22.6 About Limiting Resources
Use Resource Manager to limit the types of system resources available to each user request.
Database Resource Manager, an Oracle Database Enterprise Edition option, is
exceedingly useful for maintaining an Oracle APEX instance. Using Resource Manager you can limit the types of system resources
(CPU_PER_CALL
and LOGICAL_READS_PER_CALL
)
available to each user request. By setting up multiple resource profiles, with automatic
switches between the profiles, as a user request exceeds a certain threshold you can
reduce the CPU available to that transaction. For example you may define a default
profile APEX_HIGH which can utilize 70% of CPU for 10 seconds, APEX_MEDIUM with 8% CPU
for 120 seconds, APEX_LOW with 2% CPU for 1800 seconds, and OTHERS with 20% CPU. When a
specific transaction exceeds 10 seconds, it is switched to the APEX_MEDIUM profile which
drastically reduces the CPU available. If the transaction switches to APEX_LOW and
exceeds 1800 seconds then you can cancel the SQL or terminate the session. This approach
ensures that one specific user or poorly written application cannot monopolize the CPU
causing other users and applications to respond poorly.
Tip:
Instance administrators can define Resource Manager profiles for individual workspaces.
See Also:
- Isolating a Workspace to Prevent Browser Attacks and Configuring Instance-Level Workspace Isolation Attributes in Oracle APEX Administration Guide
- Managing Resources with Oracle Database Resource Manager in Oracle Database Administrator’s Guide
Parent topic: Managing Application Performance