• Quick Select: Use to quickly set the time range to one of Last Hour, Last 8 Hours, Last 24 Hours, or Last Week.

• Time Range: Use to set the date and time range for Performance Hub to monitor.

• Time Zone: Select an entry from this list to specify times based on Coordinated Universal Time (UTC), your local web browser time (Browser), or the database time zone setting (Database).

• Activity Summary (Average Active Sessions): shows active sessions during the selected time range. It displays the average number of active sessions broken down by CPU, User I/O, and Wait. It also shows the Max CPU usage.

  You can hide or show the activity summary by selecting Hide Activity Summary.

• Reports: Allows you to generate and view different types of performance diagnostic reports, including:

  • Automatic Workload Repository (AWR): This report is available by default. The AWR report collects, processes, and maintains performance statistics for problem detection and self-tuning purposes. This data is both in memory and stored in the database.

  • Active Session History (ASH): This report requires that you enable Database Management. The ASH report contains data that helps you triage transient performance problems and perform scoped or targeted performance analysis by various dimensions such as time, session, module, action, or SQL identifier.

    See Enable Database Management Service to Monitor and Manage Autonomous Database for more information.

ASH Analytics is displayed by default. This tab shows Active Session History (ASH) analytics charts to explore the Active Session History data.

You can drill down into database performance across multiple dimensions such as Consumer Group, Wait Class, SQL ID, and User Name. Select an Average Active Sessions dimension and view the top activity for that dimension for the selected time period.

For more information, see ASH Analytics.

SQL statements are only monitored if they've been running for at least five seconds or if they're run in parallel. The table displays monitored SQL statement executions by dimensions including Last Active Time, CPU Time, and Database Time. The table displays currently running SQL statements and SQL statements that completed, failed, or were terminated. The columns in the table provide information for monitored SQL statements including Status, Duration, and SQL ID.

For more information, see SQL Monitoring.

ADDM tab provides access to analysis information gathered by the Automatic Database Diagnostic Monitor (ADDM) tool.

ADDM analyzes AWR (Automatic Workload Repository) snapshots on a regular basis, locates root causes of any performance problems, provides recommendations for correcting the problems, and identifies non-problem areas of the system.

AWR is a repository of historical performance data, therefore ADDM can analyze performance issues after the event, often saving time and resources in reproducing a problem.

For more information, see Automatic Database Diagnostic Monitor (ADDM).

Use the Workload tab to visually monitor the database workload to identify spikes and bottlenecks.

For more information, see Workload.

Blocking Sessions hierarchically lists sessions that are waiting or are blocked by sessions that are waiting. You can set the minimum wait time required for sessions to be displayed in the list, and you can view a variety of information about a session to determine whether to let it continue or to end it.

For more information, see Blocking Sessions.