What's the best way to craft an ETL with the query wizard so the preview will load for longer running queries? If we link to a query I presume we should be able to change the query so that the preview only has to return a few records and when the query is updated everything will be returned. However there seems to be some aspects of the wizard that persist after being created so I'm trying to understand when it's necessary to redo the wizard, such as changing a data source.
Also, it seems the connection objects will not nest all other objects so what's the best way to reduce the number of connections specified within a script. Ideally they should be able to reference the same connection, but many objects don't have a use parent option and have to be set explicitly.