On Mar 6, 2007, at 11:40 AM, Tom Lane wrote:
the *actual* average number of rows scanned is 3773. I'm not sure why this should be --- is it possible that the distribution of keys in symptom_reports is wildly uneven? This could happen if all of the physically earlier rows in symptom_reports contain the same small set of symptom_ids, but the stats don't seem to indicate such a skew.
Hi Tom, you are correct, the distribution is uneven... In the 13k symptom_reports rows, there are 105 distinct symptom_ids. But the first 8k symptom_reports rows only have 10 distinct symptom_ids. Could this cause the problem and would there be anything I could do to address it?
Thanks for all your help, I appreciate it. -Jeff
