• Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Ron McLeod
  • Paul Clapham
  • Bear Bibeault
  • Junilu Lacar
Sheriffs:
  • Jeanne Boyarsky
  • Tim Cooke
  • Henry Wong
Saloon Keepers:
  • Tim Moores
  • Stephan van Hulst
  • Tim Holloway
  • salvin francis
  • Frits Walraven
Bartenders:
  • Scott Selikoff
  • Piet Souris
  • Carey Brown

WAS n+1 read-ahead strategies

 
Greenhorn
Posts: 14
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi,
we are looking to migrate our application to Websphere 5, and I have a quick question that I havent been able to find the answer to on the internet.
Does Websphere 5 provide any 'read-ahead' strategies which gets around the 'n+1' problem? If so, could you point me to some link which describes it and the version of Websphere it is in, ie WAS, WAS-ND, etc?

thanks,
Rowan
 
author
Posts: 3892
5
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Now by the "N+1" problem do you mean how in a BMP bean that you have N+1 SQL calls? (1 SQL Call for the finder and N for each of the N ejbloads). If so, then this doesn't happen in CMP's at all, so use CMP's instead.
Now, if you mean is there a true "readahead" facility by which you can prefetch related EJB's when you retrieve a "root" CMP (e.g. I send a finder method to locate an "Order" CMP and all of the "OrderLineItem" CMP's are also fetched) then yes, WAS 5.0 supports this. Do a search in the InfoCenter for "Read ahead hints" and you'll find out more.
Kyle
 
If I'd had more time, I would have written a shorter letter. -T.S. Eliot such a short, tiny ad:
Thread Boost feature
https://coderanch.com/t/674455/Thread-Boost-feature
    Bookmark Topic Watch Topic
  • New Topic