Programming Microsoft® ADO.NET 2.0 Core Reference, 2nd Edition

Questions That Should Be Asked More Frequently

Q	Of my three options for creating DataTable objects, which should I use? Creating them using code before populating them using a SqlDataAdapter Creating them implicitly by calling SqlDataAdapter.Fill Creating them by calling SqlDataAdapter.FillSchema
A	I strongly recommend the first option. As of this writing, creating tables using code is about 20 times faster than calling the FillSchema method of the SqlDataAdapter.
Q	I created my DataTable objects in code, as you recommended, but now the code that fills my DataTable objects runs much more slowly. Why is that?
A	I’m so glad you asked. You’ll see this slowdown if your DataTable objects have constraints. As you retrieve data from your data store and add rows ...