Re: using index

From: Jurij Modic <jmodic_at_src.si>
Date: 1998/10/10
Message-ID: <361fa67c.3119854@news.siol.net>#1/1

On 10 Oct 1998 03:53:51 GMT, paulkcng_at_news.netvigator.com (Ng K C Paul) wrote:

>What about ' is null ' and ' is not null '? Will it have the same behaviour
>as ' =" " ' and ' <>" " ' ?

No, ordinary B-tree indexes do not store null values, so "is (not) null" condition will never use indexes. Bitmap indexes are different, they store bitmaps also for null values, so "is null" predicates can use bitmap indexes.

HTH,

--
Jurij Modic <jmodic_at_src.si>
Certified Oracle7 DBA (OCP)
================================================
The above opinions are mine and do not represent
any official standpoints of my employer

Received on Sat Oct 10 1998 - 00:00:00 CDT