Re: mis-estimation on data-warehouse aggregate creation - Mailing list pgsql-performance

On Tue, 16 Nov 2004, Simon Riggs wrote:

> The join condition has so many ANDed predicates that we assume that this
> will reduce the selectivity considerably. It does not, and so you pay
> the cost dearly later on.
>

Yes, that makes a lot of sense.  Without some incredibly good cross-column
statistics there is no way it could expect all of the rows to match.
Thanks for the analysis.

Kris Jurka