Greg,

> > 1) You have n^2 possible two-column combinations. That's a lot of
> > processing and storage.
>
> Yes, that's the hard problem to solve.  Actually, btw, it's n!, not n^2.

Ooops, bad math.  Andrew pointed out it's actually n*(n-1)/2, not n!.

Also, we could omit columns unlikely to correlate, such as large text 
columns, bytea and numerics with high precisions.  Also, we probably don't 
need to correlate UNIQUE columns inside ... I think.

-- 
--Josh

Josh Berkus
PostgreSQL @ Sun
San Francisco

---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?

               http://www.postgresql.org/docs/faq

Reply via email to