The Relational Database

Question 1

What is a database

Answer 1

A database is an organized collection of data used for the purpose of modeling some type of organization or organizational process

Question 2

What are the two kinds of databases

Answer 2

The two kinds of databases are operational databases and analytical databases

Question 3

What is OLTP

Answer 3

OLTP means online transaction processing

Question 4

What kind of databases are used in OLTP

Answer 4

Operational databases are used in online transaction processing

Question 5

What is an operational database for?

Answer 5

operational database is dynamic. It changes constantly. It always reflects up to the minute information. Used when there is need to collect, modify, and maintain data on a daily basis

Question 6

What is OLAP

Answer 6

OLAP is online analytical processing

Question 7

What is OLAP used for?

Answer 7

When there is a need to store and track historical and time-dependent data to track trends, view statistical data over time, make tactical or strategic business projections.

Question 8

What were early database models?

Answer 8

Hierarchical database and network database were early database models

Question 9

What is a hierarchical database

Answer 9

A hierarchical database is an inverted tree branches flowing from the route

Question 10

What is the parent child relationship in a hierarchical database

Answer 10

A parent table can be associated with one or more child tables but a single child table can be associated with only one parent table

Question 11

What is one problem with a hierarchical database?

Answer 11

Users must be very familiar with the structure of the database as users must access data by starting at the route table and working down through the tree to the target data

Question 12

What are two benefits of a hierarchical database

Answer 12

1. the user can retrieve data very quickly because there are explicit links between the table structures
2. the referential integrity is built in and automatically enforced the child must be linked automatically to a parent and if the parent is deleted the child will also be deleted

Question 13

What is another problem with hierarchical databases?

Answer 13

Every item must have a parent, rules cannot be bent without breaking them, every piece of data must be related to another piece of data, it cannot support complex relationships

Question 14

What is redundant data

Answer 14

Redundant data is when data is entered into two places unnecessarily

Question 15

What is a network database model

Answer 15

network database model is represented in terms of nodes and set structures

Question 16

What are nodes?

Answer 16

Nodes represent a collection of records

Question 17

What are set structures?

Answer 17

Set structures establishes and represents a relationship and the network database

Question 18

How is set structure different than parent child relationships

Answer 18

Node of owner and node member, transparent instruction relating a pair of nodes together, supports one to many relationship,

Question 19

How does the owner member structure work

Answer 19

Owner can have many members, but a member can have only one owner, a member cannot exist without a relationship to an owner node

Question 20

What are set structures

Answer 20

Set structures are the way that data is related to each other, you cannot change a set structure without affecting the application program that use the structure to navigate the data, if you change a set structure, you also change all references from within the application to that structure

Question 21

Why is a network database better than a hierarchical database?

Answer 21

Fast data access, users can create queries that are more complex, however users must be very familiar with the structure of the database and its set structures

Question 22

What did Codd believe could be solved in databases by using mathematics?

Answer 22

Data redundancy, week data integrity, database structures over dependence on physical implementation

Question 23

Relational database model is based on what kind of math?

Answer 23

Relational database model is based on set theory and first order predicate logic

Question 24

What is a tuple?

Answer 24

A TU PL E is a record or attribute Or field in other words a part of a table

Question 25

Does the order of the table matter

Answer 25

No the order of the table is imaterial

Question 26

Why is a relational database an improvement from previous databases

Answer 26

users do not need to know the physical location of a record in order to retrieve its data

Question 27

What are the categories of relationships in a relational database

Answer 27

121, one too many, and many to many

Question 28

What does the user of a relational database need to understand

Answer 28

The user needs to be familiar with the relationships among the tables in the database then he can access data and an almost unlimited number of ways

Question 29

Do tables need to be related in a relational database

Answer 29

No they do not need to be directly related

Question 30

What is SQL

Answer 30

Structured query language

Question 31

What is the purpose of structured query language

Answer 31

Structured query language is the process for accessing a relational database. Understanding structured query language will help you to build your queries and understand and troubleshoot your database

Question 32

What are the four advantages of relational databases?

Answer 32

Built in multilevel integrity, logical and physical data independence From database applications, guaranteed data consistency and accuracy, easy data retrieval

Question 33

What is multi level integrity

Answer 33

Table level: cannot duplicate records, detect missing key values. Relationship: ensure relationship between a pair of tables is valid. Business: accurate data in terms of the business

Question 34

What is logical and physical data independence from database applications?

Answer 34

Changing the data will not change the software or the applications that use the data

Question 35

What is guaranteed data consistency and accuracy?

Answer 35

The integrity of each level creates consistency and accuracy

Question 36

What is easy data retrieval

Answer 36

Being able to retrieve data from a particular table or any number of related tables easily

Question 37

Why did relational databases run slowly and how has technology improves

Answer 37

Hardware was unable to keep up with the speed required for databases to reach their full potential but now processing power of computers is cheap and has become an insignificant issue

Question 38

What is a relational database management system RDBMS

Answer 38

RDBMS is a software application program you use to create, maintain, modify, and manipulate a relational database

Question 39

What is the client server model of databases

Answer 39

Data resides on server computer and clients interact with the data through an application that resides on their own computers or database client machine. This allows for data integrity and data security on the database server. The client can use the data without affecting the data integrity or security

Question 40

What is object oriented model

Answer 40

No longer is there a clear separation between the database software and the application programming software. Object-oriented database model has no specific theoretical foundation. There is no cohesive definition

Question 41

What is OMG?

Answer 41

OMG: object management group a nonprofit international group that addresses the issues of object standards. It is not a standards body such as the American national standards Institute. It is an advisory and certification group

Question 42

How is OM different than a relational database

Answer 42

OMG allows video clips photographs MP3s to be included in a database

Question 43

What is a data warehouse?

Answer 43

A data warehouse allows organizations to access data stored in any number of nonrelational databases