Views can be used to simplify data access. Common queries that utilize complex joins,
UNION queries, and more involved SQL can be defined as views. This minimizes the amount of complex code that must be written or rewritten and provides a simple way of organizing your common data access.
SQL Server 2012 comes with a set of system views that demonstrate the views’ capability to mask complex queries and simplify data manipulation. These system views include catalog views, information schema views, and compatibility views. In many cases, the definition of these views is hidden, but some of them can be analyzed using the
sp_helptext system procedure. For example,
sys.triggers, a catalog view defined in SQL Server 2012, ...