For an externally loaded table, the only property that is executed is the Post Load procedure.
Any After transformations recorded against any of the columns in an Externally loaded table will also be processed.
Post load procedures can either be manually generated from a RED provided procedure outline or generated leveraging a RED template—refer to Rebuilding Update Procedures for details.
For custom database targets, the option to use Post Load Scripts is provided, as an alternative to post load procedure. Post load scripts can be generated using a RED template—refer to Rebuilding Update Procedures for details.