On Wed, Feb 22, 2017 at 8:08 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
Bernd Helmle <mailings@oopsware.de> writes: >> From time to time, especially during migration projects from Oracle to > PostgreSQL, i'm faced with people questioning why the alias in the FROM > clause for subqueries in PostgreSQL is mandatory. The default answer > here is, the SQL standard requires it.
Indeed. When I wrote the comment you're referring to, quite a few years ago now, I thought that popular demand might force us to allow omitted aliases. But the demand never materialized. At this point it seems clear to me that there isn't really good reason to exceed the spec here. It just encourages people to write unportable SQL code.
I'll contribute to the popular demand aspect but given that the error is good and the fix is very simple its not exactly a strong desire.
My code is already unportable since I choose to use "::" for casting - and I'm sure quite a few other PostgreSQL-specific things - so the portability aspect to the argument is already thin for me and moreso given other DBMSes already relax the requirement.
