Displaying Global Cache Information in the Cache Manager

Managing Performance Tuning and Query Caching 7-29 After this process is in place and the event table is configured in the Oracle Business Intelligence repository, cache invalidation occurs automatically. As long as the scripts that update the event table are accurately recording changes to the tables, stale cache entries are purged automatically at the specified polling intervals. This section contains the following topics: ■ Section 7.8.1, Setting Up Event Polling Tables on the Physical Databases ■ Section 7.8.2, Making the Event Polling Table Active ■ Section 7.8.3, Populating the Oracle BI Server Event Polling Table ■ Section 7.8.4, Troubleshooting Problems with Event Polling Tables

7.8.1 Setting Up Event Polling Tables on the Physical Databases

This section describes how to configure the Oracle BI Server event polling tables on physical databases.

7.8.1.1 Polling Table Structure

You can configure a physical event polling table on each physical database to monitor changes in the database. You can also configure the event table in its own database. The event table should be updated every time a table in the database changes. If the event polling table is on an Oracle Database, you should configure the event table in its own database object in the Physical layer of the Administration Tool. Then, ensure that the feature PERF_PREFER_IN_LISTS is not selected in the Features tab of the Database dialog for the event polling table. Following these guidelines avoids errors related to exceeding the maximum number of allowed expressions in a list. Event tables must have the structure that is shown in Table 7–6 . Some columns can contain null values, depending on where the event table resides. The names for the columns must match the column names that are shown in Table 7–6 . See Section 7.8.1.2, Sample Event Polling Table CREATE TABLE Statements for samples. Alternatively, you can use the sample event polling table in the database that you installed for use with Oracle Business Intelligence. Table 7–6 Event Polling Table Column Names Event Table Column Data Type Description CatalogName CHAR or VARCHAR The name of the catalog where the physical table that was updated resides. Populate the CatalogName column only if the event table does not reside in the same database as the physical tables that were updated. Otherwise, set it to the null value. 7-30 System Administrators Guide for Oracle Business Intelligence Enterprise Edition The Oracle BI Server must have read and write permission on the event polling table. The server reads the event table at specified intervals to look for changed data. Applications add rows to the event table when database tables are modified for DatabaseName CHAR or VARCHAR The name of the database where the physical table that was updated resides. This is the name of the database as it is defined in the Physical layer of the Administration Tool. For example, if the physical database name is 11308Production, and the database name that represents it in the Administration Tool is SQL_Production, then the polled rows in the event table must contain SQL_Production as the database name. Populate the DatabaseName column only if the event table does not reside in the same database as the physical tables that were updated. Otherwise, set it to the null value. Other CHAR or VARCHAR Reserved for future enhancements. This column must be set to a null value. SchemaName CHAR or VARCHAR The name of the schema where the physical table that was updated resides. Populate the SchemaName column only if the event table does not reside in the same database as the physical tables being updated. Otherwise, set it to a null value. TableName CHAR or VARCHAR The name of the physical table that was updated. The name must match the name that is defined for the table in the Physical layer of the Administration Tool. Values cannot be null. UpdateTime DATETIME The time when the update to the event table occurs. This must be a key unique value that increases for each row that is added to the event table. To ensure a unique and increasing value, specify the current timestamp as a default value for the column. For example, specify DEFAULT CURRENT_TIMESTAMP for Oracle Database. Values cannot be null. Note: Because this column must be a unique value that increases for each row that is added to the event table, you might need to set a very high precision if you require many inserts per second. Because of this, you might want to adjust the database feature FRACTIONAL_SECOND_PRECISION to allow fractional seconds to be used in the filters on the UpdateTime column. The Oracle BI Server truncates the timestamps to the number of digits that are defined by FRACTIONAL_SECOND_PRECISION. For example, for Oracle Database or Teradata, you might want to change FRACTIONAL_SECOND PRECISION from 0 to 6. UpdateType INTEGER Specify a value of 1 in the update script to indicate a standard update. Other values are reserved for future use. Values cannot be null. Table 7–6 Cont. Event Polling Table Column Names Event Table Column Data Type Description