Hi Tom,
attached is a fix for issue 860: Running out of memory--JOINED
Inheritance w/ secondary table
The problem is basically that the generated query is missing joins for
the tables of the JOINED inheritance, only the join for the secondary
table is there.
I modified two classes:
ExpressionBuilder:
moved
> if (isUsingOuterJoinForMultitableInheritance() &&
(!getSession().getPlatform().shouldPrintOuterJoinInWhereClause())) {
>
normalizer.getStatement().getOuterJoinExpressions().addElement(null);
>
normalizer.getStatement().getOuterJoinedMappingCriteria().addElement(null);
>
normalizer.getStatement().getOuterJoinedAdditionalJoinCriteria().addElement(additionalExpressionCriteriaMap());
>
normalizer.getStatement().getDescriptorsForMultitableInheritanceOnly().add(this.getDescriptor());
> // fall through to the main case
...
out of the
if (!this.wasAdditionJoinCriteriaUsed &&
this.queryClass != null) {
check. Above lines seems to initiate the addition of joins for the
inheritance tables to the query, and should be *always* executed.
SQLSelectStatement:
The secondary table ORDER_SEC is not contained in the Map
"tablesJoinExpressions", as this map only contains outer joined tables.
So the statement
Expression onExpression =
(Expression)tablesJoinExpressions.get(table);
returns null.
As I'm not totally sure, how outer joins for inheritance and secondary
tables are processed by TopLink, this is my best guess of fixing issue
860. It would be great, if somebody for the TopLink team could give me
more inside into these two topics. Maybe somebody could educate me over
the phone...
With the fix, the correct SQL query is generated, and
entity-persistence-tests pass against Derby.
Thanks,
-- markus.