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

LOB data types in Oracle


Oracle provides four data types dedicated for declaring large objects, namely: BLOB, CLOB, NCLOB, and BFILE.

BLOB and CLOB

There are three types of internal LOB data types, namely:

  • BLOB: The Binary Large Object data type is used to store large binary files that cannot be logically broken down to data bits such as PDFs, images, audios or videos, and so on.

  • CLOB: The Character Large Object data type stores the single-byte character data in the database character set format. It supports fixed-width character formats.

  • NCLOB: The CLOB data type that can store national character set data and support varying width format character sets.

Note

Starting from Oracle 10g, Oracle can cast the CLOB data to the VARCHAR2 data implicitly.

BFILE

A BFILE is an SQL data type for the external LOB data type. It is the read-only data type that stores a locator for a binary file whose physical location is outside the Oracle Database. Deleting a BFILE column value (or setting it to NULL) will drop...