1. DMVs and DMFs
动态
2. Catalog Views
持久化视图，例如 sys.objects，sys.databases
3. Compatibility Views
纯粹为了兼容，例如 sysfiles，sysindexes，sysobjects
4.Information Schema Views
为了跟SQL 92兼容而搞的一套视图，都在INFORMATION_SCHEMA下
5. System Functions
一堆属性函数
SERVERPROPERTY
COLUMNPROPERTY
DATABASEPROPERTY (deprecated in favor of the following function)
DATABASEPROPERTYEX
INDEXPROPERTY
INDEXKEY_PROPERTY
OBJECTPROPERTY (deprecated)
OBJECTPROPERTYEX
SQL_VARIANT_PROPERTY
FILEPROPERTY
FILEGROUPPROPERTY
TYPEPROPERTY
6.System Stored Procedures
[@more@]
