Oracle Cloud Infrastructure Documentation

ADDM Data

To view the Automatic Database Diagnostic Monitor (ADDM) information:

  1. Open the Performance Hub page from the database details page, if not already open.

    Note

    For more information about how to navigate to the Performance Hub page, see:

  2. Click ADDM to open the ADDM tab.

  3. Select a time range from the Quick Select field. The page displays data for the selected time period.

  4. In the Activity Summary area, click one of the gray AWR Snapshot icons to display findings for the associated ADDM task.

    A white check mark in the gray icon indicates that there are problem findings available. When selected, the gray icon changes to blue.

    For a wider time period, for example Last Week, there may be multiple ADDM tasks. The Activity Summary area displays icons indicating groups of tasks. Click an icon to open the list where you can select a particular ADDM task.

    Note

    Alternatively, you can select a Task Name in the ADDM tab or by moving the time slider close to a snapshot icon.

    Note

    When you manually change the ADDM task selection, either by clicking the gray icon for an associated AWR Snapshot, or by selecting an option from the ADDM task menu, the time slider position and size are adjusted to cover the analysis period for the ADDM task.

  5. Hover over the icon to display a message about the AWR Snapshot and ADDM task, including the number of findings for the ADDM task.

    The findings are displayed in two tables:

    • Findings - If there are findings, then this table shows the Name of the finding, Impact, Number of Recommendations, and Average Active Sessions for that finding. If there are no findings available, then the table displays a message that says there are no ADDM analysis available for the selected time period.

    • Warnings and Information - This table is displayed next to the Findings table.

      It lists messages related to the findings.

      • Warning messages identify issues such as missing data in the AWR that may affect the completeness or accuracy of the ADDM analysis.

      • Information messages provide information that is relevant to understanding the performance of the database but does not represent a performance problem. This may include identification of nonproblem areas of the database and automatic database maintenance activity.

    Note

    Both the Findings table and the Warnings and Information table are collapsible to save space when many findings are found. Click the minus icon (-) to collapse a table. Similarly, click the plus icon (+) to expand the table again.

  6. If a finding has ADDM recommendations available, then the name of the finding is displayed as a link. Click the name of the finding to display more information about the finding, including a table of recommendations for corrective actions.

    Each recommendation includes the problem area, the suggested action to take to solve it, and the estimated benefit that will result when the action is taken.

  7. Click the expand icon at the end of a row in the recommendations table to view a rationale for the recommendation.

Run an ADDM Task

Note

This feature is supported for databases running on Base Database Service, External Databases, and Exadata Database Service on Dedicated Infrastructure, but not for Autonomous Database.

To set up and run an Automatic Database Diagnostic Monitor (ADDM) task:

  1. Open the Performance Hub page from the database details page, if not already open.

    Note

    For more information about how to navigate to the Performance Hub page, see:

  2. Click the ADDM tab.

  3. Select a time range from the Quick Select field. The page displays data for the selected time period.

  4. In the ADDM tab, click Run ADDM Task.

  5. In the Run ADDM Task dialog box, select from the following options:

    • Capture and analyze current performance - to create a current snapshot. This option is selected by default.

    • Analyze past performance - to create a historical snapshot.
To create a current snapshot

  1. Select Capture and analyze current performance.

  2. Click Run ADDM.

    The status of the task is shown in the top-right corner of the window.

See the section on how to view a completed ADDM task.

To create a historical snapshot

  1. Click Analyze past performance.

  2. Select a Start Snapshot date and time and an End Snapshot date and time from the drop-down.

  3. Click Run ADDM.

    The status of the task is shown in the upper right corner of the window.

See the section on how to view a completed ADDM task.

Note

Running multiple tasks at the same time is possible, but Oracle recommends that you run only one task at a time. This helps speed the processing of each task and presents the results sooner.

View a Completed ADDM Task

Note

The time for an ADDM task to complete depends on the current system workload, the time length of the snapshot and the amount of data it contains. Performance Hub displays a message to check later if the job is taking a while to run.

When an ADDM task completes, the snapshot it created is displayed in the Activity Summary area. The time slider changes size to match the start and end times of the analyzed snapshot range and moves over the AWR snapshot icon in the graphical display.

  1. In the Activity Summary area, click the gray AWR snapshot icon to display the AWR snapshot. Hover over the icon to view the statistics of the snapshot, including the snap ID, snapshot times, task name, task owner, and the number of findings of the associated ADDM task.

    A white check mark in the gray icon indicates that findings are available. When selected, the gray icon changes to blue.
    Note

    If you have run multiple tasks concurrently, then an AWR icon for each snapshot appears under the activity summary graph and the time slider appears over the first task that you ran. To display a different snapshot, click the AWR snapshot icon for that task. The time slider moves over the AWR snapshot icon and expands or contracts to match the snapshot time.

  2. The task name, analysis period, and type are generated and displayed in the ADDM task list under the Activity Summary area.

  3. The findings for the ADDM task are displayed in the Findings tables. To view a short description of the reason for the finding, scroll down to the Findings table. Then click the information icon at the end of the name of the finding you are interested in.

    The message box explains the reason for the finding.

  4. To view the task finding details, scroll down to the Findings table and click the name of the finding. It opens the ADDM Performance Finding Details page.

    The page shows the name of the finding, the impact of the finding, the analysis period, the type of recommendation, the recommended action for the finding, and the impact of each recommendation.