Polling Table Structure Setting Up Event Polling Tables on the Physical Databases

7-32 System Administrators Guide for Oracle Business Intelligence Enterprise Edition Other varchar80 DEFAULT NULL ; You might need to modify these CREATE TABLE statements slightly for different versions of SQL Server and Oracle Database, or for other databases. Additionally, to specify any explicit storage clauses, add the appropriate clauses to the statements. Similarly, if you need international characters, then you must modify the DDL to handle international characters.

7.8.2 Making the Event Polling Table Active

After the table is created on the physical database, you can make it active in the Oracle BI Server. To do this, you first import the physical table, and then you mark the table object as an event polling table. To import the physical table: 1. In the Administration Tool, open the repository and import metadata from the physical database. To do this, select File, then select Import Metadata.

2. Follow the wizard steps. Be sure to select the Tables option in the Select Metadata

Types screen to import the table metadata. See Oracle Fusion Middleware Metadata Repository Builders Guide for Oracle Business Intelligence Enterprise Edition for detailed information about the Import Metadata wizard. 3. If you have multiple event polling tables, then repeat steps 1 and 2 for each event table. Be sure the data source that is specified for the event table has read and write access to the event table. The repository both reads the table and deletes rows from it, so it needs write permission. Event tables do not need to be exposed in the Business Model and Mapping layer. To mark the table object as an event polling table: 1. From the Tools menu, select Utilities. 2. Select the option Oracle BI Event Tables from the list of options. 3. Click Execute. 4. Select the table to register as an Event Table and click the button. 5. Specify the polling frequency in minutes, and click OK. The default value is 60 minutes. You should not set the polling frequency to less than 10 minutes. If you want a very short polling interval, then consider marking some or all of the tables non cacheable. When a table has been registered as an Oracle BI Server event table, the table properties change. Registration as an event table removes the option to make the table cacheable, as there is no reason to cache results from an event polling table.

7.8.3 Populating the Oracle BI Server Event Polling Table

The Oracle BI Server does not populate the event polling table. The event table is populated by inserting rows into it each time that a table is updated. This process is normally configured by the database administrator, who typically modifies the load process to insert a row into the polling table each time a table is modified. This can be done from the load script, using database triggers in databases that support triggers, from an application, or manually. If the process of populating the event table is not Managing Performance Tuning and Query Caching 7-33 done correctly, then the Oracle BI Server cache purging is affected, because the server assumes the information in the polling table is correct and up to date.

7.8.4 Troubleshooting Problems with Event Polling Tables

If you experience problems with cache polling, then you can search the Oracle BI Server activity logs for any entries regarding the servers interaction with the event table. ■ The nqserver.log file logs activity automatically about the Oracle BI Server. Log entries are self-explanatory and can be viewed in Fusion Middleware Control or in a text editor. ■ When the Oracle BI Server polls the event table, it logs queries in the nqquery.log file using the administrator account set upon installation unless the logging level for the administrator account is set to 0. You should set the logging level to 2 for the administrator account to provide the most useful level of information. You can find the nqserver.log and the nqquery.log in the following location: ORACLE_INSTANCE diagnosticslogsOracleBIServerComponentcoreapplication_obisn

7.9 Managing the Oracle BI Presentation Services Cache Settings

When users run analyses, Presentation Services can cache the results of those analyses. Presentation Services determines if subsequent analyses can use cached results. If the cache can be shared, then subsequent analyses are not stored. The files for the Presentation Services cache have names such as nQS_xxxx_x_ xxxxxx.TMP. The files are created by the ODBC driver but generally do correspond to ODBC requests that the Presentation Services cache keeps open. The files are stored in the following directory: ORACLE_INSTANCE\tmp\OracleBIPresentationServices\coreapplication_ obipsn\obis_temp The files for the cache are removed whenever Presentation Services shuts down cleanly. If Presentation Services shuts down unexpectedly, then various cache files might be left on disk. You can delete the files when Presentation Services is not running. The Presentation Services cache is different from the cache that is accessed by the Oracle BI Server. You can change the defaults for the Presentation Services cache by modifying the instanceconfig.xml file to include the cache entries. The following procedure provides information about configuration changes with which you can manage the Presentation Services cache. See Section 7.6.2.2, About Sharing the Presentation Services Query Cache for information about an ODBC procedure to use for sharing the cache. Before you begin this procedure, ensure that you are familiar with the information in Section 3.4, Using a Text Editor to Update Configuration Settings. To manually edit the settings for managing the cache: 1. Open the instanceconfig.xml file for editing, as described in Section 3.6, Where Are Configuration Files Located? 2. Locate the section in which you must add the elements that are described in Table 7–7 . 7-34 System Administrators Guide for Oracle Business Intelligence Enterprise Edition 3. Include the elements and their ancestor elements as appropriate, as shown in the following example: ServerInstance Cache Query MaxEntries100MaxEntries MaxExpireMinutes60MaxExpireMinutes MinExpireMinutes10MinExpireMinutes MinUserExpireMinutes10MinUserExpireMinutes Query Cache ServerInstance 4. Save your changes and close the file. 5. Restart Oracle Business Intelligence. Note: Avoid specifying values of less than 3 minutes for the elements that affect minutes. At such a low amount of time, refreshes can occur frequently, which can negatively affect performance and cause flickering on the screen. Table 7–7 Elements for Configuring the Cache for Presentation Services Element Description Default Value MaxEntries Specifies the maximum number of open record sets that Presentation Services keeps open at any one time. The minimum value is 3. For systems under significant loads, you can increase this value to 700 or 1000. 500 MaxExpireMinutes Specifies the maximum amount of time, in minutes, that an entry in the cache can exist before it is removed. Depending on the number of analyses being run, an entry might be removed before the time limit expires. 60 one hour MinExpireMinutes Specifies the minimum amount of time, in minutes, that an entry in the cache can exist before it is removed. The setting for CacheMinUserExpireMinutes can force an entry for a particular user to exist for a longer time than that specified by the CacheMaxExpireMinutes element. 10 MinUserExpireMinutes Specifies the minimum amount of time, in minutes, that an entry in the cache can exist after it has been viewed by a user. For example, if CacheMaxExpireMinutes is set to 60 minutes and a user views the entry during the 59th minute, the entry exists for that user for an additional 10 minutes. The user can continue paging through the data without requiring a new analysis to be run. 10