Book Image

Oracle Advanced PL/SQL Developer Professional Guide

By : Saurabh K. Gupta
Book Image

Oracle Advanced PL/SQL Developer Professional Guide

By: Saurabh K. Gupta

Overview of this book

PL/SQL (Procedural Language/Structured Query Language) is Oracle Corporation's procedural extension language for SQL and the Oracle relational database. Server-side PL/SQL is stored and compiled in the Oracle Database and runs within the Oracle executable. With this guide Oracle developers can work towards accomplishing Oracle 11g Advanced PL/SQL Professional certification, which is the second milestone for developers working at the Associate level. The Oracle Advanced PL/SQL Developer Professional Guide helps you master advanced PL/SQL concepts. Besides the clear and precise explanation on advanced topics, it also contains example code and demonstrations, which gives a sense of application and usage to readers.The book gives a deep insight that will help transform readers from mid-level programmers to professional database developers. It aims to cover the advanced features of PL/SQL for designing and optimizing PL/SQL code.This book starts with an overview of PL/SQL as the programming database language and outlines the benefits and characteristics of the language. The book then covers the advanced features that include PL/SQL code writing using collections, tuning recommendations using result caching, implementing VPD to enforce row level security, and much more. Apart from programming, the book also dives deep into the usage of the development tool SQL Developer, employing best practices in database environments and safeguarding the vulnerable areas in PL/SQL code to avoid code injection.
Table of Contents (22 chapters)
Oracle Advanced PL/SQL Developer Professional Guide
Credits
Foreword
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Using temporary LOBs


Temporary LOBs provide a temporary solution to hold a LOB data in a limited scope—maximum up to a SESSION. It can be used in a PL/SQL block as a local variable. A temporary LOB created using the DBMS_LOB package resides in temporary tablespace. Note that neither the redo logs nor the rollback information is generated for it. For this reason, they yield better performance within a block.

A temporary LOB can be created as any of the internal LOBs, but cannot be initialized using empty LOB locator constructor methods (EMPTY_CLOB and EMPTY_BLOB). They can be a handy solution when manipulative operations are performed on the LOB type column in a PL/SQL block.

Temporary LOB operations

A temporary LOB allows most of the LOB operations such as create and update. A temporary LOB, being a temporary component, must be freed-up as soon as its related actions are over. The DBMS_LOB package provides the APIs to handle temporary LOB actions.

Managing temporary LOBs

The DBMS_LOB package...