来自PostgreSQL文档:

A database contains one or more named schemas, which in turn contain tables. Schemas also contain other kinds of named objects, including data types, functions, and operators. The same object name can be used in different schemas without conflict; for example, both schema1 and myschema can contain tables named mytable. Unlike databases, schemas are not rigidly separated: a user can access objects in any of the schemas in the database he is connected to, if he has privileges to do so. There are several reasons why one might want to use schemas: To allow many users to use one database without interfering with each other. To organize database objects into logical groups to make them more manageable. Third-party applications can be put into separate schemas so they do not collide with the names of other objects. Schemas are analogous to directories at the operating system level, except that schemas cannot be nested.

在oracle中，Schema是一个数据库下的一个用户，例如scott是orcl数据库中的一个模式。 在一个数据库中，我们可能有很多像scott这样的模式

schema包含数据库。

数据库是Schema的一部分。

schema >数据库。

模式包含视图、存储过程、数据库、触发器等。

我试着根据我对以下类比的理解来回答:

A database is like the house In the house there are several types of rooms. Assuming that you're living in a really big house. You really don't want your living rooms, bedrooms, bathrooms, mezzanines, treehouses, etc. to look the same. They each need a blueprint to tell how to build/use them. In other words, they each need a schema to tell how to build/use a bathroom, for example. Of course, you may have several bedrooms, each looks slightly different. You and your wife/husband's bedroom is slightly different from your kids' bedroom. Each bedroom is analogous to a table in your database. A DBMS is like a butler in the house. He manages literally everything.

As https://www.informit.com/articles/article.aspx?p=30669

所有对象的名称在一定范围内必须是唯一的。每一个 数据库必须有唯一的名称;模式名称不能重复 在单个数据库的范围内，表的名称必须为 在单个模式的作用域中是唯一的，列名必须是 在表中是唯一的。类中索引的名称必须唯一 数据库。

数据库模式是对表、视图、存储过程等对象进行逻辑分组的一种方式。把模式看作是对象的容器。 表是行和列的集合。 所有表的组合构成一个db。