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65288a64fe Views can represent a subset of the data contained in a table. A view is equivalent to its source query. FROM tablecustomers c JOIN accountstable a ON a.customerid = c.customerid ) . Introducing the new Surface family. INSERT, UPDATE, and DELETE operations can be performed on updatable views. Version:1.0File Name:SQLServer2012SystemViewsMap.pdfSQLServer2012SystemViewsMap.xpsDate Published:5/30/2013File Size:1.4 MB283 KB The Microsoft SQL Server 2012 System Views Map shows the key system views included in Microsoft SQL Server 2012, and the relationships between them.
They give a static snapshot of the data and may include data from remote sources. Without the use of views, the normalization of databases above second normal form would become much more difficult. v t e Database management systems Types Object-oriented comparison Relational comparison Document-oriented Graph NoSQL NewSQL Concepts Database ACID Armstrong's axioms CAP theorem CRUD Null Candidate key Foreign key Superkey Surrogate key Unique key Objects Relation table column row View Transaction Transaction log Trigger Index Stored procedure Cursor Partition Components Concurrency control Data dictionary JDBC XQJ ODBC Query language Query optimizer Query plan Functions Administration and automation Query optimization Replication Related topics Database models Database normalization Database storage Distributed DBMS Federated database system Referential integrity Relational algebra Relational calculus Relational database Relational DBMS Relational model Object-relational database Transaction processing . Nevertheless, some DBMS (such as Oracle Database) do not abide by this SQL standard restriction. Views can join and simplify multiple tables into a single virtual table. Therefore, an ORDER BY clause in the view definition is meaningless; the SQL standard (SQL:2003) does not allow an ORDER BY clause in the subquery of a CREATE VIEW command, just as it is refused in a CREATE TABLE statement. In another parallel with functions, database users can manipulate nested views, thus one view can aggregate data from other views. Just as a function (in programming) can provide abstraction, so can a database view. The RDBMS then takes the simple query, replaces the equivalent view, then sends the following to the query optimizer:. PostgreSQL implemented materialized views in its 9.3 release.