Lecture #1 Review

Question 1

Give 5 disadvantages of using a file-based system.

Answer 1

• Data Redundancy
• Data Isolation
• Integrity problems
• Security Problems
• Concurrency access

Question 2

Describe Data Redundancy.

Answer 2

This occurs in a database when a field needs to be updated in more than one table.

Question 3

Describe a File System.

Answer 3

A file system is a method and data structure that the operating system uses to control how data is stored and retrieved on a storage device, such as a hard drive, SSD, or USB flash drive.
- Without a file system, data placed in a storage
medium would be one large block of data with
no way to distinguish or identify the pieces of
information.

Question 4

Describe Data Isolation

Answer 4

It ensures that transactions are executed in a way that they do not interfere with each other, maintaining the consistency and integrity of the database.

Question 5

Describe Integrity Problems

Answer 5

Consists of maintenance and assurance that the data in a database is correct and consistent.

Question 6

Describe Security Problems.

Answer 6

Problems that occur within a file based system because of constraints accessing privileges.

Question 7

Describe Concurrency Access.

Answer 7

Concurrency is the ability of the database to allow multiple users access to the same
record without adversely affecting transaction processing. A file-based system must
manage, or prevent, concurrency by the application programs. Typically, in a filebased system, when an application opens a file, that file is locked. This means that
no one else has access to the file at the same time.

Question 8

What is Data?

Answer 8

Factual Information such as measurements or statistics about objects and concepts.

Question 9

Give examples of where Data can be stored .

Answer 9

• Filing cabinets
• Spreadsheets
• Folders
• Ledgers
• Lists
• Piles of papers on your desk

Question 10

What is a Database?

Answer 10

A shared collection of related data used to support the activities of a particular organization.

Question 11

Characteristics & Benefits of a Database.

Answer 11

• Self Describing
• Insulations between program & data
• Support for multiple views of data
• Sharing of data & Multiuser Systems
• Control of data redundancy
• Data Sharing

Question 12

Provide a List of Data Models

Answer 12

• Relational Data Model
• Hierarchical Data Model
• Network Data Model

Question 13

List 4 Distribution Systems

Answer 13

• Centralized Systems
• Distributed Database
• Homogeneous Distributed Systems
• Heterogeneous Distributed Systems