I read the discussion with great interest,

But I'm still confused.  If read-only is to be used only with commit option A,
then this statement I found on the wiki looks contradictory:

anonymous wrote : Note, that in case of commit option B, when a transaction 
first time accesses an instance (invokes CMP/CMR getter or setter or another 
business method) even if the instance is cached its data will be loaded from 
the database (re-read the spec's quote). So, the cached data is not really 
used. Except for one case, i.e. when the instance or some of its CMP fields 
marked as read-only in jbosscmp-jdbc.xml In this case, read-only fields won't 
be reloaded from the database. 
http://wiki.jboss.org/wiki/Wiki.jsp?page=CMPCaching


any comment on this ?
by the way, why did they write about jbosscmp-jdbc.xml when read-only is 
usually set in jboss.xml ?

And could you also comment on this :
anonymous wrote : you should never do fine grained access of entity beans
  | in multiple transactions. It remains a bit blurry for me.

Talking about docs and wiki, I found out that read-only was indeed to be used 
to "relax" a pessimistic lock mechanism, as the read-only bean or method is 
only locked for the duration of the invocation.

But I didn't figure out :
why read-only was not to be used with other commit option than A ?
and how read-only was degrading the performance ?
Anybody could tell me  ?

Thanks a lot !
Regards,
François.

View the original post : 
http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3919982#3919982

Reply to the post : 
http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=3919982


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