What updates when there are any changes to its source data?

What updates when there are any changes to its source data?

• A. Views/materialized views
• B. Relational databases
• C. Stored procedures
• D. Trigger functions

Answer: (A)

The correct choice is views/materialized views because they are specifically designed to provide a way of querying data dynamically based on the underlying source data. A view is essentially a virtual table that presents data from one or more tables as if it were a single table, and it updates automatically whenever the source data changes. This means that any queries executed against the view will reflect the current state of the underlying data without the need for manual updates or refreshing.

Materialized views, on the other hand, are a physical copy of data that are stored on disk and can enhance the performance of complex queries. However, they require a refresh operation to reflect changes in the source data. Despite this need for updates, they still conceptually serve a similar purpose regarding data integrity and availability as views, though they do so in different contexts.

While relational databases manage the overall data structure and facilitate data interactions, they do not themselves automatically update in response to changes in source data without the presence of views or triggers involved in the process.

Stored procedures are precompiled SQL statements that can be executed in the database, but they do not inherently respond to changes in real time and would need to be explicitly called to run against the modified data.

Trigger functions are mechanisms designed to automatically execute specified actions