Specifying optimistic concurrency control scheme for EJB 2.x CMP entity beans

Concurrency control is the management of contention for data resources. A concurrency control scheme is considered optimistic when locks are acquired and released over a short period of time at the end of transaction. The objective of optimistic concurrency control is to minimize the time over which a given resource would be unavailable for use by other transactions.

The Mapping editor offers two optimistic concurrency control schemes for EJB 2.x CMP entity beans:
Note: If you choose to use a collision detection column, the use of the collision detection column will take precedence over the alternative optimistic concurrency control scheme of including attributes in a predicate for optimistic access intents. In addition, all the optimistic predicate settings will be ignored for optimistic access intent.
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