Re: [Review] Re: minor patch submission: CREATE CAST ... AS EXPLICIT

On Sat, Jun 22, 2013 at 9:16 AM, Cédric Villemain
<cedric(at)2ndquadrant(dot)com> wrote:
> patch is in unified format and apply on HEAD.
> patch contains documentation, however I believe 'AS IMPLICIT' is a PostgreSQL
> extension with special behavior and 'AS EXPLICIT' respect the standard except
> that PostgreSQL adds only the expression 'AS EXPLICIT' (it is also the default
> in the standard).

I object to this patch. This patch a new keyword, EXPLICIT, for
reasons that are strictly cosmetic. Everything that you can do with
this patch can also be done without this patch. It is not a good idea
to slow down parsing of every SQL statement we have just so that
someone can write CREATE CAST .. AS EXPLICIT. Granted, the parsing
slowdown for just one keyword is probably not noticeable, but it's
cumulative with every new keyword we add. Adding them to support new
features is one thing, but adding them to support purely optional
syntax is, I think, going too far.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company