Chapter 5 - Intro to Databases Flashcards
What is transactional information and what kind of database is it stored in?
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.
What is analytical information and what kind of database is it stored in?
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.
What is information granularity?
The scale or level of detail in a set of data.
What does it mean if data has a fine granularity?
The data is in its raw form
What does it mean if data has summary granularity?
It is the second level of granularity, it summarizes transactional information and turns it analytical.
What does it mean if data has course granularity?
The data has been aggregated super duper far. (IE the entire company’s weekly sales)
What are the five elements of high-quality information?
TUCAC (to remember)
timeliness
uniqueness
completeness
accuracy
consistency
Tell me about timeliness. What is it? What does it help measure?
It helps measure data quality.
It refers to how “fresh” and “relevant” the data is.
Tell me about accuracy. What is it? What does it help measure?
It helps measure data quality.
Is the information correct? Is it the right information? Is it misspelled?
Tell me about completeness. What is it? What does it help measure?
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?
Tell me about uniqueness. What is it? What does it help measure?
It helps measure data quality.
Is each piece of data unique? Or are there duplicates?
Tell me about consistency. What is it? What does it help measure?
It helps measure data quality.
Caused by techincal bugs. Do the numbers add up? Was the algorithm written correctly?
Should we strive for perfect information all the time?
No! Satisficing is the practice of making decisions without perfect information because the cost may exceed the value of perfect information.
Is it more important to know the quality of your information or have perfect information?
Know the quality of your information so you can make informed decisions
What is database normalization?
Separating data into a set of related tables
What is primary key?
In a normalized relational database, it is the unique identifier of every record in the database.
What is a semantic key?
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)
What is an artificial key?
A field that we had to create for the sole purpose of creating a primary key
What is a database field?
A column
What is a record in a database?
Row
What is the job of a foreign key?
To match up to a “key” (like on a map. that’s called the primary key)
