Data caching

Server caching

Server caching stores result sets from dashboard queries to data servers for reuse. The cached result sets are reused when the server receives a request that generates exactly the same or a compatible result, for example, a statement that is identical to the previous statement, except that it has one more filter. The server and server cache are secured within the Cognos® Analytics software security infrastructure, and therefore the cached results are also secured.

Server caching works with the data cache that is specified by the modeler in a Framework Manager package or in a data module. To set up caching in a data module, see Setting up data caching.

Server caching is enabled by default, but to explicitly enable server caching, set Server data cache to Automatic from the dashboard Properties tab. For more information, see Enabling data caching.

Local caching

Local caching uses the browser to store data on the client. When local caching is enabled, the client application stores query results in the local browser. When the same query is requested again, the client retrieves the results locally instead of sending the request to the server. This eliminates network traffic and server processing time. This data is cached and reused every time when you edit the dashboard, and your edits do not require more data to be retrieved from a data server. Because local caching uses the browser to store data, if you clear your browser cache, you need to reload your local caches.

This setting automatically disables the data cache option that was set by the modeler in the package or data module.

To enable local caching, set Server data cache to On from the dashboard Properties tab. For more information, see Enabling data caching.

You can also configure the specific data elements to be cached locally. For more information, see Specifying data elements for local caching.

Dynamic Query Mode

Dynamic Query Mode (DQM) can improve query execution by reusing previously computed results. This can affect dashboards that use data sources with a configured cache. While you cannot configure DQM from the dashboard, you can change the DQM cache size from the Administration console.

Increasing the cache size allows the DQM to handle more concurrent queries, but increases resource usage. For more information, see Changing the cache size of dynamic queries.