Lesson 1

So far in this course, your interaction with Oracle has been through Server Manager and SQL*Plus. These utilities have been around for years, but since they are command driven, many people find them difficult to use.
It should come as no surprise that Oracle now provides a set of GUI-based tools for database administration. These tools are highly integrated, and are known collectively as Oracle Enterprise Manager.
Many people abbreviate that to OEM.
Enterprise Manager can be installed and configured as either a two-tier or three-tier application. The two-tier installation is the simplest. You install the software on your PC, and run the individual modules as required. The three-tier configuration is available with Oracle, and represents a great leap forward in functionality. It requires a separate Enterprise Management Server, but provides additional features such as remote job scheduling and a web-based interface. It also allows for multiple administrators to configure the DBMS.
The Oracle Database Administration Certification Test will test your ability to perform tasks with commands, not with a GUI interface. However, knowing how to navigate through the GUI utilities will probably be very useful to you in your job, and so it is a good idea to learn these.
This module will explain the basics of the Oracle Enterprise Manager architecture. After that, you will be introduced to each of the five applications that make up the DBA Management Pack. The DBA Management Pack is what Oracle calls the bundle of OEM applications used for basic database administration tasks.

Enterprise Manager Cloud Control monitoring functionality permits unattended monitoring of your IT environment. Enterprise Manager comes with a comprehensive set of performance and health metrics that allows monitoring of key components in your environment, such as applications, application servers, databases, as well as the back-end components on which they rely (such as hosts, operating systems, storage). The Management Agent on each monitored host monitors the status, health, and performance of all managed components (targets) on that host. If a target goes down, or if a performance metric crosses a warning or critical threshold, an event is triggered and sent to Enterprise Manager. Administrators or any interested party can be notified of the triggered event through the Enterprise Manager notification system. Adding targets to monitor is simple. Enterprise Manager provides you with the option of either adding targets manually or automatically discovering all targets on a host.
Enterprise Manager can also automatically and intelligently apply monitoring settings for newly added targets. While Enterprise Manager provides a comprehensive set of metrics used for monitoring, you can also use metric extensions to monitor conditions that are specific to your environment. As your data center grows, it will become more challenging to manage individual targets separately, thus you can use Enterprise Manager's group management functionality to organize large sets of targets into groups, allowing you to monitor and manage many targets as one.