This book is about tuning Oracle databases. Three areas of Oracle Database tuning are data model tuning, SQL code tuning, and physical and configuration tuning. The author began his career as an applications developer, not as a systems or network administrator. As a result, this book is written from an applications rather than an operating system perspective.
Tuning of SQL code is generally cheaper than changing the data model. Physical and configuration tuning involves a search for bottlenecks that often points to SQL code or data model issues. Building an appropriate data model and writing properly performing SQL code can give 100%+ performance improvement. Physical and configuration tuning often gives at most a 25% performance increase.
The role of the workload, including queries and updates, in
physical design was widely recognized. Therefore, at a high level,
the problem of physical database design was - for a given
workload, find a configuration, i.e. a set of indexes that minimize
the cost. However, early approaches did not always agree on what
constitutes a workload, or what should be measured as cost for a
given query and configuration.
Papers on physical design of databases started appearing as early