Exadata I/O Resource Manager (IORM) and Database Resource Manager (DBRM)

I/O Resource Manager (IORM) provides a way to manage I/O resource bandwidth for multiple databases in an exadata environment.  It helps you to priority I/O of a production database over test databases, divide I/O resources among different classes of queries (DSS, reporting) or non-critical jobs ETL, etc.

With the traditional solution, DBAs put critical databases on dedicated storage , add more disks, or reschedule non-critical tasks at off-peak/after business hours, which are expensive and tedious solutions. To solve this issue, Exadata's IORM manges I/Os based on your prioritization and resource usage regulation based on user's priority, consumer groups and resource plan.

1)  Create Consumer Groups for each type of similar workload and create rules to dynamically map sessions to consumer groups based on session attributes

2)  Create Resource Plans:  3 plans 

     Ratio-Based Plan:  OLTP 60%, DSS 30%, Maintenance 10%

     Priority-Based Plan:  Priority 1:  OLTP, Priority 2:  DSS, Priority 3 :  Maintenance

     Hybrid Plan:  Level 1        Level 2

     OLTP             80 %         

     DSS               10                90%

     Maintenance   5%

Configuring Consumer groups and Plans using dbms_resource_manager package, resource manager enterprise manager.

You can create multiple plans ( day plan, night plan, maintenance plan), but only one plan can be enabled at a time.  To set plan you can set the resource_manager_plan parameter or use the job scheduler to enable the plan.

IORM allow multiple databases to share exadata storage effectively by not allow the test databases to impact production database and share the resource among production databases effectively.  

Inter-database plan:  allocates resources for each database and the plans can be configure/enable via cellcli.  Exadata use Inter-database plans and intra-database(based on consumer groups from that database) to prioritize the production databases over Standby, QA and test databases.

Database	Level 1	Level 2	Level 3
Production OLTP	70%
Production Reporting	30
DR OLTP Standby		100
QA database			70
Development database			30

Category Plan:  Category is an attribute of each consumer group.  The plan allocates resources for each category to manage multiple workload types

by using category plan, inter-database plan and intra-database plan.