Something like this:
create table user_history (
user_id int
event_time_stamp timestamp
);I'd like to be able to count the distinct user_ids in this table, even if it were joined to other tables.
-tfo
-- Thomas F. O'Connell Co-Founder, Information Architect Sitening, LLC http://www.sitening.com/ 110 30th Avenue North, Suite 6 Nashville, TN 37203-6320 615-260-0005
On Nov 17, 2004, at 8:52 AM, Stephan Szabo wrote:
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.
---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/docs/faqs/FAQ.html
