Now that LEFT JOIN is a native part of Cayenne Expression package, I
wonder if we should get rid of JOINT vs. DISJOINT prefetches and
always create a left outer join for each prefetch, and add prefetched
table columns to the query
The advantages are:
1. Simplify prefetching from the user perspective (back to Cayenne 1.1
API)
2. Instantly free the users from thinking about prefetching caveats
like CAY-1025, and others.
3. (Probably) allow us to use the same algorithm for prefetching with
SelectQuery and EJBQLQuery.
Am I missing something? Any reason why we don't want to use a
"universal prefetch" via an outer join, and deprecate the distinction
between JOINT and DISJOINT?
Testing the performance should be real easy I think - change the JOINT
prefetch resolver to resolve as OUTER JOIN and compare it with
DISJOINT performance - something I may try soon (prerequisite being
CAY-802 - we want prefetched joins to be separate from the qualifier
joins).
Andrus
