Re: create language ... if not exists

Tom Lane wrote:
> Heikki Linnakangas <heikki@enterprisedb.com> writes:
>> The way we've solved this problem for other CREATE commands is to add
>> "OR REPLACE" option, instead of "IF NOT EXISTS". We should do the same here.
>
> If we're willing to consider a solution that is specific to CREATE
> LANGUAGE (as opposed to implementing IF NOT EXISTS across-the-board,
> which might happen someday) what I'd suggest is just incorporating
> the behavior directly into the abbreviated (no parameters) form of
> CREATE LANGUAGE.  If the language already exists and has the same
> properties specified in pg_pltemplate, don't raise an error.  Give
> a notice maybe.

Why not implement "OR REPLACE" like for other things? Still seems the
most consistent behavior to me.

You might want to get the error if the language already exists, which
your proposal wouldn't allow. And it wouldn't help with languages
without a pg_pltemplate entry.

--
   Heikki Linnakangas
   EnterpriseDB   http://www.enterprisedb.com