Views in SQL are virtual tables created from a query, designed to simplify complex queries and improve data management. However, their impact on time efficiency depends on how they are implemented and used.

Performance of Standard Views

Standard views do not inherently improve query performance. When a query references a view, the database engine expands the view into its underlying query at runtime. This means the performance of a query using a standard view is generally equivalent to executing the underlying query directly. For example, querying a view without indexes or optimizations may not yield any time efficiency gains.

Indexed Views

Indexed views, also known as materialized views in some databases, can significantly enhance performance. When a unique clustered index is created on a view, the result set is materialized and stored physically in the database. This eliminates the need to recompute the view's query at runtime, reducing execution time for frequently accessed data. For instance: