Pt2520 Unit 6
Answers to review questions:
1. Define each of the following terms:
a. Data: Raw information that has not been processed
b. Field: A place where data is entered.
c. Record: A collection of the related information.
d. File: A collection of the related records.
2. What is data redundancy, and which characteristics of the file system can lead to it?
Data redundancy in a database occurs when same data is stored in different tables unnecessarily. A modification to a single piece of data requires change for all the copies. Use of flat file database designs and spreadsheets can lead to data redundancy.
3. What is data independence, and why is it lacking in file systems?
Data independence, it exists when we were able to change the database structure or characteristics without affecting the …show more content…
What is a DBMS, and what are its functions?
i) DBMS, a collection of programs that are stored, managed and simultaneously given controlled access to the end users to create, modify and delete. ii) Functions of a DBMS:
(1) Views
(2) Indexing
(3) Concurrency
(4) Security
(5) Integrity
(6) Backup and recovery
5. What is structural independence, and why is it important?
It occurs when we can change the file structure without affecting the accessibility of the data.
It is important because any change to a file requires the change to the original file making it inaccessible to other applications/programs which further leads to a bad structure.
6. Explain the differences among data, information, and a database?
Data: unprocessed facts collected together for analysis.
Information: Processed data from the raw facts.
Database: A database is where the information is stored in tables.
7. What is the role of a DBMS, and what are its advantages? What are its disadvantages?
The role of DBMS is to manage and store the databases.
Advantages:
a. Lower data redundancy
b. Data independence
c. Allows different view of data regardless of which user is accessing it.
d. Better security
1. Define each of the following terms:
a. Data: Raw information that has not been processed
b. Field: A place where data is entered.
c. Record: A collection of the related information.
d. File: A collection of the related records.
2. What is data redundancy, and which characteristics of the file system can lead to it?
Data redundancy in a database occurs when same data is stored in different tables unnecessarily. A modification to a single piece of data requires change for all the copies. Use of flat file database designs and spreadsheets can lead to data redundancy.
3. What is data independence, and why is it lacking in file systems?
Data independence, it exists when we were able to change the database structure or characteristics without affecting the …show more content…
What is a DBMS, and what are its functions?
i) DBMS, a collection of programs that are stored, managed and simultaneously given controlled access to the end users to create, modify and delete. ii) Functions of a DBMS:
(1) Views
(2) Indexing
(3) Concurrency
(4) Security
(5) Integrity
(6) Backup and recovery
5. What is structural independence, and why is it important?
It occurs when we can change the file structure without affecting the accessibility of the data.
It is important because any change to a file requires the change to the original file making it inaccessible to other applications/programs which further leads to a bad structure.
6. Explain the differences among data, information, and a database?
Data: unprocessed facts collected together for analysis.
Information: Processed data from the raw facts.
Database: A database is where the information is stored in tables.
7. What is the role of a DBMS, and what are its advantages? What are its disadvantages?
The role of DBMS is to manage and store the databases.
Advantages:
a. Lower data redundancy
b. Data independence
c. Allows different view of data regardless of which user is accessing it.
d. Better security