Exam Questions and CORRECT Answers
True or false, sources of dat are becoming larger and more diverse - CORRECT
ANSWER -True, Billions or even trillions of data sources
What is the goal of data processing? - CORRECT ANSWER -To extract data that is useful
Why is the volume of data that is available so large? - CORRECT ANSWER -Increasing
number of data sources (social media, wearable tech, sensors, cameras, etc), formats, and data
points
How much data is possibly generated in a day? - CORRECT ANSWER -A petabyte (1
million GB)
What is scalable data processing? - CORRECT ANSWER -Allows database processing
systems to cope with the volume, velocity, and variety aspects that big data brings into the
system
What are the different types of data processing systems? - CORRECT ANSWER -
Relational DBMS, NoSQL Graph/Document Key Value Stores, and Hadoop/Spark
What are the characteristics of a Relational DBMS? - CORRECT ANSWER -Operational
workload, presents entities and objects in the world using tables and relations between tables
What are the characteristics of a NoSQL Graph, Document, Key Value Stores? - CORRECT
ANSWER -Unstructured data, highly available systems. Runs queries that extract
knowledge from the data.
What are the characteristics of Hadoop/Spark? - CORRECT ANSWER -Not operational,
for analytics over massive scale data
, What is a database? - CORRECT ANSWER -A very large, integrated collection of data
that models real world enterprises using entities and relationships between those entities
What are the three goals of a DBMS? - CORRECT ANSWER -To store, retrieve, and
manage data
What are the benefits of using a DBMS? - CORRECT ANSWER -Data independnce (don't
need to know how data is organized), Efficient data access (indexes), data administration (one
location where data is stored), concurrent access + crash recovery, data integrity + security,
reduced app development time (don't have to worry about scalability of database or database
performance)
What is a data model - CORRECT ANSWER -collection of concepts for describing data.
The mathematical equation that defines a relationship.
What is a schema? - CORRECT ANSWER -A description of a particular collection of data
in tables using a given data model. Description of data using tables in the relational model
What are the three levels of abstraction? - CORRECT ANSWER -External Schema
(Views), Conceptual Schema, and Physical Schema
What are the external schema (views)? - CORRECT ANSWER -Describes how users see
the data. Can have multiple views on top of a conceptual schema.
What is the conceptual schema? - CORRECT ANSWER -Defines the logical structure of
the relation. The attributes that make up the database. Only one conceptual schemal per relation.
What is the physical schema? - CORRECT ANSWER -Describes the files and indexes
used. How the data is sorted, stored, and indexed.