Performance Tip: Run Prompts Upfront

Run Prompts Upfront. In most data warehouse environments, data does not change during the day. This means prompt values do not change during that period. So it is a waste of time and server resources to have those prompt queries being executed over and over again every time someone runs a report. IBM Cognos offers standard functionality to avoid this by pre-caching the prompt results when it concerns non-cascading prompts. This way, when a user triggers a report with prompts, Cognos will re-use its local cache instead of sending queries back and forth to the data source.

Cognos Execute Prompts Upfront

To enable this, you create a Job containing all the reports with prompts that qualify. Then you schedule that job after each data update. In the job properties, you will find an option “Run the report to”, set this option to “Refresh the report cache”.

Cognos Refresh the Report Cache

Cognos Refresh the Report Cache 2

For each report the report prompt queries will then be executed and cached for re-use later on. If you have time-consuming prompt pages, this can have a great impact on performance. By extension, if you have fairly straightforward reports with a limited number of prompt value combinations, you might also just schedule all the different report versions for immediate consumption.

Cognos Service