One of the most important challenges faced by Oracle database administrators and Oracle developers is the need to tune SQL statements so that they execute efficiently. Poorly tuned SQL statements are one of the leading causes of substandard database performance and poor response time. SQL statements that perform poorly result in frustration for users, and can even prevent a company from serving its customers in a timely manner.
In this book, Mark Gurry shares his in-depth knowledge of Oracle's SQL statement optimizers. Mark's knowledge is the result of many hard-fought tuning battles during his many years of providing Oracle tuning services to clients. Mark provides insights into the workings of the rule-based optimizer that go well beyond what the rules tell you. Mark also provides solutions to many common problems that occur with both the rule-based and cost-based optimizers.
In addition to the specific problem/solution scenarios for the optimizers, Mark provides a number of handy SQL tuning tips. He discusses the various optimizer hints, telling you when they can be used to good effect. Finally, Mark discusses the use of the DBMS_STATS package to manage database statistics, and the use of outlines to specify execution plans for SQL statements in third-party applications that you can't otherwise modify.
As a database administrator on a financial IMS project about eight years ago, Mark Gurry was asked to investigate his company's database direction for the next five years. The number of users was up to 950, the cost of maintaining the mainframes was huge, and he'd heard about relational databases and downsizing. After much investigation, he chose Oracle, and has stuck with the system ever since. He has worked as Manager of Computing and Network Services, senior database administrator, senior Oracle technical support, and other jobs. He now has a small consulting company called New Age Consultants. Mark has worked for many large organizations and is currently working for Telecom Australia, the largest computer site in Australia and one of the largest in the world. He has also spoken on tuning at Oracle user group meetings and has given internal tuning courses at several of his larger client sites. He has been a senior team member on award-winning systems that have been developed using Oracle.