Database Reference
In-Depth Information
Table 9-3.
Inaccessible Monitoring Issues That Can Be Solved with Real-Time ADDM
Memory Issues
Resource Issues
Issues Causing Hanging
Miscellaneous Issues
Library cache
I/O waits
Unscheduled instance
shutdown
Deadlocks
Memory allocation
Memory paging
Blocking issues
Interconnect issues
PGA extending
CPU waits
ASM issues
Sessions/processes
As Real-Time ADDM makes only a lightweight connection, also referred to as a
direct connection to the SGA
without requiring any additional locking or resources by bypassing the SQL layer and connecting through the agent,
it is able to complete connections that would otherwise be impossible with traditional connection types.
Real-Time ADDM can analyze data returned numerous ways to the database, including the SQL layer and JDBC
connection.
When performance changes in the matter of a day or an hour, Real-Time ADDM can be used to analyze what
changes were made, and to verify new batch jobs, workloads, or configuration changes.
Real-Time ADDM is available from the Performance drop-down menu from any EM12c database target.
Figure
9-48
shows the login dialog box for the ADDM console.
Figure 9-48.
Logging in to the Real-Time ADDM console requires SYSDBA credentials
The analysis can be performed on a single instance, RAC environment, or even an engineered system,
such as Exadata.
The Top Activity view, shown in Figure 9-49, displays about 1 hour of data, along with approximately 10 minutes
of previous ASH data, so you can inspect for issues that are the cause of a database hang.
