CHAPTER 10 MANAGING REPORTS- If the cached report has parameters that change during subsequent executions,
and each user receives a new report based on that parameter, each report that’s
generated becomes a cached copy specific to the parameter value. - The report’s data source isn’t set to Windows authentication or to prompt the user
for login credentials.
For our report, instruct SSRS to cache a temporary copy of the report and expire the cached copy
after ten minutes. Ten minutes is generally a good length of time to maintain cached reports, although it
really depends on the time sensitivity of your data. The data in a cached report will, of course, reflect the
time at which the report was rendered rather than the current time, and short of printing the execution
time on the report, users have no way to know if they’re viewing a cached or live report.
The second selection, Render This Report from a Report Snapshot, shouldn’t be confused with a
snapshot that creates a report history. An execution snapshot, unlike a history snapshot, is viewed from
a Report folder in Report Manager just like on-demand reports would be viewed. History snapshots, on
the other hand, are viewed from the Report History tab of the report and can accumulate many copies.
Snapshots don’t expire like cached reports; rather, they’re refreshed at a specified interval. If you
choose to generate an execution snapshot for a report, then that report can’t be cached. In this example,
don’t select this option.
The final report execution option sets the timeout interval for the report, either at a default setting,
which is typically 1,800 seconds (30 minutes), or at a specified value. This is an important setting
because long-running reports use valuable system resources. You’ll use the default value for the AR
Reconciliation report.
We mentioned the trade-off involved in using caching for reports with time-sensitive data. Another
important consideration when choosing to use either snapshots or cached reports is disk space. Over
time, history and cached reports set with lengthy expiration times can accumulate. The cost of disk
storage compared to the performance and subsequent productivity increase is negligible, however, and
shouldn’t stop anyone from taking advantage of these beneficial features of SSRS.
Managing Subscriptions
Subscription services for SSRS provides a means for delivering pre-executed reports to specified
locations, to a user via e-mail, to a network file share, or even directly to a printer. Using subscriptions
has several key benefits. Internally in an organization, employees need key information at certain times,
such as daily or at the end of a month. Externally, customers may want to receive newsletters or financial
statements on a predetermined schedule. Subscriptions can accommodate both of these needs easily.
Setting up subscriptions has the added benefit of allowing you to schedule the processing of
resource-intensive reports at off-peak hours, thus ensuring little or no degradation to network
performance during periods of heavy usage. You’ll be working with two types of subscriptions in this
section:
- Standard subscriptions: Statically set up for one or more users.
- Data-driven subscriptions: Subscriber lists can be derived from multiple data
source locations and can be generated from a custom query.
Note Data-driven subscriptions are by far the most powerful form of subscriptions. They’re available only in the
Enterprise edition of SSRS.