[indigo945]

Would you argue that automatic scalar-ism is also flawed, and the query

    SELECT a FROM aa;

should have an explicit grouping, like

    SELECT a FROM aa GROUP BY id;

?

After all, when you think about it, it's really not the aggregate functions that break expectations, it's the scalars. Of the four combinations of having or not having an explicit `GROUP BY` and having or not having an aggregate function, three of them have the unsurprising behavior of returning exactly one row per grouping.

    -- aggregate function and group by - one single result per grouping
    SELECT sum(a) FROM aa GROUP BY a; --or
    SELECT sum(a) FROM aa GROUP BY ();


    -- no aggregate function, but a group by - one single result per grouping
    SELECT a FROM aa GROUP BY a;

    -- just aggregate function, but no group by - one single result per (single, implicit) grouping
    SELECT sum(a) FROM aa;

But then, when you have neither an aggregate function nor an explicit `GROUP BY`, it breaks expectations:

    -- no aggregate function, no group by - one result row per row 
    -- in the source set, even though there should be only one big implicit group
    SELECT a FROM aa;

Therefore, I propose that the next SQL standard should introduce a new `GROUP BY INDIVIDUAL ROW` keyword, that henceforth all "scalar" queries MUST use in order to have consistent behaviour with the rest of the language.

[marcosdumay]

What is flawed is not that there is an implicit grouping on all queries. It's that the implicit grouping changes, depending on a set of rules that consider stuff written in several places that are not explicitly related to it.

You are asking if it makes sense to have an implicit grouping at all; it very obviously absolutely does. And grouping by individual row is the very obvious default. But I do totally support adding that keyword expressing the default. All defaults should be expressible.