Comp 3 | Quiz 2 | Mkm 2-5

Explanation
Physical independence refers to the ability to make changes in the physical schema of a database without needing to modify the logical schema. In other words, it allows for modifications in the way data is stored, such as adding or removing tables, without affecting the way the data is accessed or understood by users or applications. This ensures that the logical schema remains unchanged and minimizes the impact of physical changes on the overall database structure.

Explanation
By specifying integrity constraints, we can ensure the accuracy and consistency of data in a database. These constraints define rules and restrictions that the data must follow, such as primary key constraints, foreign key constraints, and check constraints. By enforcing these constraints, we can prevent invalid or inconsistent data from being entered into the database, thus maintaining data integrity. Therefore, the statement "We can maintain data integrity by specifying integrity constraints" is true.

Explanation
Reduction of redundancy is the most significant advantage of using a DBMS because it eliminates the need for storing duplicate data in multiple places. By centralizing data storage and using relationships between tables, a DBMS ensures that data is stored only once, reducing the storage space required and improving data consistency. This also simplifies data updates and maintenance, as changes only need to be made in one place. Additionally, it improves data integrity by minimizing the risk of inconsistent or conflicting data.

Explanation
Redundancy is not included in the given options. Physical independence refers to the ability of a system or component to perform its functions without being affected by physical changes or failures in other parts. Logical independence refers to the ability of a system or component to perform its functions without being affected by logical changes or failures in other parts. Redundancy, on the other hand, refers to the inclusion of extra components or systems that are not necessary for normal operation but are available in case of failures or emergencies.

Explanation
Logical Data Independence refers to the ability to modify the logical schema of a database without affecting the application programs that access the data. It allows for changes in the structure and organization of the data without requiring changes to the programs that use the data. The other options, Reduction of Redundancy, Sharing of Data, and Data Integrity, are all important aspects of database management and are typically included in the design and implementation of a database system. Therefore, Logical Data Independence is not included in this list of database concepts.

Explanation
The functions of a Database Administrator include defining the schema, which refers to the organization and structure of the database, as well as the architecture of the three levels of data abstraction, which are the conceptual, logical, and physical levels. The DBA is also responsible for modifying the schema when necessary. Additionally, the DBA defines the storage structure and access methods for the data, such as sequential, indexed, or direct. Lastly, the DBA creates new user IDs, passwords, and access permissions for each user, determining what they can or cannot do within the database.

Explanation
The statement "There are no disadvantages in using DBMS" is false. While DBMS (Database Management System) offers numerous advantages such as data security, data integrity, and efficient data management, it also has certain disadvantages. Some of these include high initial setup costs, complexity in implementation and maintenance, potential for data breaches or data loss, and dependency on the DBMS vendor. Therefore, it is incorrect to claim that there are no disadvantages in using DBMS.

Explanation
The correct answer is "Database Administrator" because DBA stands for Database Administrator. A Database Administrator is responsible for managing and maintaining a company's database systems, ensuring their security, performance, and availability. They handle tasks such as database design, installation, configuration, backup and recovery, and user management. A DBA plays a crucial role in ensuring the smooth operation of a database system and optimizing its performance.

Explanation
Logical data independence refers to the ability to make changes to the logical schema of a database without affecting the external schema or the application programs that access the data. This means that any modifications or updates made to the logical schema, such as adding or deleting tables or modifying relationships between tables, will not require changes to be made to the external schema. This allows for flexibility and ease of maintenance, as it reduces the impact of changes on the applications that rely on the database.

Explanation
Creating a backup and recovery policy is essential because it helps protect data and ensure business continuity. Without a backup and recovery policy, organizations are at risk of losing important data in case of hardware failures, natural disasters, or cyber attacks. A backup and recovery policy outlines procedures for regularly backing up data, storing backups securely, and restoring data in case of any incidents. This helps minimize downtime and potential damage to the organization's operations. Therefore, the correct answer is False.