Re: [eclipselink-users] Notifications about external database changes

[James Sutherland <jamesssss@xxxxxxxxx>]

You can disable the shared cache using the persistence.xml property,

"eclipselink.cache.shared.default"="false"

Trigger or specific database mechanism are the only way to get events from
the database.  You could maintain a open/changed or change number column in
your tables that the external application must update, so you can at least
limit your polling query to filter on that column.



philk wrote:
> 
> Hello,
> 
> I am having a little trouble understanding how my EntityManager could be  
> informed about changes to the database that were made by a 3rd Party  
> program in another process. Is there any recommended way to reload/refresh  
> the entities in the entity manager? I am currently using  
> "eclipselink.refresh=true" as a query hint in my getResultList() calls.  
> But once you forget that, you will not see external changes. Is there a  
> way to globally turn of entity caching?
> 
> Also is there a "non-pull" way of getting notified about changes in tables  
>  from outside? My application needs to monitor progress on orders and  
> currently I am polling every 10 seconds to do a full entity update using a  
> "select e from SendOrder e" query. Which is of course highly inefficient.  
> I could use DB-triggers but they cannot be managed by JPA and are not  
> available on every database.
> 
> Any ideas?
> 
> Thanks,
> Phil
> 
> 


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