First, I forgot to mention - this is 8.2 RC1 I was trying on The suggested change produces an identical 'bad' query plan. The main issue (I think) is that the query node that processes "t1 JOIN t11 ON ..' is not aware of the join condition 't28.s = t1.s'.. even though the value of t28.s (as determined by the inner index scan where t28.o = 'spec') could(should?) theoretically be known to it. If it did, then I imagine it would realize that a nested loop join starting with t1.s = t28.s (which is very selective) would be much cheaper than doing the big merge join. -Aaron On 12/3/06, Jonathan Blitz <jb@xxxxxxxxxxxx> wrote:
How about trying: Select * From (Select * from t28 where t28.0='spec') t28a Left out join (t1 JOIN t11 ON > (t11.o = '<http://example.org>' AND t11.s = t1.o)) ON t28a.s = t1.s In this way, I think, the where clause on t28 would be performed before the join rather than after.
