Re: Making the subquery alias optional in the FROM clause

On Mon, 27 Jun 2022 at 19:43, David G. Johnston
<david(dot)g(dot)johnston(at)gmail(dot)com> wrote:
>
> On Mon, Jun 27, 2022 at 11:25 AM Dean Rasheed <dean(dot)a(dot)rasheed(at)gmail(dot)com> wrote:
>>
>> On Mon, 27 Jun 2022 at 16:12, Julien Rouhaud <rjuju123(at)gmail(dot)com> wrote:
>> >
>> > It doesn't play that well if you have something called subquery though:
>> >
>> > [example that changes a user-provided alias]
>> >
>> > While the output is a valid query, it's not nice that it's replacing a
>> > user provided alias with another one (or force an alias if you have a
>> > relation called subquery).
>>
>> It's already the case that user-provided aliases can get replaced by
>> new ones in the query-deparsing code, e.g.:
>>
>
> Regardless, is there any reason to not just prefix our made-up aliases with "pg_" to make it perfectly clear they were generated by the system and are basically implementation details as opposed to something that appeared in the originally written query?
>
> I suppose, "because we've haven't until now, so why start" suffices...but still doing a rename/suffixing because of query rewriting and inventing one where we made it optional seem different enough to justify implementing something different.
>

I think "pg_" would be a bad idea, since it's too easily confused with
things like system catalogs. The obvious precedent we have for a
made-up alias is "unnamed_join", so perhaps "unnamed_subquery" would
be better.

Regards,
Dean