The Manual Refresh Data option is used to check the database performance on ad-hoc basis. The performance snapshot is taken once. This function provides a more flexible statistics retrieval method for troubleshooting a performance problem that is currently happening on the database. It only retrieves the statistics from the monitoring tables when you specifically do the refresh. It retrieves the statistics once and then waits until you manual refresh the data again.
To manually refresh data
You can set up the monitoring to automatically poll the monitoring tables at regular intervals.
The collection of the Open Database, Open Objects, and the Process statistics are not collected unless the checkbox in front of the statistic is checked in the left pane. The enabling of the retrieval of the statistics for these monitoring options may result in the capture of a large amount of information from the database. Therefore it is not recommended to turn it on when you are using Auto Refresh to continuously monitor the activity of Adaptive Server. But when you need to troubleshoot a current database performance problem, enabling the retrieval of these statistics can help you to quickly identify the problem. Using Manual Refresh Data to take a snapshot can provide good insight on processes running, such as Top N CPU intensive processes information. Processes that are blocked by other processes are marked with a special icon and the related blocking processes can also be displayed.