Hour 14

for RuBoard

Quiz Answers


What must be maintained when using the pessimistic concurrency approach?

  1. Locks on data resources

  2. Database connections

  3. Events


a and b. Both locks on data resources and database connections must be maintained in pessimistic concurrency.


In general, how is optimistic concurrency implemented?

  1. Compare original values to current values in the data source

  2. Identify key changes, then commit updates

  3. Delete old values, then insert new values


a. In general, you will need to compare original values (that you read from the data source) to current values in the data source before the data can be updated. If any of the comparison fails (indicating that the row was updated by someone else), you have encountered an optimistic concurrency violation.


True or false: Pessimistic concurrency is designed for fast, scalable applications in .NET.


False: Pessimistic concurrency is not designed for fast scalable applications in .NET because of the expensive need to hold connections and locks.


What should be used when using the optimistic concurrency approach and XML?

  1. Blocks

  2. Tags

  3. DiffGrams


c. DiffGram s are an excellent XML structure to use when having to implement optimistic concurrency between varying systems. All that you need to test for optimistic concurrency violations is embedded in these block structures.

for RuBoard

Sams Teach Yourself ADO. NET in 24 Hours
Sams Teach Yourself ADO.NET in 24 Hours
ISBN: 0672323834
EAN: 2147483647
Year: 2002
Pages: 237

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net