Managing IBM Cognos Business Intelligence cube cache clearing

IBM® Cognos® Business Intelligence report results are automatically cached, which reduces response time for subsequent report queries from the same user or subsequent users. To obtain refreshed report results, you must clear the Cognos cube cache based on an interval setting.

Configure a longer cache-clearing interval if you want to further improve report response time by caching more queries. The first report query executed after the cache is cleared will cause the queried measure values to be recalculated.

The two methods you can use to clear the Cognos cube cache based on an interval are described in the following sections.

Using the Cognos automatic cache-clearing configuration at a specified interval:

When Cognos is installed with Business Monitor, the cache clearing interval is set to -1 by default.

You can configure the global interval for all monitor models in the cognos\configuration\xqe.securecache.config.xml file by following these steps:

Locate the section of the file titled .
Replace both occurrences of <clearCacheEveryXminutes x="1"/>, using a value of X to specify the cache-clearing interval in minutes.

A value of '-1' indicates that Cognos will never clear the cache automatically.

Using the IBM Business Monitor scheduled service for IBM Cognos BI cube cache clearing:

Business Monitor manages the cube cache-clearing frequency for a monitor model. You can change the default interval of 5 minutes.

When the Business Monitor scheduled service approach is used, the Cognos global value of clearCacheEveryXminutes should be set to -1 so that Cognos does not also try to clear the cache.

The benefits of having Business Monitor manage the cube cache-clearing frequency are that the cache-clearing cycle can be synchronized with other Business Monitor scheduled services, such as data movement service, and that the interval can be specified per monitor model.

To manage the IBM Cognos Business Intelligence cube-caching services using the WebSphere® Application Server administrative console, perform the following steps:

Click Applications > Monitor Services > Monitor Scheduled Services.
Click the monitor model.
Click Scheduled Services > Cognos Cache Clearing.

Tip: If initial report queries are taking too long even with cube caching configured, you can enable the cube summary table refresh service (available on DB2 for Linux, UNIX and Windows only). The cube summary table refresh service pre-aggregates the dimensional values in the background, which improves the dashboard response time even for the first report request after the cube cache is cleared. If the cube summary table refresh service is enabled, configure both services to run on the same interval and timing to ensure that the cached values are the most recent values.