ITAGAKI Takahiro <itagaki.takahiro@oss.ntt.co.jp> writes:
> I tested 8.3beta4 with DBT-3 (TPC-H) and found unstable selection of plans.
> Planner randomly selected two types of plans (A, B) when I repeated EXPLAIN.
Are you sure the statistics weren't changing underneath you (due to
auto-vacuum or auto-analyze)?
regards, tom lane