Framework/ORM
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Object Relation Mapping(ORM) and HibernateFramework/ORM 2020. 7. 9. 22:28
1. Overview Object Relation Mapping(ORM) provides a simple API for storing and retrieving Java objects directly to and from the database. 2. Features Non-intrusive: No need to follow specific rules or design patterns Transparent: Your object model is unaware 3. Advantages of ORM 3.1 Productivity Eliminates lots of repetitive code – focus on business logic – Database schema is generated automatic..
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N+1 ProblemFramework/ORM 2020. 4. 10. 16:23
1. Overview N+1 problem is a performance issue in Object Relational Mapping that fires multiple select queries (N+1 to be exact, where N= number of records in a table) in a database for a single select query at the application layer. 2. Problem To understand N+1 problem, let's consider a scenario. Let’s say we have a collection of User objects mapped to t_users table in a database, and each user..