mysql、orcl中database、schema、user之间的关系

对于MySQL而言，“database 数据库” 和 “schema 模式” 是同一件事。具体区分如下表：

In MySQL:
server instance == not identified with catalog, just a set of databases
database == schema == catalog == a namespace within the server.
user == named account, who can connect to server and use (but can not own - no concept of ownership) objects in one or more databases
to identify any object you need (database name + object name)

 

In Oracle:
server instance == database == catalog == all data managed by same execution engine
schema == namespace within database, identical to user account
user == schema owner == named account, identical to schema, who can connect to database, who owns the schema and use objects
possibly in other schemas
to identify any object you need (schema name + object name)

 

详细阅读：

1.What's
the difference between a catalog and a schema in a relational database?

2.Relationship
between catalog, schema, user, and database instance