PM, Peter Eisentraut <peter_e(at)gmx(dot)net>
> wrote:
> > On Thu, 2013-07-04 at 02:18 -0700, Hitoshi Harada wrote:
> >> as someone suggested in the previous thread, it might be a variant
> of
> >> CAST. CREATE CAST (hstore AS plpython2u) ? Or CREATE LANGUAGE
> TRANSFORM
> >> might sound better. In either case, I think we are missing the
> discussion
> >> on the standard overloading.
> >
> > LANGUAGE isn't a concept limited to the server side in the SQL
> standard.
> > I could go with something like CREATE SERVER TRANSFORM.
>
> I like it better than the current one.

I had started to work on making this adjustment, but found the result
very ugly. It also created a confusing association with CREATE SERVER,
which is something different altogether.

My next best idea is CREATE TRANSFORM FOR hstore SERVER LANGUAGE plperl,
which preserves the overall idea but still distinguishes server from
client languages.

Comments?