Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > + <literal>NULL</> values are not indexed by default.
>
> This is quite incorrect. The nulls *are* indexed (at least in btree
> indexes); the issue is whether there is any way to use the index to
> search for them. I do not think it helps anyone for the documentation
> to get this basic point wrong, even if the distinction is subtle.
OK, docs updated with:
Indexes can not be used with <literal>IS NULL</> clauses by default.
The best way to use indexes in such cases is to create a partial index
using an <literal>IS NULL</> comparison.
--
Bruce Momjian | http://candle.pha.pa.us
pgman@candle.pha.pa.us | (610) 359-1001
+ If your life is a hard drive, | 13 Roberts Road
+ Christ can be your backup. | Newtown Square, Pennsylvania 19073