Fetching...Lazy but initialized?

[tsar_bomba]

So, I'm using Wicket + JBoss EJB3 to build a small sample application to present to my co-workers.

I was trying to figure out an elegant way around the general tricky nature of lazily loaded collections and found this post:

http://www.jboss.org/index.html?module=bb&op=viewtopic&t=75525

Could someone explain to me what the difference between initializing the collection before returning it to the view and Eager fetching is?

Would this not be essentially the same as using Eager fetching?

Thanks!

[tsar_bomba]

So, it's been a couple of days and noone has answered me yet.

Is "pre-loading" a lazily-fetched collection not essentially the same as just using eager fetching?

Thanks!

[scraatz]

From what I understand the effect is the same, but the EJB3 engine generates different SQL-code. When you eager-load all the data is fetched in one big SQL-JOIN query. A lazily fetched relation is queried in a separate SQL query. If you always need the related entities it should be faster to eager-load.

[ejb3workshop]

There is a problem with having multiple eager many relationships within the same bean.

http://jboss.org/index.html?module=bb&op=viewtopic&t=76796

Alex
ejb3workshop.com

[tsar_bomba]

Thanks *very* much for the info, everyone - very helpful!