Using Agents to Seed the Oracle BI Server Cache

7-28 System Administrators Guide for Oracle Business Intelligence Enterprise Edition 4. Browse the explorer tree to display the associated cache entries in the right pane.

5. Select the cache entries to purge, and then select Edit, then Purge to remove them.

Or, right-click the selected entries and then select Purge. – In Cache mode, select the entries to purge from those displayed in the right pane. – In Physical mode, select the database, catalog, schema or tables to purge from the explorer tree in the left pane. In Cache mode, you can purge: – One or more selected cache entries that are associated with the open repository. – One or more selected cache entries that are associated with a specified business model. – One or more selected cache entries that are associated with a specified user within a business model. In Physical mode, you can purge: – All cache entries for all tables that are associated with one or more selected databases. – All cache entries for all tables that are associated with one or more selected catalogs. – All cache entries for all tables that are associated with one or more selected schemas. – All cache entries that are associated with one or more selected tables. Purging deletes the selected cache entries and associated metadata. Select Action, then Refresh or press F5 to refresh the cache display.

7.8 Cache Event Processing with an Event Polling Table

You can use an Oracle BI Server event polling table event table as a way to notify the Oracle BI Server that one or more physical tables have been updated. Each row that is added to an event table describes a single update event, such as an update occurring to the Product table in the Production database. The Oracle BI Server cache system reads rows from, or polls, the event table, extracts the physical table information from the rows, and purges stale cache entries that reference those physical tables. The event table is a physical table that resides on a database accessible to the Oracle BI Server. Regardless of whether it resides in its own database, or in a database with other tables, it requires a fixed schema described in Table 7–6 . It is normally exposed only in the Physical layer of the Administration Tool, where it is identified in the Physical Table dialog as an Oracle BI Server event table. Using event tables is one of the most accurate ways of invalidating stale cache entries, and it is probably the most reliable method. It does, however, require the event table to be populated each time that a database table is updated. Also, because there is a polling interval in which the cache is not completely up to date, there is always the potential for stale data in the cache. See Section 7.8.3, Populating the Oracle BI Server Event Polling Table for more information. A typical method of updating the event table is to include SQL INSERT statements in the extraction and load scripts or programs that populate the databases. The INSERT statements add one row to the event table each time that a physical table is modified.