Expert Oracle Exadata - Parent Directory

CHAPTER 7 RESOURCE MANAGEMENTINTERACTIVE category. I/O requests coming from the INTERACTIVE category may now be prioritized overother categories such as REPORTS, BATCH, or MAINTENANCE.IORM provides three distinct methods for I/O resource management: Interdatabase, Category, andIntradatabase. These methods may be used individually or in combination. Figure 7-7 illustrates therelationship of these three I/O resource management methods.Exadata I/OResourceManagementInsideOneDatabaseAcross DatabasesIntradatabaseResourcePlanInterdatabaseResourcePlanCategoryResourcePlanIORM PlanFigure 7-7. Three methods for I/O resource managementInterdatabase IORM (Interdatabase Resource Plan): IORM determines the priorityof an I/O request based on the name of the database initiating the request.Interdatabase IORM is useful when Exadata is hosting multiple databases and youneed to manage I/O priorities among the databases.IORM Categories (Category Resource Plan): IORM determines the priority of anI/O request among multiple databases by the category that initiated the request.Managing I/O by category is useful when you want to manage I/O priorities byworkload type. For example, you can create categories like APPS, BATCH, REPORTS,MAINTENANCE in each of your databases and then set an I/O allocation for thesecategories according to their importance to your business. If the APPS category isallocated 70%, then sessions assigned to the APPS category in all databases sharethis allocation.Intradatabase IORM (Intradatabase Resource Plan): Unlike Interdatabase andCategory IORM, Intradatabase IORM is configured at the database tier usingDBRM. DBRM has been enhanced to work in partnership with IORM to providefine-grained I/O resource management among resource groups within thedatabase. This is done by allocating I/O percentage and priority to consumergroups using the same mechanism used to allocate CPU, the MGMT_Pn attribute. Forexample, the SALES database may be allocated 50% using Interdatabase IORM. That205