Is your SQL optimized?

This is a useful tip to help a DBA figure out if certain SQL has been optimized. It gives information in text and graphic form that shows how it's accessing tables and indexes. It also shows all the objects used in the plan and information about those objects such as tablesize, number of records, and more. It has been tested on DB2 UDB v6,7, 8.

Here are the steps to take:

  1. Put the SQL in a CLP file
  2. Run this command:
    db2 connect to <database>
  3. Run this command:
    db2 set current explain mode explain
  4. Run your SQL:
    db2 -vtf   *.CLP
  5. Run this command:
    db2exfmt -d <database> -1 -g TIC -o outputfile
This will put the explain plan in a text file that you can view and check out.

For More Information

  • Feedback: E-mail the editor with your thoughts about this tip.
  • More tips: Hundreds of free DB2 tips and scripts.
  • Tip contest: Have a DB2 tip to offer your fellow DBAs and developers? The best tips submitted will receive a cool prize -- submit your tip today!
  • Ask the Experts: Our SQL, database design, Oracle, SQL Server, DB2, metadata, and data warehousing gurus are waiting to answer your toughest questions.
  • Forums: Ask your technical DB2 questions--or help out your peers by answering them--in our active forums.
  • Best Web Links: DB2 tips, tutorials, and scripts from around the Web.

This was first published in March 2003

There are Comments. Add yours.

TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to:

Disclaimer: Our Tips Exchange is a forum for you to share technical advice and expertise with your peers and to learn from other enterprise IT professionals. TechTarget provides the infrastructure to facilitate this sharing of information. However, we cannot guarantee the accuracy or validity of the material submitted. You agree that your use of the Ask The Expert services and your reliance on any questions, answers, information or other materials received through this Web site is at your own risk.