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From Michael Simons <michael.sim...@optitool.de>
Subject Re: Problem with join fetch
Date Mon, 25 May 2009 12:01:07 GMT
Hello Catalina,

> If you define ToMany fetch type to EAGER, then a simple
>    select a from A
> will get all Bs and Cs loaded.

unfortunately, using EAGER does not solve the (N+1)-problem. If there are L instances of A
each
holds M instances of B and each b has N instances of C then there will be L*M*N queries
generated to get the instances of C.
In the case that we need to solve here, there are about L=100, M=15, N=2 and there's even
one
more level D with about 2 instances per each c. So there are about 6000 queries, to get
information that can be fetched in one single select.

Michael



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