"Huang, Suya" <Suya(dot)Huang(at)au(dot)experian(dot)com> writes:
> Thank you Tom. But the time spent on scanning table test1 is less than 1 second (91.738 compares to 87.869), so I guess this shouldn't be the issue?
No, the point is that the bad rowcount estimate (and, possibly, lack of
stats about join column contents) causes the planner to pick a join method
that's not ideal for this query.
regards, tom lane