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Transaction management belongs logically in the service layer. Spring supports two primary approaches: Programmatic transaction management (for advanced use cases) Declarative transaction management (recommended for most applications) Declarative transactions can be implemented either via XML configuration or annotations — the latter being th ...

Database Recovery and Consistency RPO (Recovery Point Objective) Recovery Point Objective (RPO) defines the maximum acceptable amount of data loss measured in time. For example, an RPO of 4 hours means that in the event of a failure, the system can be restored to a state no older than 4 hours before the failure occurred. Databases achieving RPO ...

In database theory, the concept of a 'multi-threaded transaction' is fundamentally contradictory. To understand why, one must look at the ACID properties—specifically Isolation. Transactions are designed to operate within an isolated context, typically managed by thread-local storage in frameworks like Spring. Each thread maintains its own data ...

Declaring @Transactional alone does not trigger transactional behavior; you must activate the declarative transaction infrastructure explicitly. In a Java-based configuration, annnotate a @Configuration class with @EnableTransactionManagement and expose a PlatformTransactionManager bean. The proxyTargetClass attribute (or proxy-target-class in ...

Views in MySQL Views are virtual tables that don't占用 any physical storage. When querying a view, MySQL retrieves data dynamically from the underlying base tables. Key Characteristics Modifications to a view propagate to the underlying base tables Changes to base tables are visible through the view when querying Views typically shouldn't be m ...