Are parameter markers the best course?

Read how parameter markers are the easiest way to implement "host variable"-like processing with dynamic SQL.

Step 2 of 2:

You forgot to provide an Email Address.

This email address doesn’t appear to be valid.

This email address is already registered. Please login.

You have exceeded the maximum character limit.

Please provide a Corporate E-mail Address.
- I agree to TechTarget’s Terms of Use, Privacy Policy, and the transfer of my information to the United States for processing to provide me with relevant information as described in our Privacy Policy.
Please check the box if you want to proceed.
- I agree to my information being processed by TechTarget and its Partners to contact me via phone, email, or other means regarding information relevant to my professional interests. I may unsubscribe at any time.
Please check the box if you want to proceed.

In most of the DB2 manuals, it is recommended to use parameter markers for dynamic SQL statements. If I modify COBOL applications to use parameter markers instead of new literals each time, will it help in improving the overall performance of the applications. Also, if I start using parameter markers, would it be judicious to increase the existing size of EDM pool to make effective use of dynamic statement caching?

Parameter markers are the easiest way to implement "host variable" like processing with dynamic SQL. One of the benefits of using a parameter marker instead of a literal is that DB2 can continue to use the mini-plan in the EDM pool if you are using dynamic statement caching (DSC). For DSC to work, the dynamic SQL statement has to be EXACTLY the same each time it is run. Changing the literal value changes the SQL statement and requires a rebind. Of course, you might want that if you expect the access path to change based on skewed values.

This was last published in May 2005

Have a question for an expert?

Please add a title for your question

Get answers from a TechTarget expert on whatever's puzzling you.

Meet all of our Data Management/Data Warehousing experts

View all Data Management/Data Warehousing questions and answers

SearchBusinessAnalytics

Related Resources

Dig Deeper on IBM DB2 management

Have a question for an expert?

Start the conversation

0 comments

Register

Login

Forgot your password?

Your password has been sent to:

Please create a username to comment.