This textbook is the first volume of a two-volume set devoted to the subject of Oracle database server and Oracle data warehouse performance tuning. This first volume provides crucial background information about database performance statistics, metrics and baselines. An enormous amount of performance data is generated and presented by the self-monitoring Oracle database, but the meaning and usefulness of the data is not always obvious. Common questions are: What exactly should I be looking for in amongst all this data? What is the meaning of the performance statistics presented? What conclusions should one reach based upon what is observed and what specific tuning actions should be considered? Therefore, this first volume helps one to assess the current performance of the database or the data warehouse, to identify whether or not there is a serious problem, and if so to isolate which areas of the database should be tuned and which tuning techniques might be considered. This textbook will at times include an in-depth discussion of some internal database operations where these are relevant to assessing database performance. Among the specific subjects discussed within this textbook are: How database performance tuning, SQL statement and application tuning, and the overall systems infrastructure configuration contribute to the performance of database installations; contrast online transaction processing applications with data warehouse activity; consider the systems components that interact with a database installation within multi-tiered systems architectures commonly in use today; review the top 10-database configuration mistakes which contribute towards poor performance; review the top 3 host system performance issues found on database servers; host system components that influence database performance, such as operating systems like Linux, processor capabilities and input/output devices; understanding system read and write internals, such as the difference between small reads and writes versus large reads and writes, asynchronous input/output versus synchronous input/output; review the database performance assessment and performance tuning facilities built into the Oracle database server; understanding the benefit of database performance statistics, metrics, alerts, thresholds and baselines; using the Enterprise Manager real-time performance monitors to immediately assess current database performance; interpreting database operational statistics, wait events and time model statistics to assess database performance and identify processing bottlenecks and constraints. The second volume of this textbook set then provides tuning techniques and remedies that can be applied to address specific problems commonly found, such as the performance bottlenecks demonstrated in this textbook.
