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CHAPTER 15

Enterprise Manager

IN THIS CHAPTER

• Installing Enterprise Manager 345
• The Enterprise Manager Console 345
• Backup Manager 353
• Data Manager 354
• Instance Manager 357
• Schema Manager 358
• Security Manager 358
• Software Manager 359
• SQL Worksheet 360
• Storage Manager 361

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Oracle Enterprise Manager (OEM) is one of the most under-utilized tools that Oracle Corporation has to offer. It allows database administrators and users to easily view and manipulate the various aspects of the Oracle database. Previously, Oracle provided two basic tools called SQL*DBA and Server Manager. These tools were used primarily for server-side administration. They were limited in features and usability. OEM is a quantum leap over these primitive tools. It allows the user to administer, monitor, and tune databases on different machines, platforms, and versions. It also allows the integration of third-party software. It is designed to be a single point of contact for almost all Oracle activities. Many of the functions of OEM are simply commands issued to command-line utilities. This means that although OEM is much easier to use, other tools (such as Server Manager or SQL*Plus) can be used if OEM is unavailable.

TIP

Do not rely on OEM in critical situations such as recovering a database. OEM has been known to lock up and wreak havoc during the most inopportune times. Instead, use the line-command tools provided with the Oracle database. It is also advisable to use the tools that reside on the server, not the client. In other words, do not use Server Manager on a workstation. Instead, log in to the server (telnet for UNIX and VMS) and use those tools.

Enterprise Manager is actually a suite of applications, which are listed in Table 15.1. Some of these applications come in a performance pack that is sold separately by Oracle. The performance pack has some very useful applications and is a worthwhile buy.

Table 15.1. Enterprise Manager applications.

Applications	Description
Enterprise Manager	Main console of Enterprise Manager
Backup Manager	Backup and recovery
Data Manager	Export, import, and load data
Instance Manager	Startup/shutdown, initialization parameters
*Lock Manager	Monitor and resolve database locks
*Oracle Expert	Database tuning
*Performance Manager	Monitor current database activity
Schema Manager	Management of all user objects
Security Manager	Management of users, roles, and profiles
Software Manager	Distribution of software in a client/server environment
SQL Worksheet	SQL line commands, similar to SQL*Plus
Storage Manager	Management of data files and tablespaces

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Applications	Description
Tablespace Manager	Advanced management of tablespaces
Top-Session Monitor	Monitor current user activity
Trace	SQL monitoring tool for development

*Included in the performance pack

Installing Enterprise Manager

Installation of OEM is one of the most difficult aspects of the tool. Pay careful attention to setting up communication daemons and intelligent agents. OEM uses these processes to perform complex tasks , such as scheduling jobs on remote databases, starting and stopping the database, and alerting the DBA of potential problems. Plan to take at least one week to set up OEM. Oracle is continuing to find ways to simplify this process. One of the recent (7.3.3) enhancements is the Discover New Services wizard. The wizard is given a server name and proceeds to discover databases, listeners, and agents that reside on that server.

OEM often depends on a set of tables called the repository. The repository can be created in any Oracle database. It stores information generated by the console and some of the other managers. Several of the other managers require access to the repository for complete usability. The repository allows the DBA to manage the databases from more than one location. A DBA could start a process on Friday afternoon and dial in from home on Saturday to check on its progress.

The Enterprise Manager Console

The console initially asks for repository login information, as shown in Figure 15.1.

During the installation of OEM, the installer asks whether the user would like to automatically create a repository. If the creation process fails, the user can follow these steps to manually create the repository:

1. Go to the DOS command prompt.
2. Enter the following command:

Vobsh _c myuser/mypassword@mdb _o CREATE _p "Enterprise Manager"

NOTE

Replace myuser/mypassword@mydb with the proper connection criteria.

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Figure 15.1.
Repository Login
Information dialog box.

After connecting to the repository, the user is shown the console. (See Figure 15.2.) The console is split into four windows :

• The Navigator window
• The Map window
• The Job Control window
• The Event Management window

Figure 15.2.
Oracle Enterprise
console.

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The Navigator Window

The Navigator window uses a tree structure to list the databases, groups, listeners, name servers, and parallel servers. Click the Databases folder to see a list of all databases that are listed in the Tnsnames.ora file. This file is located in the $ORACLE_HOME/network/admin directory. Clicking the + sign beside a database will attempt a connection. If the connection is successful, a list of nine folders is shown. (See Figure 15.3.)

Figure 15.3.
Menu after right-
clicking a data file.

These folders are the starting points for most database activity. Clicking the Datafiles folder will reveal all data files associated with database instance. Right-clicking a data file will reveal a short menu list of possible choices. (See Figure 15.3.) These choices include the following:

• Create
• Create Like
• Quick Edit
• Related Tools

These choices will differ depending on which folder or object is currently selected. Typically, this menu will allow simple tasks (such as creating a data file) to be performed directly from the console. Complex tasks can be done by clicking Related Tools. This menu will show all appropriate tools for managing that particular object (such as Storage Manager or Backup Manager for data-file objects).

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