Message Title

When a cached PersistentBag is read, its contents are read one-by-one eagerly, even if the corresponding entity has a @BatchSize. PersistentBag.initializeFromCache calls ManyToOneType.assemble for every record. This ManyToOneType is constructed org.hibernate.mapping.OneToMany.getEntityType(), which always specifies false for the 'lazy' property.

Initializing a cached collection should at least respect the @BatchSize annotation of the corresponding entity, but perhaps it should not even load the entities eagerly if the OneToMany has FetchType.LAZY.

I've created a demo-case for this problem (a patch on top of the 4.3 branch). Unfortunately, I do not know how to assert on actual queries, but you can see the problem in the log:

14:15:06,796 DEBUG AbstractReadWriteAccessStrategy:34 - getting key[org.hibernate.test.cache.Company.users#1] from region[hibernate.test.org.hibernate.test.cache.Company.users]
14:15:06,796 DEBUG BaseGeneralDataRegion:46 - Cache[hibernate.test.org.hibernate.test.cache.Company.users] lookup : key[org.hibernate.test.cache.Company.users#1]
14:15:06,796 DEBUG BaseGeneralDataRegion:52 - Cache[hibernate.test.org.hibernate.test.cache.Company.users] hit: org.hibernate.test.cache.Company.users#1
14:15:06,796 DEBUG AbstractReadWriteAccessStrategy:41 - hit key[org.hibernate.test.cache.Company.users#1] in region[hibernate.test.org.hibernate.test.cache.Company.users]
14:15:06,796 DEBUG SQL:109 - 
    select
        user0_.id as id1_1_0_,
        user0_.company_id as company_2_1_0_ 
    from
        "User" user0_ 
    where
        user0_.id=?
14:15:06,796 TRACE BasicBinder:81 - binding parameter [1] as [INTEGER] - [1]
14:15:06,797 TRACE BasicExtractor:78 - extracted value ([company_2_1_0_] : [INTEGER]) - [1]
14:15:06,798 DEBUG SQL:109 - 
    select
        user0_.id as id1_1_0_,
        user0_.company_id as company_2_1_0_ 
    from
        "User" user0_ 
    where
        user0_.id=?
14:15:06,798 TRACE BasicBinder:81 - binding parameter [1] as [INTEGER] - [2]
14:15:06,798 TRACE BasicExtractor:78 - extracted value ([company_2_1_0_] : [INTEGER]) - [1]
14:15:06,799 DEBUG SQL:109 - 
    select
        user0_.id as id1_1_0_,
        user0_.company_id as company_2_1_0_ 
    from
        "User" user0_ 
    where
        user0_.id=?
14:15:06,799 TRACE BasicBinder:81 - binding parameter [1] as [INTEGER] - [3]