SQL View Management 3

Question 1

An aggregate view using GROUP BY and SUM is typically what kind of view?

Accepted Answer

Non-updatable

Answer

Views containing aggregation cannot be directly updated because rows do not map one-to-one.

Question 2

Which command refreshes the stored data of a materialized view in many databases?

Accepted Answer

REFRESH MATERIALIZED VIEW

Answer

REFRESH MATERIALIZED VIEW re-executes the underlying query and updates the cache.

Question 3

A view that references another view is best described as a what?

Accepted Answer

Nested view

Answer

Views can be layered on top of other views, forming nested views.

Question 4

What is a key benefit of using views to simplify complex joins?

Accepted Answer

Users query one named object instead of rewriting the join

Answer

Views encapsulate complex logic so users can query a simple name.

Question 5

Which clause renames the columns exposed by a view?

Accepted Answer

Specifying a column list after the view name

Answer

Listing column names in CREATE VIEW v (col1, col2) renames output columns.

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