Other than that a DataSet is a 'container'. When you pass a dataset you're not passing it with all the tables, relations... in it, you're passing just a reference. IOW in memory it still occupies the same place. Hey, Cetin,
Just a clarification - if a dataset (or XML string representation) is passed across a physical boundary (e.g. result set coming down from a web service to a client piece), then it's physically being passed.
I generally place tables into DS based on a logical grouping/assocation.
Kevin