Burst Calculations Using External Data

A Burst calculation can involve External Data in more than one way. The burst driver can pull supplementary information from an external connection — for example, email addresses used to distribute a sub-report — and burst targets can themselves query external data sources. When they do, there are two things to be aware of: how per-user authentication is timed, and whether the burst can be scheduled through Automator.

Authentication Timing

Burst calculations use the same Authentication timing setting as Table Lookup calculations. For what the two options mean, when the user is prompted, and guidance on choosing between them, see Controlling When Authentication Prompts Occur.

For a burst, the setting is configured on the burst calculation in the driver, and it governs the burst target's per-user connections:

• On report open — the target's per-user connections are authenticated when the driver is opened.
• When first used — the target's per-user connections are authenticated when the driver first uses the target.

Note

Remember that table lookups within the burst target's variables are always considered to be 'On report open' regardless of the table lookup's 'Authentication timing' setting.

Client Connections and Automator

External Data connections can be either server-side or client connections. A client connection is private to the user who created it and is not available to the DAS server.

Because of this, a burst that relies on a client connection — whether the driver uses one to pull in data or a burst target does — cannot be run through Automator. The server has no access to the user's private connection, so the scheduled run has no way to reach the data. If a burst needs to be scheduled, use a server connection instead.