Berkeley DB

Why Transactions?

Perhaps the first question to answer is “Why transactions?” There are a number of reasons to include transactional support in your applications. The most common ones are the following:

• Recoverability Applications often need to ensure that no matter how the system or application fails, previously saved data is available the next time the application runs.

• Deadlock avoidance When multiple threads of control change the database at the same time, there is usually the possibility of deadlock; that is, each of the threads of control owns a resource that another thread wants, so no thread is able to make forward progress—all waiting for a resource. Deadlocks are resolved by having one of the operations involved release the resources ...