A customer has several values that need to be used in the body of an email send:
* The data would be stored in a reference data extension, related on SubscriberKey.
* There may be one or more records for each subscriber.
* The audience is generally over 1 million subscribers.
* The content is time sensitive and should be sent as quickly as possible.
* The customer is not using "catch and release" sending.
* The reference data extension contains 25 columns.
Which method should be used?