On Fri, 20 Aug 2004 11:12:40 -0400 (EDT), Bruce Momjian wrote:
> Yes, you use a partial index. The 8.0beta1 docs mention this:
>
> Indexes are not used for <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.
Is this because nulls aren't indexed (I'm sure I remember someone
saying that they are, though), or because (null=null) is null rather
than true? If it's the latter, why couldn't an explicit IS NULL test
be allowed to use the index?
--
Peter Haworth pmh@edison.ioppublishing.com
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