Re: strange explain

"Zeugswetter Andreas SB SD" <ZeugswetterA(at)spardat(dot)at> writes:
>> tour=# explain analyze select * from tours where
>> ( operator_id in (2,3,4,5,7) and type_id = 4 ) or
>> ( operator_id = 8 and type_id = 3);

> Actually this plan looks very strange to me. One would expect it to only use
> type_idx twice (in lack of a better index (type_id, operator_id)).
> Seems there is room for another performance improvement here :-)

Yeah, this demonstrates that reducing the quals to canonical form isn't
always the best thing to do.

Or maybe we could just look for duplicate indexqual conditions at the
end of the process?

regards, tom lane