Database - Physical Database Design MCQs Part

1. If a denormalization situation exists with a one-to-one binary relationship, which of the following is true?

A.
All fields are stored in one relation.
B.
All fields are stored in two relations.
C.
All fields are stored in three relations.
D.
All fields are stored in four relations.

 Answer Option A

2. Selecting a data type involves which of the following?

A.
Maximize storage space
B.
Represent most values
C.
Improve data integrity
D.
All of the above.

 Answer Option C

3. What is the best data type definition for Oracle when a field is alphanumeric and has a length that can vary?

A.
VARCHAR2
B.
CHAR
C.
LONG
D.
NUMBER

 Answer Option A

4. If a denormalization situation exists with a many-to-many or associative binary relationship, which of the following is true?

A.
All fields are stored in one relation.
B.
All fields are stored in two relations.
C.
All fields are stored in three relations.
D.
All fields are stored in four relations.

 Answer Option B

5. Which of the following is an advantage of partitioning?

A.
Complexity
B.
Inconsistent access speed
C.
Extra space
D.
Security

 Answer Option D

6. The blocking factor is:

A. a group of fields stored in adjacent memory.
B. the number of physical records per page.
C. attributes grouped together by the same primary key.
D. attributes grouped together by the same secondary key.

 Answer Option B

7. Which of the following improves a query's processing time?

A. Write complex queries.
B. Combine a table with itself.
C. Query one query within another.
D. Use compatible data types.

 Answer Option D

8. Which of the following are integrity controls that a DBMS may support?

A. Assume a default value in a field unless a user enters a value for that field.
B. Limit the set of permissible values that a field may assume.
C. Limit the use of null values in some fields.
D. All of the above.

 Answer Option D

9. Which of the following is not a factor to consider when switching from small to large block size?

A. The length of all of the fields in a table row.
B. The number of columns
C. Block contention
D. Random row access speed

 Answer Option B

10. What is the best data type definition for Oracle when a field is alphanumeric and has a fixed length?

A. VARCHAR2
B. CHAR
C. LONG
D. NUMBER

 Answer Option B

11. A secondary key is which of the following?

A. Nonunique key
B. Primary key
C. Useful for denormalization decisions
D. Determines the tablespace required

 Answer Option A

12. The fastest read/write time and most efficient data storage of any disk array type is:

A. RAID-0.
B. RAID-1.
C. RAID-2.
D. RAID-3.

 Answer Option A

13. A rule of thumb for choosing indexes for a relational database includes which of the following?

A. Indexes are more useful on smaller tables.
B. Indexes are more useful for columns that do not appear frequently in the WHERE clause in queries.
C. Do not specify a unique index for the primary key of each table.
D. Be careful indexing attributes that have null values.

 Answer Option D

14. Sequential retrieval on a primary key for sequential file storage has which of the following features?

A. Very fast
B. Moderately fast
C. Slow
D. Impractical

 Answer Option A

15. A multidimensional database model is used most often in which of the following models?

A. Data warehouse
B. Relational
C. Hierarchical
D. Network

 Answer Option A

6. The blocking factor is:

A. a group of fields stored in adjacent memory.
B. the number of physical records per page.
C. attributes grouped together by the same primary key.
D. attributes grouped together by the same secondary key.

 Answer Option B

7. Which of the following improves a query's processing time?

A. Write complex queries.
B. Combine a table with itself.
C. Query one query within another.
D. Use compatible data types.

 Answer Option D

8. Which of the following are integrity controls that a DBMS may support?

A. Assume a default value in a field unless a user enters a value for that field.
B. Limit the set of permissible values that a field may assume.
C. Limit the use of null values in some fields.
D. All of the above.

 Answer Option D

9. Which of the following is not a factor to consider when switching from small to large block size?

A. The length of all of the fields in a table row.
B. The number of columns
C. Block contention
D. Random row access speed

 Answer Option B

10. What is the best data type definition for Oracle when a field is alphanumeric and has a fixed length?

A. VARCHAR2
B. CHAR
C. LONG
D. NUMBER

 Answer Option B

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