Re: anti-join chosen even when slower than old plan

Tom Lane  wrote:
 
> However, you'd have to be spending a lot of time chasing through
> long HOT chains before that would happen enough to make this a
> hotspot...
 
That makes it all the more mysterious, then.  These tables are
insert-only except for a weekly delete of one week of the oldest
data.  The parent table, with the date, is deleted first, then this
table deletes "where not exists" a corresponding parent.  I can't
see how we'd ever have a HOT chain in these tables.
 
Is there anything in particular you'd like me to check?
 
-Kevin