Concurrency erro when deleteing or updating multiple primary key fields
Figure 6-1 Entity Bean Lifecycle If you specify a non-zero value for the initial-beans-in-free-pool element in is zero.
Populating the free pool at startup improves initial response time for the EJB, because initial requests for the bean can be satisfied without generating a new instance.
Application-level caching offers the following advantages: the best choice, however, for applications that experience high throughput.
Because one thread of control exists per cache at a time, high throughput can create a bottleneck situation as tasks compete for control of the thread.
Application-level caching—also known as "combined caching"—allows multiple entity beans that are part of the same J2EE enterprise application to share a single runtime cache.
There are no restrictions on the number of different entity beans that may reference an individual cache.
Therefore, the method always returns the same value when called on the same entity object reference.For an introduction to entity beans and how they are typically used in applications, see Entity EJBs Maintain Persistent Data and Entity Bean Features.For a description of the overall bean development process, see Implementing Enterprise Java Beans.If two entity bean instances have the same home and the same primary key, they are considered identical.A client can invoke the method on the reference to an entity bean instance's remote interface to determine the instance's identity within its home.
An attempt to obtain an entity bean instance from the free pool will always succeed, even if the pool is empty.