Views in DBMS

 


Views in DBMS 


With this functionality, the DBMS is an extremely powerful and useful tool. However, as the end-users are not too interested in how complex or easy a task is for the system, it could be argued that the DBMS has made things more complex because they now see more data than they actually need or want .



Views provide a level of security

Views can be set up to exclude data that some users should not see. For example, we could create a view that allows a branch manager and the Payroll Department to see all staff data, including salary details, and we could create a second view that other staff would use that excludes salary details.


Views provide a mechanism to customize the appearance of the database

For example, the Contracts Department may wish to call the monthly rent field (rent) by the more obvious name, Monthly Rent.


A view can present a consistent, unchanging picture of the structure of the database

even if the underlying database is changed (for example, fields added or removed, relationships changed, files split, restructured, or renamed). If fields are added or removed from a file, and these fields are not required by the view, the view is not affected by this change. Thus, a view helps provide the program–data independence we mentioned in the previous section.

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