Oracle RMAN 11g Backup and Recovery (110 page)

Oracle Enterprise Manager 10
g
was designed to handle this new world order. It was built around the principles of the service-oriented architecture, and its function is far wider than that envisioned for its predecessor, Oracle9
i
Enterprise Manager. Now, OEM is capable of monitoring and administering the entire Oracle ecosystem: the host servers, the disk storage, the databases, the application servers, and the applications.

Coverage of everything that OEM can do is beyond the scope of this book (we recommend
Oracle Enterprise Manager Grid Control 10
g
Handbook
from Oracle Press). This book is about RMAN, so the coverage of OEM is limited to how it employs RMAN to provide a backup and recovery interface from its console. However, OEM is worth a high-level overview to familiarize yourself with the architecture and overall function of EM prior to any discussion of its backup and recovery functions.

One more thing to note before we jump in: OEM 10
g
takes two forms: Grid Control and Database Control.
OEM 10
g
Grid Control
is the fully functioning enterprise-wide tool for managing the Oracle ecosystem.
OEM 11
g
Database Control
is the version of OEM that can be deployed as just a database management utility.

Chapter 13: Using Oracle Enterprise Manager for Backup and Recovery
311

What’s the Difference Between Grid Control and Database Control?

Enterprise Manager Grid Control has the ability to monitor the entire Oracle ecosystem. It has a centralized repository that collects data about multiple targets that exist on multiple computers and that provides an interface that displays collective information for all discovered targets.

Enterprise Manager Database Control is a subset of Grid Control functionality. It does not monitor anything but a single database and cannot be used to monitor more than one database. It runs local to the database itself.

From a database administration perspective, the functionality is mostly the same between the two utilities, with Grid Control providing more functionality for operations that involve more than one computer and more than one database. But the interface is the same, the underlying code is the same, and there is little to differentiate the two. From a backup and recovery perspective, the two utilities are nearly identical—the only primary difference being the ability to share RMAN scripts across your ecosystem and to utilize Grid Control’s knowledge of multiple servers for duplication and restore.

Grid Control

Let’s get a few things straight. First, OEM is a web application, with all the power and limitations that come with a web application. The OEM console is a web page that runs on an HTTP server that will be installed and configured as part of the Grid Control install. There is no client install.

Second, Grid Control is deployed on Oracle Application Server (OAS). When you install Grid Control, you are installing OAS, and then the Grid Control application is deployed as an Oracle Containers for J2EE (OC4J) application on top of OAS. We point this out so that you realize that a commitment to Grid Control necessitates that you familiarize yourself, to some degree, with the OAS architecture. A discussion of OAS is well beyond the scope of this book, but we will refer to it occasionally. Grid Control can monitor many different types of
targets
(as it calls them): databases, application servers, the hosts themselves, even storage devices. In this book, we stick to databases…and mostly to backups of databases only.

Grid Control performs a task that is simple to outline but complicated to realize: it gathers information about computing systems throughout the enterprise, consolidates that information into a central repository, and then displays that information to the DBA from its web console.

Based on the information, the DBA can then ask Grid Control to perform tasks on behalf of the DBA at those computing systems.

Whatever Happened to the OEM Client Install on the Oracle Client CD?

There used to be a “thick” Java client that could be installed as a stand-alone product. This was the old, Oracle9
i
Enterprise Manager client software, which could be found on the Oracle Client CD. This lingered in the 10
g
space because certain functionality had not yet been migrated from the desktop application to the Database Control web application. In 11
g,
you will find all functionality for all database options has been integrated into the web application, and there is no longer a desktop-installable OEM.