How does Hibernate guarantee application-level repeatable reads
Introduction In my previous post I described how application-level transactions offer a suitable concurrency control mechanism for long conversations. All entities are loaded within the context of a Hibernate Session, acting as a transactional write-behind cache. A Hibernate persistence context can hold one and only one reference to a given entity. The first level cache guarantees session-level repeatable reads. If the conversation spans over multiple requests we can have application-level repeatable reads. Long conversations are inherently stateful so we can opt for detached objects or long persistence contexts. But application-level repeatable reads… Read More
MongoDB Incremental Migration Scripts
Introduction An incremental software development process requires an incremental database migration strategy. I remember working on an enterprise application where the hibernate.hbm2ddl.auto was the default data migration tool. Updating the production environment required intensive preparation and the migration scripts were only created on-the-spot. An unforeseen error could have led production data corruption. Incremental updates to the rescue The incremental database update is a technical feature that needs to be addressed in the very first application development iterations. We used to develop our own custom data migration implementations and spending time on writing/supporting… Read More
