Are Views automatically updated

Dive into views: Mechanics and implications

Lifecycle of the data in views

Views are essentially stored queries, not containers for data. Thus, they don't cache data or hold a static dataset. Each time a view is accessed, it runs the underlying query, retrieving the latest data present in the base tables, including all recent inserts, updates, and deletes.

Performance factors: The devil in details

Views can simplify complex queries, but can also be taxing on database performance. Complex views, especially those involving intricated joins or heavy aggregations, may be costly. Stick with explicit columns instead of SELECT * and consider the judicious use of indexed views.

Indexed views: Binary blessing in disguise

Indexed views store a particular result set and can boost query performance. However, they're not always the best choice, especially for frequently changing data. An index needs to be updated in sync with the data, which can add overhead to write operations.

Refreshing views: Refreshments needed?

If you modify the schema or structure of the underlying tables, explicitly refreshing the view with the sp_refreshview command aligns the view with those changes. Otherwise, the view keeps displaying the most up-to-date snapshot of the underlying tables without extra input.

Practicalities: Banking on views

Views can encapsulate business logic, present a consistent and simplified interface to potentially complex underlying data structures, and help implement an additional layer of security. However, make sure your views are efficient and maintainable.

The nitty-gritty of views

Designing with views

Views help us to abstract the underlying database schema and provide a simplified and consistent interface for client applications. Proper application of views can lead to a more robust architecture and maintainable codebase.

Altering views: Handle with care

When making updates inside a view, always consider possible ripple effects. Other views may be based on the modified view, and changes could break dependencies. It is advised to test all changes in a non-production environment beforehand.

Schema changes: The trickster's trap

Unexpectedly, views don't automatically adapt to schema changes. If a column is added to or removed from a table, the view will not include these changes until it's manually refreshed or altered using the ALTER VIEW or sp_refreshview commands.

Scaling vertically: Views in high gear

For high-performance systems, optimizing view queries is crucial. Particularly for systems with high data-access concurrency, it's essential to consider how the view's execution plan is generated and how indexing on base tables can benefit performance.