Question 1

Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. Denormalization ____.

Accepted Answer

Denormalization involves combining the data in the two tables into one table, creating a less normalized but potentially more efficient structure for querying data. It does not create a third table or additional repeating groups, and although it may involve adding additional indexes, this is not the primary goal of denormalization.

Question 2

One of the reasons for having secondary memory is that primary memory cannot possibly hold all of a company's programs and data.

Accepted Answer

Primary memory (RAM) has limited storage capacity, whereas secondary memory (hard drives, flash drives, etc.) can hold much more data and programs. Therefore, companies often use secondary memory to store their large amounts of data and programs that cannot fit in primary memory.

Question 3

Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. The primary key of Table A has been placed in Table B as a foreign key. The substituting foreign keys physical database design technique ____.

Accepted Answer

The substituting foreign keys physical database design technique can only be performed if Table A has more than one candidate key. This is because the foreign key in Table B must be able to uniquely identify a row in Table A, and if Table A has only one candidate key, then the foreign key in Table B will not be able to do this.

Question 4

The drawback of denormalization is that it ____.

Accepted Answer

Denormalization introduces data redundancy, which can lead to data inconsistency and increased storage requirements.

Question 5

The storing derived data physical database design technique is designed to ____.

Accepted Answer

The answer of The storing derived data physical database design...

Question 6

Horizontal partitioning ____.

Accepted Answer

Horizontal partitioning involves dividing the rows of a table into groups and storing them separately, which matches option A.

Question 7

The common advantage of separating portions of a table's data using either horizontal or vertical partitioning is that ____.

Accepted Answer

Partitioning a table, whether horizontally or vertically, allows data to be stored more efficiently in a concentrated space on the disk. This organization can significantly speed up data retrieval operations, especially for queries that target specific partitions. This is because the system can quickly locate and access the relevant partition without having to scan the entire table.

Question 8

Denormalization can improve the ____.

Accepted Answer

Denormalization can improve the performance of the database by reducing the number of join operations. However, it may also introduce redundancy and potentially impact data integrity and accuracy. Therefore, options B and C are not always true.

Question 9

If the primary key of a table is clumsy because it has too many attributes and is replaced by a new, single attribute key, ____.

Accepted Answer

When a new, single attribute key is introduced to replace a cumbersome primary key, it becomes the new primary key of its own table. Additionally, it should replace the old primary key wherever it was used as a foreign key, regardless of whether the relationships were one-to-many or many-to-many. This ensures consistency and integrity in the database schema.

Question 10

Programs and data are loaded into primary memory from secondary memory when they are required for processing.

Accepted Answer

This statement is true. Primary memory, also known as RAM (Random Access Memory), is used for temporary storage of programs and data while they are being processed by the CPU. Secondary memory, such as hard drives and solid-state drives, is used for long-term storage of files and programs that are not currently in use. When a program or file is needed for processing, it is loaded from secondary memory into primary memory.

Question 11

Tracks are concentric circles of data on a recording surface of a disk.

Accepted Answer

Tracks are indeed concentric circles of data on a recording surface of a disk.

Question 12

Vertical partitioning ____.

Accepted Answer

Vertical partitioning involves dividing the columns of a table into groups (choice B) and may involve splitting large text attributes off from the rest of a table (choice C), storing these groups separately to improve performance and manageability.

Question 13

The advantage of using the substituting foreign keys physical database design technique is that it is designed to ____.

Accepted Answer

The substituting foreign keys physical database design technique is designed to reduce the number of joins required in a query by replacing large, clumsy keys with foreign keys that reference smaller tables. This technique does not necessarily reduce the number of indexes or attributes in the keys. Therefore, option A is the correct choice.

Question 14

The clustering files physical database design technique ____.

Accepted Answer

Clustering files in a database are designed to improve the performance of join operations by storing related records from different tables close to each other on the disk, reducing the time needed to access and join them.

Question 15

Combining two tables that represent a one-to-one relationship ____.

Accepted Answer

The answer of Combining two tables that represent a one-to-one...

Question 16

Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. In the storing derived data physical database design technique, the best place to store the derived data from Table B is ____.

Accepted Answer

The storing derived data physical database design technique suggests storing the derived data in a new column in the table on the "one side" of the relationship (Table A), to avoid redundancy and ensure data consistency. Storing the derived data in a new column in Table B would violate normalization rules and create redundancy. Creating a new record type in either Table A or Table B is not necessary or efficient for storing derived data.

Question 17

Consider Table A on the "one side" of a one-to-many relationship and Table B on the "many side" of the relationship. The "repeating groups" in Table B may be considered for merging into the related records of Table A if ____.

Accepted Answer

Repeating groups in Table B should be considered for merging into the related records of Table A if there is a small number of occurrences of the repeating groups for each record of Table A. This will eliminate redundancy and improve the efficiency of the database. Option A is incorrect because a large number of occurrences of the repeating groups does not necessarily mean they should be merged into Table A. Option C is also incorrect because the presence of indexes does not determine whether merging is necessary or not. Option D is not entirely correct as only option B is applicable. Option E is not applicable as well.

Question 18

The creating a new primary key physical database design technique is designed to ____.

Accepted Answer

The creating a new primary key physical database design technique is designed to replace clumsy keys that have a large number of attributes, which can improve performance and simplify the design. It is not directly related to reducing the number of joins or indexes, although these may be indirectly affected by the new primary key. So, option C is the best choice.

Question 19

In the adding new tables physical database design technique ____.

Accepted Answer

All of the options describe valid techniques in the physical database design process for adding new tables. These techniques aim to improve performance by creating subsets or copies of tables and accepting some level of data redundancy.

Question 20

A "fixed" or "hard" disk drive operates with removable diskettes.

Accepted Answer

A fixed or hard disk drive does not operate with removable diskettes. Removable diskettes are mainly used with floppy disk drives.

Quiz 8: Physical Database Design