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From Tedman Leung <ted...@sfu.ca>
Subject Re: update always called on commits (still)
Date Wed, 07 May 2008 18:35:55 GMT
Well according to the documentation "unenhanced" will become enhanced at 
runtime via "Deploy-time enhancement", "Java 6 class retransformation", 
"Java 5 class redefinition".

I think what I was getting from Michael's posting is that the automatic 
enhancement #3 has issues so right now I'm trying to weigh option #1 and 
option #2.

I originally thought option #2 would be simple but unfortunately it's not 
as it requires all the jars to be in the initial classpath which means I'm 
now messing with tomcat's original classpath and maintaining a classpath 
outside of the automatically generated WEB-INF/lib/* ...



> Just to clarify, I believe there are three possible enhancement scenarios:
> 
> 1. build-time enhancement - running 
> org.apache.openjpa.enhance.PCEnhancer over your bytecode before you run 
> your app.
> 
> 2. runtime enhancement - giving the "-javaagent=openjpa.jar" argument to 
> the JVM when you run your app.
> 
> 3. unenhanced - neither 1 nor 2.
> 
> Have you observed this problem in all three scenarios? Just (2) or (3)?
> 
> Tedman Leung wrote:
> >well, yes I'm running int "unenhanced" or in "runtime enhancement", 
> >however, I thought at was a valid way of running the system. I didn't find 
> >any documentation saying not to use that mode and it was much more 
> >"convenient" so I chose that route.
> >
> >
> >
> >On Wed, May 07, 2008 at 07:30:49PM +0200, Michael Vorburger wrote:
> >>I'm sure it's not that simple, but you aren't maybe by chance not using
> >>enhancement (build or that -javaagent) and relying on the OpenJPA
> >>feature that allows to run even unenhanced in some kind of degraded mode
> >>(there is a log at the beginning if you're in that mode), and we noticed
> >>that "change tracking" seems very unreliable in that mode, and you
> >>easily get unncessarry SQL UPDATE statements.  Note also the
> >>https://issues.apache.org/jira/browse/OPENJPA-507.
> >>
> >>If you're sure you're enhancing (correctly; not e.g. having Eclipse
> >>overwrite your .class), this is surely something else; sorry.
> >>
> >>
> >>-----Original Message-----
> >>From: Tedman Leung [mailto:tedman@sfu.ca] 
> >>Sent: mercredi, 7. mai 2008 19:12
> >>To: users@openjpa.apache.org
> >>Subject: update always called on commits (still)
> >>
> >>Hi  while back we had a discussion on updates (or more specifically
> >>preupdates) always being called even when no changes where made.
> >>
> >>I noticed there was an issue OPENJPA-506 openned for this and currently
> >>closed - but this still occurs.
> >>
> >>Both anotated @PreUpdate methods as well as updates are always called
> >>even on read only operations.
> >>
> >>Does anyone know if this is considered an open issue or a fixed issue?
> >>
> >>I'm running OpenJPA 1.1 checkout from SVN on April 28th, 2008 which is
> >>long after the fixed date of Feb 1 2008.
> >>
> >>This is now causing me even worst problems due to a recent change in my
> >>application where I switched from using @PreUpdate to @Version to keep
> >>track of the last updated time of an object. Previously the lastUpdated
> >>field was useless because it was just the last time some one read the
> >>object, now it's throwing OptimisticLockException because requests are
> >>thinking some one else updated the object (when in reality it was just
> >>readonly).
> >>
> >>-- 
> >>                                                           Ted Leung
> >>                                                           tedman@sfu.ca
> >>
> >>You know you're in trouble when snow starts to clog your ram jets.
> >>
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-- 
                                                           Ted Leung
                                                           tedman@sfu.ca

You know you're in trouble when snow starts to clog your ram jets.

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