Re: Regression in IN( field, field, field ) performance - Mailing list pgsql-hackers

Gregory Stark <stark@enterprisedb.com> writes:
> Tom Lane <tgl@sss.pgh.pa.us> writes:
>> Works fine for me, eg

> I think he's looking for something like:
>  5 IN (col1,col2,col3)
> resulting in a bitmap or of three index scans of three different indexes on
> col1, col2, and col3.

Ah, I see.  It would be easy to make transformAExprIn() generate an OR
tree instead of = ANY(ARRAY[]), if we could figure out the conditions
where an OR tree is superior.  I'm not sure it's easy to tell though.
Is it sufficient to do this when there are Vars on the right side and
none on the left?
        regards, tom lane