Oracle Database SQL — Question 112

Which two statements are true about indexes and their administration in an Oracle database? (Choose two.)

Answer options

• A. A new index can be created or an existing one reused when a primary key constraint is created.
• B. An INVINSIBLE index is maintained by DML operations on the underlying table.
• C. If a query filters on an indexed column, the index will always be accessed during execution of the query.
• D. A DROP INDEX statement always prevents updates to the table during the drop operation.
• E. The same table column cannot be part of a unique and non-unique index.

Correct answer: A, B

Explanation

Option A is correct because creating a primary key constraint can utilize an existing index or create a new one. Option B is also correct as an INVISIBLE index is still maintained by DML operations despite not being used in query plans. Options C, D, and E are incorrect since an index may not always be accessed, a DROP INDEX does not prevent updates, and a column can be part of both unique and non-unique indexes.