Re: Counting Distinct Records

On Tue, 16 Nov 2004, Thomas F.O'Connell wrote:

> Hmm. I was more interested in using COUNT( * ) than DISTINCT *.
>
> I want a count of all rows, but I want to be able to specify which
> columns are distinct.

I'm now a bit confused about exactly what you're looking for in the end.
Can you give a short example?

> That's definitely an interesting approach, but testing doesn't show it
> to be appreciably faster.
>
> If I do a DISTINCT *, postgres will attempt to guarantee that there are
> no duplicate values across all columns rather than a subset of columns?
> Is that right?

It guarantees one output row for each distinct set of column values across
all columns.