Optimizing Queries

When you submit a SQL statement to the database management system, a lot of work that you don't see gets done. In fact, SQL is considered a nonprocedural language precisely because it does not require the user to specify the steps the system must take to execute the command. Instead, the user simply states what is being sought.

The strength of the nonprocedural approach is the same as its drawback. To state it positively, the system does the work for you. The bad news is that once you're committed to a particular database design, you usually have no choice but to trust the system's intelligence rather than your own.


The part of the database management system responsible for analyzing a SQL statement is called the ...

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