SQL Statements

In the SQL Statements area, you can find information about the executed SQL statements:

The number of SQL statements is a direct indication of database activity. The ratio of ROLLBACK actions to COMMIT actions may indicate logical inconsistencies in one or more SQL statements.

I/O Activity

In the I/O Activity area, you can see information about the I/O activities that were triggered by the database system. This includes information about the logical and physical read and write transactions. In a physical read or write activity, the system accesses a volume directly. A logical read or write activity, on the other hand, uses data stored in the data cache or another cache.

More information: I/O Operations

Lock Activity

The Lock Activity area gives you information about the maximum number of available database locks (entries) as well as the number of locks set since the start of database monitoring. If the number of locks set approaches the number of available locks, it is a good idea to raise the value of the MAXLOCKS general database parameter.

Escalations shows the total number of rows locked by a single user session. If more than a certain percentage of the rows of a table are locked by a single user session, the database system locks the entire table. The threshold for escalations follows the MAXLOCKS values for this database.

If a locked object is requested again, a lock conflict occurs. If a large number of collisions occurs in your system, this means that a specific lock is being held too long, or multiple users are trying to access the same part of the database too often. The values for lock owner and lock requester refer to the locks at the time the transaction is executed.

More information: SQL Locks

Logging Activity

The Logging Activity area shows you, among other things, the number of log pages (written log pages, such as pages filled with redo log entries). If the value of Log I/O Queue Overflow is greater than 0, increase the space available for log queues. You can configure the size of log queues with the LOG_IO_QUEUE special database parameter and the number of the log queues with the LOG_QUEUE_COUNT support database parameter.

More information: Concepts of the Database System, How Databases Log Data Changes

Scan and Sort Activity

The Scan and Sort Activity area shows you, among other things, information about table scans and data record sorting. Keep the number of table scans to a minimum, since a high number of sequential scans can have a negative effect on database performance.

More information: Bottlenecks

Resetting Monitor Data

If you want to monitor the database status at the current time, choose  Activity Monitor Reset Monitor Data . All relevant database system tables are initialized and the statistical data for Database Monitoring is collected from that time forward.