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

The DBMS_METADATA package


The DBMS_METADATA package was introduced in Oracle 9i. The API enables the extraction of object metadata from database dictionaries that can be optionally manipulated and re-executed on a database server. The package is owned by SYS whose public synonym is used by all users. A user with SELECT_CATALOG_ROLE can directly access the DBMS_METADATA package.

Note

DBMS_METADATA is a key enabler of metadata export functionality in Data Pump

The package pulls the object's metadata in XML form from the database dictionary and provides transform handlers to build it in the desired form. The formatted XML can then be re-executed in the database.

DBMS_METADATA data types and subprograms

As we said earlier, the DBMS_METADATA package uses the public synonyms of SYS-owned data structures. The following list shows SYS-owned object types:

  • SYS.KU$_PARSED_ITEM: An object type used to capture the attributes of an object's metadata. The object type structure is as follows:

    CREATE TYPE sys.ku...