Chapter 5 - Intro to Databases

Question 1

What is transactional information and what kind of database is it stored in?

Answer 1

Transactional information is data generated by business processes (ie. date, time, customer ID, location of an ATM withdrawal) .

It is kept in an operational database.

Question 2

What is analytical information and what kind of database is it stored in?

Answer 2

It is data that can be used to help the company strategically.

It is stored in a data warehouse so their analysis of it doesn’t affect the functionality of the operational database.

Question 3

What is information granularity?

Answer 3

The scale or level of detail in a set of data.

Question 4

What does it mean if data has a fine granularity?

Answer 4

The data is in its raw form

Question 5

What does it mean if data has summary granularity?

Answer 5

It is the second level of granularity, it summarizes transactional information and turns it analytical.

Question 6

What does it mean if data has course granularity?

Answer 6

The data has been aggregated super duper far. (IE the entire company’s weekly sales)

Question 7

What are the five elements of high-quality information?

Answer 7

TUCAC (to remember)

timeliness
uniqueness
completeness
accuracy
consistency

Question 8

Tell me about timeliness. What is it? What does it help measure?

Answer 8

It helps measure data quality.

It refers to how “fresh” and “relevant” the data is.

Question 9

Tell me about accuracy. What is it? What does it help measure?

Answer 9

It helps measure data quality.

Is the information correct? Is it the right information? Is it misspelled?

Question 10

Tell me about completeness. What is it? What does it help measure?

Answer 10

It helps measure data quality.

Checking whether all or part of a value is missing. Are all the digits there? Is there a blank field?

Question 11

Tell me about uniqueness. What is it? What does it help measure?

Answer 11

It helps measure data quality.

Is each piece of data unique? Or are there duplicates?

Question 12

Tell me about consistency. What is it? What does it help measure?

Answer 12

It helps measure data quality.

Caused by techincal bugs. Do the numbers add up? Was the algorithm written correctly?

Question 13

Should we strive for perfect information all the time?

Answer 13

No! Satisficing is the practice of making decisions without perfect information because the cost may exceed the value of perfect information.

Question 14

Is it more important to know the quality of your information or have perfect information?

Answer 14

Know the quality of your information so you can make informed decisions

Question 15

What is database normalization?

Answer 15

Separating data into a set of related tables

Question 16

What is primary key?

Answer 16

In a normalized relational database, it is the unique identifier of every record in the database.

Question 17

What is a semantic key?

Answer 17

A primary key that is simply data we already had to record (Ie. social security number. it is completely unique, therefore it can be used as a primary key)

Question 18

What is an artificial key?

Answer 18

A field that we had to create for the sole purpose of creating a primary key

Question 19

What is a database field?

Answer 19

A column

Question 20

What is a record in a database?

Answer 20

Row

Question 21

What is the job of a foreign key?

Answer 21

To match up to a “key” (like on a map. that’s called the primary key)