2.5. Summary
Oracle provides a comprehensive framework for you to monitor and manage your Oracle infrastructure. The Oracle Enterprise Management Framework provides a comprehensive set of integrated tools that allow you to perform your traditional tasks more easily and efficiently as well as effectively monitor the various components in the enterprise. This framework, which you can customize, allows for centralized management of your applications using a web-based interface.
The Oracle Enterprise Management Framework is divided into these functional areas:
Managed targets
Management Services
Oracle Management Repository
Oracle Enterprise Manager 10g Grid Control
Oracle Enterprise Manager 10g Database Control
Application Server Control
Managed targets can be administered using the Enterprise Manager. Examples of managed targets include databases, application servers, web servers, applications, and Oracle agents such as the Oracle Net listener and Oracle Connection Manager Listener.
The Oracle Management Service is a Java-based web component that is the actual interface you use to monitor and control managed targets within the Management Framework.
Configuration and monitoring information collected about managed targets is stored in an Oracle Management Repository. The repository is composed of two tablespaces in an Oracle database that contain information about administrators, targets, and applications that are managed within Enterprise Manager.
The Oracle Enterprise Manager 10g Grid Control is a web-based user interface that communicates with and centrally manages all the components within the Oracle Enterprise. The Grid Control agent needs to be started when using this facility.
The Oracle Enterprise Manager 10g Database Control allows you to monitor and administer a single Oracle database instance or a single Real Application Cluster (RAC) environment. The Database Control agent needs to be started when using this facility.
The Application Server Control is a web-based component of Enterprise Manager used to monitor the Oracle Application Server 10g (9.0.4).
You can access and monitor the database using the Database Control facility. You can also interact with the database using the web-based iSQL*Plus facility. The iSQL*Plus server provides many of the same features found in the SQL*Plus command line and Windows utility but is accessed from within a web browser interface. To use the iSQL*Plus interface, you need to start the iSQL*Plus server.
You can use the Database Configuration Assistant (DBCA) to create databases. You can choose from preexisting database definitions stored as XML templates or create a database definition from scratch. All aspects of the database, including database name, file location, sizing, and initialization parameter settings, are defined within the DBCA. You can create a database after completing the database definition, or you can save the definition as a template or series of scripts to be run at a later time. You can also use the DBCA to remove databases or add options to existing databases.
You can manage and create new template definitions using the DBCA interface. This is advantageous because it serves as a way to centrally manage all your database definitions. You can also create new databases from existing databases using the DBCA. This simplifies the cloning of databases.
Oracle uses parameter initialization files to store information about initialization parameters used when an Oracle instance starts. Oracle reads the parameter file to obtain information about how the Oracle instance should be sized and configured upon startup. The parameter file can be either a plain text file, commonly referred to as a PFILE, or a binary file that is referred to as a SPFILE. You can use the Database Control facility to change existing database parameters.
The database needs to be started in order for work to be done against it. You can start up the database in one of several modes: MOUNT, NOMOUNT, and OPEN. You can also start up the database with the RESTRICT option to restrict general access to the database. You can also start up a database using the FORCE option if other startup methods fail. You can start the database using a variety of interfaces, including the Database Control utility, SQL*Plus, and iSQL*Plus.
You can shut down the database using one of several options: NORMAL, TRANSACTIONAL, IMMEDIATE, and ABORT. NORMAL, TRANSACTIONAL, and IMMEDIATE are considered clean shutdowns because no recovery is necessary upon a subsequent startup. You can shut down the database using a variety of interfaces, including the Database Control utility, SQL*Plus, and iSQL*Plus.
The alert log contains information about certain activities and errors that occur within your database. The Alert log contains a chronological summary of these events. The alert log contains a wealth of information that you can use to diagnose system problems and review histories of activities that occurred on the system.