Sams Teach Yourself ASP.NET in 21 Days, Second Edition By Chris Payne
Table of Contents
Day 12. Employing Advanced Data Techniques
How do transactions roll back data?
A database maintains what is known as a transaction log. This log keeps track of all the statements that are executed and the data that has changed. The database refers to this log to determine the state of the data before the statements were executed, and moves back to that state if necessary. If necessary, a transaction log can even be used to regenerate an entire database.
How much of a performance benefit do stored procedures actually provide?
That's difficult to say. It depends on the database application you're using and the commands being executed, among other things. Studies have shown, however, that using stored procedures can result in up to a 25% decrease in processing time. For more information, check out the article at http://www.4guysfromrolla.com/webtech/sqlguru/q120899-2.shtml.