Views
A view can be seen as a named query, or as a wrapper around a SELECT
statement. Views are essential building blocks of relational databases from the UML modeling perspective; a view can be thought of as a method for a UML class. Views share several advantages with procedures, so the following benefits are shared between views and stored procedures. Views can be used for the following purposes:
- Simplifying complex queries and increasing code modularity
- Tuning performance by caching the view results for later use
- Decreasing the amount of SQL code
- Bridging the gap between relational databases and OO languages, especially updatable views
- Implementing authorization at the row level by leaving out rows that do not meet a certain predicate
- Implementing interfaces and the abstraction layer between high-level languages and relational databases
- Implementing last-minute changes
A view should meet the current business needs instead of potential future business needs. It should be designed to provide a...