Database Types

Question 1

What are the 3 open source relational databases mentioned in the book?

Answer 1

MySQL,
MariaDB
PostgreSQL

Question 2

Acording to the book, what are the three distinct differences about a non-relational database compared to a relational one?

Answer 2

1) They don’t have a predefined structure based on tabular data
2) Data validation happens in code, as opposed to being done in the DB
3) Data types are absent

while they aren’t tabular, they still can store structured data! Data-types aren’t entirely excluded, they’re just not rigidly enforced and can be defined by the user.

Question 3

Which of the below non-relational database type stores data in the most simplest of the non-relational types and is suited for applications that need fast and scalable access?

Key-Value
Document
Column-Family
Graph

Answer 3

Key-Value.

Question 4

Match the key value type to the database. Note, the same structure choice can apply to more than one database

1) can be structured, semi-structured and unstructured
2) structured only
3) structured or semi-structured

key-value
document
column-family
graph*

Answer 4

1) can be structured, semi-structured and unstructured - document
2) can be structured, semi-structured and unstructured - column-family
3) can be structured, semi-structured and unstructured - key-value
4) can be structured, semi-structured and unstructured - graph

Yes! They’re all the same!

*graph databases don’t use key value pairs but the properties is akin to columns in a relational database and these can contain the structures above.

Question 5

What is meant by globally unique keys in reference to key-value databases?

Answer 5

The keys are not just unique to the table but unique across different databases or servers.

Question 6

Is similar to a key-value database but instead the value must conform to a strict format, rather than have no structural limits

Answer 6

Document database

format structure not to be confused with the structure of the data!

Question 7

can search using both the key and within the value itself

Answer 7

Document database

because the value has a known structure

Question 8

1) It uses xxx-xxxxx pairs to store data
2) xxxxxxx that share similar types of data are grouped into what’s called a xxxxxx xxxxx
3) xxxx are linked to one or more xxxxxx xxxxxxx
4) Each xxxxxx within a xxxxxx xxxxx is stored separately in their own partition

Answer 8

1) It uses KEY-VALUE pairs to store data
2) COLUMNS that share similar types of data are grouped into what’s called a COLUMN FAMILY
3) KEYS are linked to one or more COLUMN FAMILIES
4) Each COLUMN within a COLUMN FAMILY is stored separately in their own partition

Question 9

Which of the four database types below would you choose if you need to store massive data sets with lots of attributes and relationships that needs to scale?

Key-value
Column-family
Graph
Document

Answer 9

Column-family

Question 10

You need to store and retrieve simple data quickly that doesn’t have a lot of structure, which of the two non-relational databases would you choose?
Key-value or Column-family

Answer 10

Key-value

Question 11

a key value pair is a way of storing and retrieving ____?

Answer 11

Key-value pair is a way of storing and retrieving data

Question 12

What kind of database best supports complex data like social networks, fraud detection and recommendation systems?

Answer 12

Graph databases

Question 13

a column-family database stores data in columns, TRUE or FALSE

Answer 13

No, in rows.

Question 14

which non-relational databases tend to use programming languages to query the data as opposed to using a query language?

Answer 14

key-value and document databases

Question 15

Which database type would you pick if you needed to handle many simultaneous requests at speed and is easily scalable?

Answer 15

key-value

Question 16

key-value databases tend to be associated with ____ systems, whereas column family databases tend to be associated with ____ systems

Answer 16

1) key-value databases tend to be associated with OLTP systems
2) column family databases tend to be associated with OLAP systems

Question 17

which kind of database stores data in field-value pairs?

Answer 17

Document database

Question 18

If you are working with data that may change frequently over time through development, which database type would be best?

key-value database
column-family database
document database

Answer 18

Document database

Question 19

can query within a _____ in a document database, whereas only the _______ can be queried in a key-value database

Answer 19

can search within a VALUE in a document database, whereas only the KEY can be queried in a key-value database

this is due to the value part requiring specific strucutre

Question 20

Which database type stores data in self-contained objects in a specific structured format?

Answer 20

Document databases

Question 21

Flexibility and agility is your priority, which database would you pick?

key-value
column-family
document

Answer 21

document database

Question 22

which database type uses traversal algorithms to query data?

document
column-family
key-value
graph

Answer 22

Graph databases

Question 23

Link the statements with the database types

1) efficient at handling structured data
2) optimized for read-heavy OLAP systems
3) Optimized for write-heavy, semi structured and unstructured
4) suited for OLTP systems storing frequently accessed data that needs to be retrieved quickly
5) Optimized for time-series data

Relational database
column-family database
document database
key-value

Answer 23

1) efficient at handling structured data / Relational database

2) optimized for read-heavy OLAP systems / column-family database

3) Optimized for write-heavy, semi structured and unstructured / document database

4) suited for OLTP systems storing frequently accessed data that needs to be retrieved quickly / key-value
5) Optimized for time-series data / column-family database

Question 24

Which non-relational database types are more often used in OLAP systems?

Answer 24

Column-family and Graph databases

they of course can be used for OLTP but much less so than relational databases.

Question 25

Which database types are more often used in OLTP database?
Which can be an exception?

Answer 25

Key-Value
Document
Tabular

Document can be an exception.

Question 26

….are a way of ensuring data integrity and relationships between tables

Answer 26

Primary keys and foreign keys