zoukankan      html  css  js  c++  java
  • Oracle中drop user和drop user cascade的区别

    drop user ; 仅仅是删除用户,drop user username cascade ;会删除此用户名下的所有表和视图。

    user
    Specify the user to be dropped. Oracle Database does not drop users whose schemas contain objects unless you specify CASCADE or unless you first explicitly drop the user's objects.

    CASCADE
    Specify CASCADE to drop all objects in the user's schema before dropping the user. You must specify this clause to drop a user whose schema contains any objects.

    使用cascade参数可以删除该用户的全部objects。要说明的如下:
    1. If the user's schema contains tables, then Oracle Database drops the tables and automatically drops any referential integrity constraints on tables in other schemas
    that refer to primary and unique keys on these tables.

    如果用户的schema中有表,则在删除表的时候自动删除与该表相关的主键和外键。

    2. If this clause results in tables being dropped, then the database also drops all domain indexes created on columns of those tables and invokes appropriate drop
    routines.
    如果用户的schema中有表,则在删除表的时候自动删除与该表相关的索引。


    3. Oracle Database invalidates, but does not drop, the following objects in other schemas:
    删除用户时,下列在其他用户中的objects不会被删除,只会被置为无效

    Views or synonyms for objects in the dropped user's schema
    视图,同义词

    Stored procedures, functions, or packages that query objects in the dropped user's schema
    存储过程,函数,包

    Oracle Database does not drop materialized views in other schemas that are based on tables in the dropped user's schema. However, because the base tables no longer exist, the materialized views in the other schemas can no longer be refreshed.
    其他用户建立的基于被删除用户的物化视图不会被删除,只是不能在刷新了。

    Oracle Database drops all triggers in the user's schema.
    用户模式下的所有触发器全部被删除

    Oracle Database does not drop roles created by the user.
    被删除用户建立的其他用户不会被删除

  • 相关阅读:
    Spring框架中的单例bean是线程安全的吗?
    Spring Cloud 解决了哪些问题?
    服务端处理 Watcher 实现 ?
    内部类可以引用它的包含类(外部类)的成员吗?有没有什么限制?
    vue-router点击同一个页面异常处理
    mybatis代码生成+自定义注解+自定义注释
    lombok使用
    idea格式化设置
    寒假每周总结4
    寒假每日日报27
  • 原文地址:https://www.cnblogs.com/rusking/p/4533548.html
Copyright © 2011-2022 走看看