Re: Improving inferred query column names

On Wed, Feb 22, 2023, 12:40 PM Andres Freund <andres(at)anarazel(dot)de> wrote:

> Hi,
>
> On 2023-02-11 12:47:04 -0800, Vladimir Churyukin wrote:
> > That is a good idea for simple cases, I'm just curious how it would look
> > like for more complex cases (you can have all kinds of expressions as
> > parameters for aggregate function calls).
> > If it works only for simple cases, I think it would be confusing and not
> > very helpful.
>
> I don't think it needs to be perfect to be helpful.
>

It doesn't need to be perfect, but it needs to be consistent. So far you
proposed a rule to replace () with _. What is the plan for expressions, how
to convert them to names (with deduplication I guess?, because there could
be 2 similar expressions mapped to the same name potentially).

> > Wouldn't it make more sense to just deduplicate the names by adding
> > numerical postfixes, like sum_1, sum_2?
>
> That'd be considerably worse than what we do today imo, because any
> reordering
> / added aggregate would lead to everything else changing as well.
>

Ok, that I kinda agree with. Not necessarily worse overall, but worse for
some cases. Well, the proposal above about keeping the names exactly the
same as the full expressions is probably the best we can do then. It will
take care of possible duplications and won't be position-sensitive. And
will be consistent. The only issue is somewhat unusual column names that
you will have to use quotes to refer to. But is that a real issue?

-Vladimir Churyukin

>