Re: SQL feature requests

Michael Glaesemann wrote:
>
> On Aug 23, 2007, at 14:25 , Tom Lane wrote:
>
>> Josh Berkus <josh@agliodbs.com> writes:
>>> I just don't see the ability to omit the alias in a query with only one
>>> subquery (the only circumstances under which it would be safe to do so) 
>>> as
>>> any significant gain in fuctionality.
>>
>> Why do you think it'd be restricted to only one subquery?
>>
>> As long as you take care that the subquery's column names don't match
>> any other ones in the query, you don't *need* an alias for it ---
>> there'll be no need to qualify the column names.  This extends just
>> fine to multiple subqueries.
>
> How about something like gensym? One alias you could always use and be 
> guaranteed it would give a unique value. Still provide the alias, but don't 
> have to think about name collisions.

It is dangerous to provide a synthetic name; if the standard ever gets
modified to support alias-less subqueries, they would likely choose a
different name-generating algorithm, and we would have a
backward-compatibility problem.

Or is that a backwards-compatibility problem?  I remain unsure.

-- 
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support