幂等性-Idempotency

最新推荐文章于 2025-08-12 16:04:27 发布

原创最新推荐文章于 2025-08-12 16:04:27 发布 · 448 阅读

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#idempotent #database #variables #processing #system #stream

幂等性是指同一操作可以被重复执行而不会改变结果的特性。本文介绍了幂等性的定义及其在计算机科学中的应用，特别是在数据库查询及事件流处理中如何确保操作的安全性和一致性。

幂等性描述的是这种操作属性：一个操作做多次，产生同样的结果。这个概念来自于抽象代数，在计算机科学中有重要用途。

In computer science, the term idempotent is used to describe methods or subroutine calls that can safely be called multiple times, as invoking the procedure a single time or multiple times results in the system maintaining the same state; i.e., after the method call all variables have the same value as they did before.

Example: Looking up some customer's name and address in a database are typically idempotent, since this will not cause the database to change. Placing an order for a car for the customer is not idempotent, since running the method/call several times will lead to several orders being placed, and therefore the state of the database being changed to reflect this.

In Event Stream Processing, idempotence refers to the ability of a system to produce the same outcome, even if an event or message is received more than once.