On Tue, 18 Jun 2019 at 22:34, Tomas Vondra <tomas.von...@2ndquadrant.com> wrote: > > One slightly inconvenient thing I realized while playing with the > address data set is that it's somewhat difficult to set the desired size > of the multi-column MCV list. > > At the moment, we simply use the maximum statistic target for attributes > the MCV list is built on. But that does not allow keeping default size > for per-column stats, and only increase size of multi-column MCV lists. > > So I'm thinking we should allow tweaking the statistics for extended > stats, and serialize it in the pg_statistic_ext catalog. Any opinions > why that would be a bad idea? >
Seems reasonable to me. This might not be the only option we'll ever want to add though, so perhaps a "stxoptions text[]" column along the lines of a relation's reloptions would be the way to go. > I suppose it should be part of the CREATE STATISTICS command, but I'm > not sure what'd be the best syntax. We might also have something more > similar to ALTER COLUMNT, but perhaps > > ALTER STATISTICS s SET STATISTICS 1000; > > looks a bit too weird. > Yes it does look a bit weird, but that's the natural generalisation of what we have for per-column statistics, so it's probably preferable to do that rather than invent some other syntax that wouldn't be so consistent. Regards, Dean
