Re: An Idea for planner hints

Perez wrote:
> I thought, from watching the list for a while, that the planner
> statistics needed were known but that how to gather the statistics
> was not?

I think over the course of the discussion we have figured out that we 
would like to have cross-column correlation statistics.  The precise 
mathematical incarnation hasn't been determined yet, as far as I can 
see.  Collecting the statistics thereafter isn't that hard, but there 
needs to be a way to not collect an exponential volume of statistics on 
all column combinations.

-- 
Peter Eisentraut
http://developer.postgresql.org/~petere/