Basics of the Configuration and Storage Pages in Oracle 12c’s Enterprise Manager
The Configuration page within Oracle 12c databases allows you to monitor and make some adjustments to initialization parameters and memory components. It also lets you view the database feature usage and database properties.
Click the Configuration drop-down menu to access the following options:
Database Feature Usage
Current Database Properties
Initialization Parameters in Oracle 12c
The Initialization Parameters page lets you make adjustments to the hundreds of initialization parameters. To make a change, you simply highlight the parameter and click the Set button at the top of the page. This action opens the Set Initialization Parameter dialog box.
Note the exclamation point bubble next to the Scope line. If clicked, this bubble warns you that changing this parameter requires a bounce of the database. You can also tell by looking at the main initialization parameter page.
There is a column labeled Dynamic. If this column has a check mark, you can change the parameter on the fly. If it does not have a check mark, you have to restart the database if you want to change the parameter.
There are hundreds of parameters. On the Initialization Parameter page, you can easily search and filter the list. On the upper right, you see check boxes for the following:
Modified displays only parameters that are changed from default.
Basic displays only a subset of the database parameters that Oracle deems as basic.
You can also enter parameter names, or even partial names, in the search box to actively reduce and refine the list.
Memory in Oracle 12c
By choosing Memory from the Configuration drop-down menu, you’re taken to the Memory Management page. This page breaks down all the memory components and provides not only an overview of the current settings but also some tuning advice. You can click the Configure Memory button at the upper left to make changes.
You may not be able to make all the changes that you want without restarting the database. Notice that when you click the Configure Memory button, all that happens is that EM Database Express takes you back to the Initialization Parameter page with a filtered list of memory related parameters!
Database Feature Usage in Oracle 12c
The Database Feature Usage pane gives you an overview of all the features that are available in the database and whether Oracle has detected a use of them. This information can be important to you as a DBA for a few reasons:
By seeing what has run, you can know whether you or your colleagues are using any unlicensed features.
You can detect whether you’re using all the features you’re paying for. Maybe the next time you renew your license, any unused features can be dropped.
Knowing dates and times certain features were used can be useful when auditing activities in the database.
Current database properties in Oracle 12c
The Current Database Properties pane gives you a quick overview of the options that were chosen (or left at Default) during database creation. Having a quick list of these can be handy to help answer questions about your environment.
For example, if you ever have to open a support ticket with Oracle, this information will be relevant for them. Or, if you are installing a third-party software package into your database, the vendor might have certain properties that must be set, or other requirements. You can quickly look through this section to see how the database has been configured.
Storage page in Oracle 12c
The Storage page lets you manage objects like tablespaces and data files which are the backbone of the database storage. The page’s Storage drop-down menu has the following options:
Tablespaces: To manage your segments, you have to manage your storage containers, called tablespaces. Management includes such tasks as growing by extending or adding data files. It also includes shrinking. You can also perform other actions, such as taking tablespaces offline (for recovery) or making them read only.
Undo Management: When working with transactions and flashback technology in the database, undo management can be an important task. The undo space is important to make sure you can roll back transactions and use in the flashback features.
Although this section in EM Database Express is more of an overview than a way of making changes, it allows you to quickly see what kind of space you’re using for undo and how far back your undo lets you go. It also incorporates the Undo Advisor for keeping on top of storage when you’re leveraging the flashback retention.
Redo Log Groups: Managing redo logs is done in this section. You can create or drop groups, add members, see details about the log sequences, and archive the status of the redo logs.
Archive Logs: This section lets you see the archive logs that have been created along with their size and location. You can’t make any changes in this section. Almost all archive log changes are done with initialization parameters.
Click the Configuration Button and choose the Initialization Parameters option. Then, type archive in the search box on the right to bring up the editable archive log parameters.
Control Files: This section lets you view the control file properties. You also find a Backup to Trace button for backing up the control file to a trace file.
Backing up the control file to a trace file creates the backup in the diagnostic destination. You can view this location by looking at the DIAGNOSTIC_DEST parameter. The name of the file is also displayed after the backup completes.