> It's equivalent to our assumption that distributions of values in > columns in the same table are independent. Making that assumption in > this case would probably result in occasional dramatic speed > improvements similar to the ones we've seen in less complex joins, > offset by just-as-occasional dramatic slowdowns of similar magnitude. In > other words, it will increase the variance of our results.
Under what circumstances do you think that it would produce a dramatic slowdown? I'm confused. I thought the penalty for picking a bad set of values for the in-memory hash table was pretty small. ...Robert -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
