Report Management - Professional SQL Server 2005 Reporting Services - page 436

Snapshot-Triggered Subscriptions
Subscriptions can be triggered when a snapshot gets updated rather than being directly tied to a schedule.
If the snapshot is refreshed on a schedule, this effectively will cause the subscription to deliver a report on
the schedule for the snapshot. Since snapshots can also be updated manually, using this technique can
guarantee that users receive updated reports regardless of the method used to refresh the snapshot. For
example, at the end of each month, after you bulk-load new data into your decision-support database,
you update the related snapshots. Triggering subscriptions on the snapshot updates brings the process
into balance without concern for the coordination of scheduled events.
The option to create a snapshot-triggered subscription is available only when the report execution is based
on a subscription. After setting up a snapshot for your report, add a subscription. Under the Subscription
Processing Options, select the radio button to run the subscription when the report content is refreshed.
Schedule-Triggered Subscriptions
The most common type of subscriptions are based on a shared or individual schedule. Schedule options
vary, depending on how frequently you want the schedule to trigger a report run. Figure 10-22 shows an
example of a daily schedule.
Figure 10-22