Hi
If I retrieve an object Parent with a lazy-loaded collection Children, then when I try to access the Children collection, I should only get one more SQL statement executed?
Is n+1 selects only an issue when I had retrieved several Parents, and then tried to get each of their Children collections?
If lazy loading always resulted in n+1 selects, then I think one would be better off using detached objects pre-loaded rather than Open session in view, as the Hibernate book says 'You always want to avoid n+1 selects'. However, if there are circumstances in which it doesn't then perhaps I should use Open session in view and lazy loading.
thanks, Baljeet.

Hi,

Another approach is to specify a batch-size as mentioned here: http://docs.jboss.org/hibernate/stable/core/reference/en/html/performance.html#performance-fetching-batch

It should result in Hibernate retrieving the Children entities from the database in batches of the size that you specify.

--
Stephen Souness



blog: http://elegant-solutions.blogspot.com/

Thanks for that, I had come across the descriptions of different fetch strategies. I was thinking about Open Session In View, which in theory should allow you to define everything as lazy-loaded, but which in practice, you may need to think about whether or not you'd be accessing collections for n entities (rather than 1), or whether your single entity's collections had collections also, which would also result in n+1 selects, I believe. Then you would need to use a query instead of lazy-loading even with Open Session In View ...