For information on how best to interpret these statistics, see Oracle Server Tuning . The Buffer Gets Rate chart displays information about the buffer gets rate of the database instance. A virtual circuit is a connection to a database instance through a dispatcher and the shared server currently processing the user's request. Only information about Oracle files is shown in this chart. The Latch chart displays latch activity statistics for processes of the database instance.
Latches are low-level locks on shared internal structures.
The Library Cache Details chart displays library cache performance statistics for the library cache. The library cache contains shared cursors and is part of the shared pool in the SGA of the database instance. Active chart displays the number of user sessions actively using the database instance at the current time. On chart displays the number of concurrent user sessions logged on to the database instance, whether or not activity is being generated. Running chart displays the number of concurrent user sessions logged on to the database instance and currently running a transaction.