bulk update of entities

Support
#1

Hi guys, May someone post sample how to correctly update eg. 1k entities ?
I tried sth like this -> [pseudo]


try(Transaction t){
    getEntityManager
    Query q = getEntities
    Entities=  q.getResultList
    loop Entity from Entities{
        Entity.setNewState(state)
        EntityManager.merge(Entity)
        .....
        Query q = EntityManager.createNativeQuery(UPDATE STATEMENT)
        q.executeUpdate()
    }
    t.commit
}

I always endup in loop with ResultSet closed or EntityManager closed errors. I guess it is caused due to long runing transaction. Creating separate transaction for each entity update is way to go ? Or commitRetaining method ?
Thank you for any comment.

#2

I would recommend committing transaction after some number of repetitions. Something like this:

int i = 0;
try(Transaction t){
    getEntityManager
    Query q = getEntities
    Entities=  q.getResultList
    loop Entity from Entities{
        Entity.setNewState(state)
        EntityManager.merge(Entity)
        .....
        Query q = EntityManager.createNativeQuery(UPDATE STATEMENT)
        q.executeUpdate()
        if (i % 100 == 0) {
            t.commitRetaining();
            getEntityManager // this is required because a new tx has been started
        }
        i++;
    }
    t.commit
}