Re: Meeting recap - Logic and Databases with Jeff Davis

On Jun 22, 2008, at 17:16, Jeff Davis wrote:

> I provided a link to the slides for my talk, and in there is a
> complete
> example, in which we start out with no NULLs at all in our data, and
> yet
> still run into precisely this problem. In that particular example, a
> WHERE will *not* solve the problem, because aggregates (other than
> COUNT) return NULL when there are no input rows (which I'd like to
> point
> out is not an "unknown").
>
> http://www.pgcon.org/2008/schedule/events/83.en.html

Right, and your solution there (the workaround for the inconsistency
in the standard) is to use COALESCE() inside your aggregate.

I certainly agree that this is ugly and confusing. I've run into it
myself!

Best,

David