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Good Nulls, Bad Nulls (H05)

Topic: 2009 NA

Subtopic: Cross Platform DB2 for z/OS & LUW



DATE: 2009-5-13 (09:45 AM - 10:45 AM)
SPEAKERS: John Maenpaa Jr (Health Care Service Corporation)

Nulls allow us to store incomplete views of our data, but how should we really take advantage of them? Should we avoid them and the perception of confusion that surrounds them? Going overboard to include or exclude the use of nulls in a database can lead to serious data integrity issues. There are good uses for nulls and bad uses for nulls. We'll cover example cases nulls are necessary to ensure the business can retrieve the correct answers to their queries, and opposing cases where the use of nulls makes it more difficult to write accurate SQL statements.

EXP. LEVEL: Beginner,Intermediate

OBJECTIVES:

What does a null mean? We'll cover the reasons for using nulls. We'll also discuss good ways to handle nulls where there might be multiple reasons for the null value.

Discussion of good nulls will cover example cases where we really need to have nullable columns in our databases.

Discussion of bad nulls will cover example cases where the use of nulls may be detrimental.

How does development language selection impact our use of nulls? In the early days, COBOL programmers and their DBAs wanted to avoid nulls. What about now?

How do nulls impact application and query performance?



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