Thursday, March 15, 2012

CRM and data mining Day 06

What is views?

A view is a stored database query that provides a database user with a customized subset of the data from one or more tables in the database. Said another way, a view is a virtual table because it looks like a table and for the most part behaves like a table, yet it stores no data (only the defining query is stored).


Views serve a number of useful functions:

  1. Hiding columns that the user does not need to see (or should not be allowed to see)
  2. Hiding rows from tables that a user does not need to see (or should not be allowed to see)
  3. Hiding complex database operations such as table joins
  4. Improving query performance (in some RDBMSs, such as Microsoft SQL Server)


How to create views in SQL Server?


Could you find out which objects (tables/dimensions) a fact table depend on?


References
Andy Oppel (2011), Database Demystified, 2nd Ed, McGraw-Hill.

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