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HFEJB versus "J2EE Design Patterns" on Data Access Patterns

johnny bolger
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I've just started my research in J2EE on the Business
Objects side of things. So far I've only read Head First EJB and am
currently reading "J2EE Design Patterns" (both O'Reilly)
However, I've come across some conflicting advice with regard to data
access patterns and would like some peoples opinions.
In the Head First EJB Book which is based on EJB2.0. They state that
in EJB1.1 and even in the pre-released version of EJB2.0 CMP was
inefficient clunky etc.
However they clearly say that due to fact that CMP2.0 is "light years
ahead" that "there is little reason to ever use BMP".
Now in the J2EE Design patterns Book they heavily cover Data Access
Patterns and pretty much indicate that for various reasons you would
use BMP. I didn't get the feel that they were saying that .... if
things get out of hand use these patterns but more like things will
get out of hand if you use CMP.
So I check the dates to see if the patterns book was written after EJB2.0 and it was (from my understanding). So what do people here think ?
I can see the issues about reducing the number of Entity beans.
However I thought that if I kept to a limited set of EBs either the continer would merge multiple field request into one or database
caching would solve a lot of the performance issues.
If you were going to write a sizeable enterprise application and you
are familiar EJB2.0 would you use these patterns or CMP2.0 ?
It should also be mentioned that it's a big pity that HFEJB didn't include the chapter "Performance and Patterns" which is referenced in the book. eg you will see phrases like ... We will cover that later in the P & P chapter. Maybe there's a hidden key I need to find or maybe it was left on the editing floor but there is a soft copy on the web Hmmmmm ?
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