tailieunhanh - Overview of Oracle9i Database Performance Tuning

After completing this lesson, you should be able to do the following: Define the roles associated with the database tuning process Describe the dependencies between tuning in different development phases Describe service level agreements Identify tuning goals Identify common tuning problems Employ tuning activities during development and production Balance performance and safety trade-offs | Overview of Oracle9i Database Performance Tuning Objectives After completing this lesson, you should be able to do the following: Define the roles associated with the database tuning process Describe the dependencies between tuning in different development phases Describe service level agreements Identify tuning goals Identify common tuning problems Employ tuning activities during development and production Balance performance and safety trade-offs Tuning Questions Who tunes? Application designers Application developers Database administrators System administrators What to tune? How much tuning? Tuning Questions Who Tunes? Everyone involved with the Oracle system (system architects, designers, developers, and database administrators) should think about performance. If problems develop, it is usually the database administrator (DBA) who makes the first attempt at resolving them, thus the DBA should have an accurate overview of all the applications, and their interaction with each . | Overview of Oracle9i Database Performance Tuning Objectives After completing this lesson, you should be able to do the following: Define the roles associated with the database tuning process Describe the dependencies between tuning in different development phases Describe service level agreements Identify tuning goals Identify common tuning problems Employ tuning activities during development and production Balance performance and safety trade-offs Tuning Questions Who tunes? Application designers Application developers Database administrators System administrators What to tune? How much tuning? Tuning Questions Who Tunes? Everyone involved with the Oracle system (system architects, designers, developers, and database administrators) should think about performance. If problems develop, it is usually the database administrator (DBA) who makes the first attempt at resolving them, thus the DBA should have an accurate overview of all the applications, and their interaction with each other, on the database. What to Tune? The best practice in tuning is careful design of systems and applications. The majority of performance gains are realized by tuning the application. You are less likely to encounter performance problems if: The hardware can meet user demands Your Oracle database is carefully designed Your application developers write efficient SQL programs The database is monitored on a regular basis, looking for bottlenecks that affect performance Tuning Questions (continued) How Much Tuning? The effect of your tuning should be visible to the user base. For this reason there are basically two reasons for tuning the database: Increase the speed of a statement by shortening the response time Provide high throughput scalability at a comparable response time Both reasons often have the same goals: Obtain as few Oracle blocks as possible to resolve the user’s demand Cache frequently used items in memory The database can be tuned in response to an existing problem or because