Robert Haas wrote:
> Tom Lane wrote:
>> I don't think that suppressing nulls from an index this way is
>> really very useful. Using a partial index probably eats more
>> planner cycles than you'll save, overall.
>
> If only 1% of the table has non-NULL values in that column, maybe
> not.
We definitely have indexes with less than 1% non-NULL, and we've
found partial indexes to be efficient for them. On the other hand,
I can't think where we do min/max on any of them; so as long as this
regression only affects those aggregates, it won't hurt our shop.
The use case doesn't seem all that far-fetched to me, though.
-Kevin