"Kevin Grittner" <Kevin(dot)Grittner(at)wicourts(dot)gov> writes:
> What's up with the sort of _accrged7200 (in the slower plan) taking
> in 3.5 million rows and putting out 1 row? There's something there
> I'm not understanding.
It's under a merge join, so what probably happened is that the first
row from that side had a larger key than any row from the other side.
A mergejoin will never bother to look at the remaining rows in such
a case.
regards, tom lane