8.6. Don't Tune a Query

On the asktom web site, I am frequently presented with a long query or a block of code and the simple request to make it go faster. Others want to know how they can do a particular operation in a certain way, where they obviously want to make Oracle behave just like Sybase, Informix, DB2, or some other database. Many times, unless there is some obvious enhancement such as bulk processing, I cannot provide any help until I know what the goal is—what they are trying to achieve with the query.

8.6.1. Understand the Question

When you look at a query, you see a set of requirements. You see joins, predicates, outer joins, and so on. But you need to understand the question being asked. I frequently see constructs like this: