Transactions and Concurrency

Abstract

I’ve spent a lot of time so far covering the hands-on work that you need to do to bring data access into your application, courtesy of ADO.NET. As many of you will know, though, there’s a lot more to building an application that uses data access than simply hitting a database and fiddling with its data. Most of you will spend your development time working on multiuser systems for your employer, systems that have to cope with more than one user simultaneously accessing and updating data from a single data source. Some of you may be heading for the lofty heights of Web development, where the issues of multiuser development take on a whole new meaning: A popular Web application could have hundreds, even thousands, of simultaneous users, all of whom could theoretically choose to update the exact same piece of information at the exact same point in time.

“No good model ever accounted for all the facts, since some data was bound to be misleading if not plain wrong.”

—James Dewey Watson, from Francis Crick’s What Mad Pursuit