i would like to import a csv file with a list of customers into a workflow and intersect the imported data with the result of a query (matching can take place with one column like customer ID). How can this be done most efficiently? The csv data should not be imported to the ACS data model first.
This would need to be done using the Enrichment activity. You can configure it to accept data from two sources, and choose which is the primary source. You then enrich that data with data from the alternative source.