On 8/21/06, Tom Lane <tgl@sss.pgh.pa.us> wrote: Hmph ... it certainly appears to be choosing the wrong index in the
second case. I wonder why --- can you show the relpages and reltuples
stats from pg_class for these indexes?
I'm personally not aware how to do that, perhaps Alban will (tell me how to) do that tomorrow.
It might be interesting also to examine the output of just
explain select * from mm_insrel_table where dnumber=558332 and dir<>1
with different subsets of these indexes in place. I'd like to see what
it's deriving as the cost estimates for these indexes. If you can get
an EXPLAIN selecting each one of the indexes, that would help diagnose
what's going on.
Ok. Did that (with your trick, thanks!). The output is attached to this e-mail. The script I used to drop the indexes dropped them in the order it was using them (partially by accident, partially because I assumed it would work in that order).
I'm not sure if you want to see more permutations, if so please tell me.
BTW, what PG version is this exactly?
regards, tom lane
Regards,
Wessel van Norel
