1Z0-006 Database Objects and Constraints 3

Question 1

What is the primary purpose of an index in Oracle Database?

Accepted Answer

To speed up data retrieval operations on a table

Answer

To enforce data uniqueness in a column

Answer

To create a relationship between two tables

Answer

To prevent unauthorized access to data

Question 2

Which type of index does Oracle automatically create when you define a PRIMARY KEY constraint?

Accepted Answer

Unique B-tree index

Answer

Bitmap index

Answer

Function-based index

Answer

Composite non-unique index

Question 3

What is a composite index in Oracle Database?

Accepted Answer

An index that spans two or more columns of a table

Answer

An index created on a virtual computed column

Answer

An index built on an expression like UPPER(column)

Answer

An index that permits duplicate values

Question 4

When should you consider dropping an index in Oracle Database?

Accepted Answer

When the index is rarely used by queries but causes significant overhead on DML operations

Answer

Whenever the table exceeds one million rows

Answer

When the indexed column has high cardinality

Answer

When the table already has a primary key constraint

Question 5

Which statement about indexes and DML operations in Oracle Database is TRUE?

Accepted Answer

Oracle automatically updates all indexes when DML operations modify indexed column values

Answer

Indexes have no effect on INSERT performance

Answer

Indexes must be manually rebuilt after every UPDATE statement

Answer

DELETE operations do not affect existing indexes

Question 6

What is a function-based index in Oracle Database?

Accepted Answer

An index built on the result of an expression or function applied to one or more columns

Answer

An index Oracle builds automatically when a built-in function is used

Answer

An index that can only be used with aggregate functions like SUM

Answer

An index stored as a separate PL/SQL function object

Question 7

In which scenario is a bitmap index most appropriate in Oracle Database?

Accepted Answer

A column with low cardinality such as a status flag or gender code

Answer

A column with millions of distinct values such as a national ID number

Answer

A column that is frequently updated in a high-transaction OLTP environment

Answer

A primary key column that must enforce uniqueness