ANSWER

While the business analyst usual works in the logical domain, understanding what a database view is and the advantages of using them can be helpful when the analyst is tasked with documenting requirements and creating specifications for reports and user interfaces that present data from database queries.

A database view is a stored query that returns data from one or more database tables.  The stored query, or view, is a virtual table.   Once you have defined a view, you can reference it just as you would any other table in a database.  Since the view is the result of a stored query, it does not contain a copy of the data itself.  Instead, it references the data in the underlying base tables. 

Views provide a number of advantages:

• A view can provide additional security.  By creating a view and creating the necessarily privileges, you can ensure that the users are only able to retrieve and modify data that is exposed by that view.  Users will not be able to see or access data in the underlying tables that is not exposed by the view.
• Views can reduce query complexities.  By creating and storing complex queries and exposing them in the form of a view, the data from the view can be extracted using much simpler queries.
• Since a database view is a stored query, not a copy of the actual data, views consume very little space. 

Some examples of the ways views are used are:

• To combine data from multiple tables into a single virtual table that can be queried using basic statements.
• To partition a complex table into multiple virtual tables that are simpler to query. For example, if a database table contains sales data from the past 10 years, views can be created and represented using tables names such as SalesData2020 or SalesData2021.
• To aggregate data and perform calculations.  The view (stored query) can request the database engine to sum or average data in underlying tables.  These sums or averages can then be queried more easily.