
July 22, 2013 06:17 by
Mike
Reporting Service (SSRS) 2008 R2 allows us to execute reports in 3 modes:
- On Demand
- From Cache
- From Snapshots

On Demand
- This is normal approach that we follow, by hitting a report server URL. Each time a report is run, data is returned from the database server and rendered to the report.
- This approach ensures that our report is update and fresh.
- The downside of this approach is that, if n users open up this report on their browsers, queries on the report are executed n times.
- Thus this approach at times might slow down the server.
Cache
- One of the performance enhancements techniques is to cache a report when it is initially run.
- This means that if another user requests for the report, the same report is served to the user from the cache.
- This avoids people querying the database server from each report rendering.
- To make sure that people do not receive too much stale data, we can set a time to invalidate a cache.
- This is a good performance enhancement technique for slow running reports.
Snapshots
- Report snapshots are created at a particular schedule for certain parameters.
- Please note that parameters cannot be changes on snapshot reports.
- SSRS 2008 R2 allows to schedule the snapshot creation times.
- Users can directly render a report from a snapshot. However please note that not all reports can have snapshots, especially the ones that prompt users for credentials.