Re: Does not use index on query using "field is null"?

=?ISO-8859-1?Q?Bj=F8rn?= T Johansen <btj@havleik.no> writes:
> I have a query that looks like this...:
> select * from table where field is null

> And when I run explain, it tells me that it uses seq scan... Is this because pg thinks that seq scan is as fast as
usingindexes or because using index on "is null" queries does 
> not work?

What PG version?  Releases before 8.3 do not think that IS NULL is an
indexable condition.

            regards, tom lane