Week 1: ER Diagrams

Question 1

What is data?

Answer 1

Known facts that can be recorded and have an implicit meaning.

Question 2

What is a database

Answer 2

A collection of related data

Question 3

What is a mini-world?

Answer 3

A database is a model of a mini world. Some part of the real world about which data is stored in a database. E.g. medical office, a retail business, a library are all mini worlds

Question 4

What is a DBMS

Answer 4

A software package/system to facilitate the creation and maintenance of a computerized database.

Question 5

What is a Database system

Answer 5

Question 6

What is a flat file?

Answer 6

a .txt or an ASCII file

Question 7

What is a record/instance?

Answer 7

One row of a flate file

Question 8

What is a DBMS and what are its advantages over flate file system

Answer 8

Question 9

What is a database administrator? What are their responsibilities?

Answer 9

Question 10

What is a Database Designer? What are their responsibilities?

Answer 10

Question 11

What are system analysis and application programmers? What are their responsibilities?

Answer 11

Question 12

What is an end user? Responsibilities?

Answer 12

Question 13

What is a database schema?

Answer 13

Question 14

What is a database instance?

Question 15

What is a database state/snapshot?

Answer 15

Question 16

What is the 3 schema architecture?

Answer 16

Question 17

What is the difference between logical data independence and physical data independence?

Answer 17

Question 18

1. When starting a project, you should always start with …
2. Narrow your ___ as much as possible and figure out what data you need to store/save by…

Answer 18

Question 19

What model do we use to represent a database before creating it? Who made it?

Answer 19

Question 20

When designing a DB, pay attention to..

Answer 20

NOUNS

Question 21

What are the following:

Entity

Attribute

Value

Composite Attribute vs. Atomic attribute

Single-valued attribute vs. multi-valued attribute

Derived attribute vs stored attribute

Answer 21

Question 22

What are the following:

Entity type

Entity

Entity set

Key, uniqueness

Value Sets

Answer 22

Question 23

How are the following represented in ER diagrams?

Entity type

Attribute

Key attribute

Multi-valued attribute

Composite attribute

Derived attribute

Answer 23

Question 24

What are the following:

Relationship

Relationship set

A relationship Type R

Answer 24

Question 25

Example of binary, ternary, and unary relationships

Answer 25

Question 26

What are the following Recursive relationship Attributes on relationships Cardinality ratio

Answer 26

Question 27

How are the following represented in ER diagrams? Relationship type Relationship attribute Cardinality

Answer 27

Question 28

What is participation constraint? Total participation? Partial participation? (min,max) notation?

Answer 28

Question 29

How are relationship participations and (min,max) notation represented in ER diagrams?

Answer 29

Question 30

Question 31

What is a weak entity? How are they represented in ER diagrams?

Answer 31

Question 32

In ER diagrams what is the naming convention?

Answer 32

Question 33

How are entities represented in crow's feet notation?

Answer 33

Question 34

How are relationships represented in crows feet notation?

Answer 34