Patterns of Enterprise Application Architecture

Chapter 16. Offline Concurrency Patterns

Optimistic Offline Lock

by David Rice

Prevents conflicts between concurrent business transactions by detecting a conflict and rolling back the transaction.

 

Often a business transaction executes across a series of system transactions. Once outside the confines of a single system transaction, we can’t depend on our database manager alone to ensure that the business transaction will leave the record data in a consistent state. Data integrity is at risk once two sessions begin to work on the same records and lost updates are quite possible. Also, with one session editing data that another is reading an inconsistent ...