Oracle PL/SQL Programming: A Developer's Workbook

Chapter 29. Tuning PL/SQL

Beginner

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29-1.	The statements are: False. A fast program that quickly reaches the wrong answer is still wrong. It’s much more important that a program be correct. False. There is no direct relationship between lines of code and speed (take, for instance, SELECT…INTO). True. Most programs spend 80% of their time executing 20% of the code. The key to significantly improving performance is identifying that 20%. False. Performance is just one property of optimal code. It’s also important that the code be well-structured and readable, and that it follow best practices. True. A program should both yield correct answers and perform well in production. False. Since PL/SQL is stored and executed inside the Oracle database, you must take into account the fact that accessing and running that code competes with other database operations. False. Tuning also involves optimizing the code itself (the algorithm) and the way that code is stored and used in memory. False. There are a number of tools you can use to tune PL/SQL, such as TKPROF, the DBMS_APPLICATION_INFO built-in package, and the PL/SQL code profiler (Oracle8i only). False. While the DBA can help optimize memory utilization or SQL performance, he or she can do almost nothing to improve the performance of a poorly designed algorithm.
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29-2.	(c). You can often get a big performance boost by caching, or saving, frequently used values (e.g., a table of status codes) as PL/SQL variables.
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29-3.	Check to see if Oracle has already ...