@steve: I just learned that ANSI SQL supports a notion of grouping joins with parenthesis[1] which has the same effect as inheriting the join type. I'm not sure if that could actually improve performance but EclipseLink renders joins like that. Maybe rendering the join that way might be desireable for 6.0?

[1] http://dba.stackexchange.com/questions/52432/syntax-of-inner-join-nested-inside-outer-join-vs-query-results