Microsoft® SQL Server 2012 Unleashed

User/Schema Separation

The changes to schema security introduced in SQL Server 2005 are still valid in SQL Server 2012. Versions of SQL Server before SQL Server 2005 had schemas, but they did not conform to the American National Standards Institute (ANSI) definition of schemas. ANSI defines a schema as a collection of database objects that one user owns and that forms a single namespace. A single namespace is one in which each object name is unique and there are no duplicates. So, for example, if you have two tables named customer, they cannot exist in the same namespace.

To fully understand the user/schema separation, you need to understand how schemas were used in prior versions of SQL Server. In SQL Server 7.0 and 2000, a default schema was ...