Book Image

Advanced Oracle PL/SQL Developer's Guide (Second Edition) - Second Edition

By : Saurabh K. Gupta
Book Image

Advanced Oracle PL/SQL Developer's Guide (Second Edition) - Second Edition

By: Saurabh K. Gupta

Overview of this book

Oracle Database is one of the most popular databases and allows users to make efficient use of their resources and to enhance service levels while reducing the IT costs incurred. Oracle Database is sometimes compared with Microsoft SQL Server, however, Oracle Database clearly supersedes SQL server in terms of high availability and addressing planned and unplanned downtime. Oracle PL/SQL provides a rich platform for application developers to code and build scalable database applications and introduces multiple new features and enhancements to improve development experience. Advanced Oracle PL/SQL Developer's Guide, Second Edition is a handy technical reference for seasoned professionals in the database development space. This book starts with a refresher of fundamental concepts of PL/SQL, such as anonymous block, subprograms, and exceptions, and prepares you for the upcoming advanced concepts. The next chapter introduces you to the new features of Oracle Database 12c, not limited to PL/SQL. In this chapter, you will understand some of the most talked about features such as Multitenant and Database In-Memory. Moving forward, each chapter introduces advanced concepts with the help of demonstrations, and provides you with the latest update from Oracle Database 12c context. This helps you to visualize the pre- and post-applications of a feature over the database releases. By the end of this book, you will have become an expert in PL/SQL programming and will be able to implement advanced concepts of PL/SQL for efficient management of Oracle Database.
Table of Contents (19 chapters)
Advanced Oracle PL/SQL Developer's Guide Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Oracle Database 11g Result Cache


Oracle Database 11g offered plenty of performance management features; one of those was server side result caching. Result caching implements a caching mechanism in an Oracle Database. Using this feature, you can cache the results of an SQL query or a PL/SQL function within a designated area in the SGA (System Global Area), known as Server Result Cache.

Note

The result caching feature is available in Oracle Database Enterprise Edition only.

Conventionally, when a query is executed for the first time, Oracle looks for the required data blocks in the buffer cache first. If the data blocks are already in the buffer cache (because previous SELECT queries had retrieved them), the current SQL query gets executed using that data. If not, Oracle performs physical I/Os to fetch the table data from the disk into the buffer cache and then moves ahead for the query processing. The next time the same SELECT query with the identical predicates and inputs is re-executed, in...