Week 1

Question 1

What data model is often use in the real world?

Answer 1

relational data model

Question 2

What falls under the umbrella of data management?

Answer 2

collection, extraction, cleaning, transformation

Question 3

What falls under the umbrella of data analysis?

Answer 3

querying, modeling, visualizations

Question 4

What is a database?

Answer 4

a collection of files storing related data

Question 5

What does DBMS stand for?

Answer 5

database management system

Question 6

What is a database management system?

Answer 6

a big program written by someone else that allows us to efficiently manage a large database that will persist over time

Question 7

What are some examples of DBMSs?

Answer 7

MSSMS, SQLite, PostgreSQL

Question 8

What must data be in order for it to outlive the application?

Answer 8

it must be persistent

Question 9

What is a DBMS implementor?

Answer 9

builds the database management systems

Question 10

What is a DB designer?

Answer 10

establishes schema

Question 11

What is a DB administrator?

Answer 11

loads data, tunes system, and keeps the whole thing running

Question 12

What is a Data Engineer?

Answer 12

builds and maintains data pipelines, infrastructure, and storage

Question 13

What is a DB application developer?

Answer 13

writes programs that query and modify data

Question 14

What does a Data Analyst do?

Answer 14

data mining/machine learning

Question 15

What is a data model?

Answer 15

conceptual/mathematical way for describing the data

Question 16

How are semi-structured data models represented?

Answer 16

as trees

Question 17

How are key-value pair models represented?

Answer 17

by NoSQL systems

Question 18

How are relational data models represented?

Answer 18

as relations

Question 19

What is an instance?

Answer 19

the actual data

Question 20

What is a schema?

Answer 20

describes what data is being stored

Question 21

What is a query language?

Answer 21

how we retrieve and manipulate data

Question 22

What is another name for relations?

Answer 22

tables

Question 23

What is a relation, mathematically?

Answer 23

a set of tuples

Question 24

Order of the rows is __________.

Answer 24

unspecified

Question 25

What are two other names for columns?

Answer 25

attributes and/or fields

Question 26

What is true about each attribute in a relational data model?

Answer 26

each one has a type

Question 27

What is unique what about attribute types in relational data models?

Answer 27

they are statically and strictly enforced

Question 28

What is another way we will commonly see "# of attributes"?

Answer 28

"degree" of a relation

Question 29

What is a key?

Answer 29

one or more attributes that uniquely identify a record

Question 30

While a table may have multiple keys, it can only have one...

Answer 30

primary key

Question 31

What is a foreign key?

Answer 31

it is an attribute(s) whose value is a key of a record in some other relation

Question 32

What is another word for foreign key?

Answer 32

semantic pointer

Question 33

How can we usually tell if an attribute is a key?

Answer 33

it will be underlined

Question 34

What does SQL stand for?

Answer 34

Structured Query Language

Question 35

Tables are NOT ________.

Answer 35

ordered

Question 36

What does it mean when we say that tables are flat?

Answer 36

they have no nested attributes

Question 37

What is physical data independence?

Answer 37

tables do not prescribe how they are implemented/stored on disk

Question 38

What is row major?

Answer 38

an array of objects

Question 39

What is column major?

Answer 39

one array per attribute

Question 40

What do we know about a relation if it is in first normal form?

Answer 40

it is flat

Question 41

What is another way we say rows?

Answer 41

records

Question 42

What are relational data models usually used for?

Answer 42

transaction systems and business intelligence

Question 43

What is are semistructured data models used for?

Answer 43

content management, web APIs, IoT

Question 44

When should we used a semistructured data model?

Answer 44

when structure evolves over time

Question 45

When do we want to use key-value data models?

Answer 45

caching, real-time applications

Question 46

What does a key-value data model prioritize?

Answer 46

simplicity and performance for lookups

Question 47

When do we use graph data models?

Answer 47

social networks, recommendation engines, fraud detection, network analysis

Question 48

What are graph data models?

Answer 48

data is represented as nodes and edges; ideal for modeling and querying relationships between entities

Question 49

What are some graph data model names?

Answer 49

neo4j, amazon neptune

Question 50

What is an array/matrix data model?

Answer 50

data is represented as multi-dimensional arrays or matrices, suitable for numerical and scientific computations

Question 51

What are some use cases for array/matrix data models?

Answer 51

scientific computing, high-dimensional data, storing and processing training data for models

Question 52

What are dataframes?

Answer 52

data is structured as a two-dimensional tabular format and used for in-memory computations

Question 53

What are some examples of dataframes?

Answer 53

apache spark, pandas

Question 54

What are dataframes used for?

Answer 54

EDA, big data analytics, machine learning pipelines, business analytics

Question 55

What is a relational schema?

Answer 55

describes the relation's name, attribute name and their domain

Question 56

What is another name for domain?

Answer 56

metadata

Question 57

What are integrity constraints?

Answer 57

a condition specified on a database schema and restricts the data that can be stored in an instance

Question 58

What is a key constraint?

Answer 58

a statement that a minimal subsets of attributes uniquely identify a tuple

Question 59

What is a foreign key constraint?

Answer 59

if one of the relations is modified then the other one should be checked for consistency

Question 60

Tables are _______ collections of data.

Answer 60

unordered

Question 61

The ____________ has no impact on the functionality of the database.

Answer 61

order of rows