Simon Riggs <simon@2ndquadrant.com> writes:
> On Tue, 2006-06-06 at 10:31 -0400, Tom Lane wrote:
>> This discussion is also overlooking
>> the possibility that a partial index is being used for its predicate
> Assuming its possible, of course.
Sure:
regression=# create index tenk1p on tenk1(unique1) where unique2 % 100 = 0;
CREATE INDEX
regression=# explain select * from tenk1 where unique2 % 100 = 0;
QUERY PLAN
----------------------------------------------------------------------
Bitmap Heap Scan on tenk1 (cost=2.10..139.14 rows=50 width=244)
Recheck Cond: ((unique2 % 100) = 0)
-> Bitmap Index Scan on tenk1p (cost=0.00..2.10 rows=50 width=0)
(3 rows)
regards, tom lane