In the current project we faced the problem of concurrent changes to database, for the data that should be accessed sequentially. Imagine you have the customer’s bank account where he can withdraw the money. If the customer is not a person, but company, and if he can have multiple users accessing the bank application, without any locks there’s a chance for situation where two or more users depute transfers, that exceed the account balance, but because data is accessed concurrently, they both can make payoff.
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Read the full articleHibernate and its way of associations mapping can be a bit hard to understand for beginners. Unidirectional and bidirectional mapping, cascade save, relation owner… How to construct correctly associations between objects to get desired effect? A short introduction based on OneToMany parent-child relation.
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