How to Navigate Oracle 12c’s Enterprise Manager Express
Oracle 12c’s Enterprise Manager (EM) Express main page, or the dashboard, gives you an idea of your database’s overall health. This is the way it looks when you first log in.
All the major sections are listed and separated on the menu bar at the top according to task. The sections are
Database name: Clicking this link always takes you to the main dashboard of the database.
Configuration: This section provides information and actions against initialization parameters, memory, database feature usage, and database properties.
Storage: As you would assume, this section provides insight and tools to manage database storage.
Security: This section is for managing users, role, privileges, and profiles.
Performance: You can click this link to get an overview of the performance of the database. You see details such as I/O, CPU usage, top sessions, locks, and so on. It contains anything that might help when diagnosing performance problems on the system and tuning SQL in the database.
Dashboard in Oracle 12c’s EM Express
The dashboard is the landing page of EM Database Express when you first log in. This page gives you a general overview of what is going on in your database. It is also the gateway for the rest of the actions that can be launched within EM Database Express.
One of the nice things about Oracle 12c is that the new EM Database Express tool is much more lightweight and faster than the older Database Control because it no longer requires an Oracle Application Server running in the background to support it.
It runs directly out of the database as opposed to running in a separate Oracle Application Server container. This consumes far fewer resources. The old iAS Container was always difficult to manage and keep running at times.
The dashboard offers many panes of information:
Status: This pane gives you an overview of the main characteristics of the database, such as Version, Database Name, Oracle Home, Last Backup, and so on.
Performance: In this pane, you find a simplified breakdown of resource consumption between IO and CPU as well as time spent waiting. The dashboard just gives you a quick glance.
Incidents: If any problems have been detected and stored in the Automatic Diagnostic Repository, you see them here.
Resources: This pane gives you an overview of the database/server resource consumption for things like CPU, memory, or storage.
Running Jobs: Aptly named, this portlet gives you information about currently executing jobs in the database. These are named jobs, not run of the mill SQL execution. Named jobs, which run from the Oracle scheduler, can include statistics collection, backups, or application batch processes.
SQL Monitor: This pane shows the most recent SQL statement executions. The statement IDs are active links that you can click to access the SQL Monitor tool. On the SQL Monitor pane, you can watch the real-time execution of SQL or analyze past SQL executions.
The Performance and SQL Monitor panes aren’t available unless you have licensed the Diagnostic and Tuning packs, respectively.
Security page in Oracle 12c’s EM Express
The Security page allows you to create, drop, and alter users. It also allows you to create and drop roles. Not only can you manage users and roles, but you can also control the security and permissions of these users.
The Security page also allows you to manage profiles. Profiles are attributes that manage resource consumption and password protection in the database. For example, profile settings determine how many times a password can be reused and how long a password takes to expire.
You can create different types of profiles in your database for different classes of users. You might have one profile for web-based application users and another for batch job users. Profiles allow you to control how resources are consumed and passwords are managed by grouping users together.
Performance page in Oracle 12c’s EM Express
The Performance page is made up of two sections:
Performance hub (part of the Diagnostic pack)
SQL Tuning Advisor (part of the Tuning pack)
The performance hub is just want it sounds like: a central hub to give you a 360 degree view of what resource consumption is like on your system. Not only does it display information about database resource consumption, but it also contains some information about the operating system resource usage.
The performance of the overall operating system is every bit as important as that of the database because on many systems you will have more than one database. If the operating system itself has nothing more to give, trying to tune at the database level may just be an exercise in futility.
SQL Tuning Advisor
The SQL Tuning Advisor gives you real-time access to both running and past SQL statements. It’s a graphical interface that paints pictures of the different activities within the execution of a SQL statement. Like the performance hub, this is a separately licensed tool.
What it can do is help speed up the problem diagnosis. It isn’t required to be a strong DBA. Again, however, sometimes speed is worth paying for. The SQL Advisor lets you see execution plans at the click of a button. Again, speed is the name of the game here. If you’re fortunate enough to have your company purchase the licensing for this tool, it can certainly pay for itself.