data 2

Question 1

What is the main responsibility of data analysts?

Answer 1

To find out the answers or more insights from the data and creating dashboards with appropriate visualizations.

Question 2

What does a Data Engineer do?

Answer 2

Responsible for designing, building, and maintaining the infrastructure to store data. Needs strong technical background, ability to create and integrate APIs, and understand data pipelining and performance optimization.

Question 3

What is the primary responsibility of data scientists?

Answer 3

To find patterns in the data and answer questions about the future.

Question 4

Which technology is used to fetch, process, and display XML data from server to client?

Answer 4

Ajax

Question 5

What is metadata?

Answer 5

A database definition or descriptive information stored by the DBMS in the form of a database catalog or dictionary.

Question 6

What are the three main concepts of the ER model?

Answer 6

• Entities * Attributes * Relationships

Question 7

What shape is used to display a relationship type in ER diagrams?

Answer 7

Diamond

Question 8

What are the types of cardinality ratio/constraints on relationships?

Answer 8

• One-to-one (1:1) * One-to-many (1:N) * Many-to-one (N:1) * Many-to-many (M:N)

Question 9

What is a weak entity?

Answer 9

An entity that does not have a key attribute and is identification dependent on another entity type.

Question 10

What are relationship types of degree 2 called?

Answer 10

Binary

Question 11

What are relationship types of degree 3 called?

Answer 11

Ternary

Question 12

What is specialization in database design?

Answer 12

The process of defining a set of subclasses of a superclass.

Question 13

What is generalization in database design?

Answer 13

The process where several classes with common features are generalized into a superclass.

Question 14

What are the two basic constraints that can apply to a specialization/generalization?

Answer 14

• Disjointness Constraint * Completeness Constraint

Question 15

True or False: XML is a universal format for the exchange of data.

Answer 15

True

Question 16

True or False: One of the main disadvantages of XML is that its bulky syntax and structure make files large and can decrease performance.

Answer 16

True

Question 17

True or False: XML uses specific tags to design an XML file.

Answer 17

False

Question 18

True or False: Browsers can interpret and parse XML data into a set of objects.

Answer 18

True

Question 19

What does the term ‘data abstraction’ refer to?

Answer 19

Suppression of details of data organization and storage, highlighting essential features for improved understanding of data.

Question 20

What is a database schema?

Answer 20

Description of a database.

Question 21

What does a database state or snapshot represent?

Answer 21

Data in database at a particular moment in time.

Question 22

What is an entity in the context of databases?

Answer 22

A specific thing or object in the mini-world that is represented in the database.

Question 23

What are attributes in a database?

Answer 23

Properties used to describe an entity.

Question 24

What are composite attributes?

Answer 24

Attributes that may be composed of several components.

Question 25

What is a recursive relationship type?

Answer 25

A relationship type between the same participating entity type in distinct roles.

Question 26

What does the disjointness constraint specify?

Answer 26

The subclasses of the specialization must be disjoint: an entity can be a member of at most one of the subclasses.

Question 27

What differentiates composite attributes from multi-valued attributes?

Answer 27

Composite attributes consist of several components, while multi-valued attributes allow an entity to have multiple values.

Question 28

What are total and partial completeness constraints?

Answer 28

* Total: Every entity in the superclass must be a member of some subclass. * Partial: An entity may not belong to any of the subclasses.

Question 29

What are attributes of relationship types?

Answer 29

Attributes that can describe the relationship, such as HoursPerWeek in WORKS_ON.

Question 30

What is hierarchy and lattice inheritance?

Answer 30

Hierarchy allows each subclass to have only one superclass, while lattice allows a subclass to have multiple superclasses.

Question 31

What characterizes centralized DBMS architecture?

Answer 31

All DBMS functionality, application program execution, and user interface processing are carried out on one machine.

Question 32

What defines client/server architectures?

Answer 32

Server handles query and transaction functionality, while the client handles user interface programs.

Question 33

What is a requirement for the COMPANY database schema regarding departments?

Answer 33

Each department has a name, number, and an employee who manages the department.

Question 34

What information must be stored for each employee in the COMPANY database?

Answer 34

* Social security number * Address * Salary * Sex * Birthdate

Question 35

What must the database keep track of regarding employees and projects?

Answer 35

The number of hours per week that an employee currently works on each project.

Question 36

What is required to track for dependents in the COMPANY database?

Answer 36

Name, sex, birthdate, and relationship to the employee.