Is is possible to override the hbm.xml fetch strategy. I have one to many mappings which are set to lazy = "false". Is it possible to write a query so that the association is NOT initialized (as if you had set lazy = "true") in the mapping.

My initial instinct was that it would be possible to use the Criteria API and call
setFetchMode("associationName", FetchMode.NONE), but this is not possible. Is there any alternative mechanism or do you simply need to change the mapping file?

What you're saying is exactly what you should do. The thing is I don't know where you picked the FetchMode.NONE value... Which version of Hibernate are you using ? 2 or 3 ?

You just have to specify FetchMode.SELECT which is equivalent to lazy="true" in the mapping instead of FetchMode.JOIN which is equivalent to lazy="false".

My understanding of FetchMode.SELECT is that it will issue SQL to populate the association. You won't end up with a proxy but an extra SQL select. Is this not correct?

No, as I said, FetchMode.SELECT is equivalent to lazy="true", so just test it. The collections are always proxified will Persistent(Set|List|...).

If you set this mode, an iteration on the list will retrieve each line one by one. But don't believe me, test it, you'll never remember this correctly without having seen it by yourself :-).