Attention: To align with new corporate security policies, and to match policies adopted by other communities within Oracle, the My Oracle Support Community access requirements will change beginning September 18, 2025. MOSC will now require that member accounts in our community be associated to a *corporate* email address. This means that users with generic domains (such as gmail.com, yahoo.com, and others) will no longer be granted access to the discussion forums and ideas labs. If this policy affects you, act now to change the email address that is associated with your Oracle (and community) account. Alternatively, you can opt to create a new Oracle account that uses your corporate email domain.

Database Tuning (MOSC)

IS NULL lead into Full Table Scan

Aug 23, 2012 8:36PM edited Sep 2, 2012 1:27PM in Database Tuning (MOSC) 11 commentsAnswered

Dear Experts,

One of our SQL is having IS NULL in where condition which is leading that Table into Full Table scan.

Example

select name from emp where eno is null;

We do have an index on eno field but it is doing a full table scan.

How to avoid full table scan and increase the performance.

Regards

Mudhalvan M.M

0

Howdy, Stranger!

To view full details, sign in to My Oracle Support Community.

Don't have a My Oracle Support Community account? Click here to get started.

Category Leaderboard

Top contributors this month