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True or false, sources of dat are becoming larger and more diverse ANS True, Billions or even trillions of
data sources
What is the goal of data processing? ANS To extract data that is useful
Why is the volume of data that is available so large? ANS 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? ANS A petabyte (1 million GB)
What is scalable data processing? ANS 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? ANS Relational DBMS, NoSQL Graph/Document
Key Value Stores, and Hadoop/Spark
What are the characteristics of a Relational DBMS? ANS 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? ANS Unstructured data,
highly available systems. Runs queries that extract knowledge from the data.
What are the characteristics of Hadoop/Spark? ANS Not operational, for analytics over massive scale data
What is a database? ANS 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? ANS To store, retrieve, and manage data
, What are the benefits of using a DBMS? ANS 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 ANS collection of concepts for describing data. The mathematical equation that
defines a relationship.
What is a schema? ANS 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? ANS External Schema (Views), Conceptual Schema, and Physical
Schema
What are the external schema (views)? ANS Describes how users see the data. Can have multiple views on
top of a conceptual schema.
What is the conceptual schema? ANS 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? ANS Describes the files and indexes used. How the data is sorted, stored,
and indexed.
What is logical data independence? ANS Protection from changes in logical structure.
What is physical data independence? ANS Protection from physical structure of data.
Why are logical and physical data independence so beneficial? ANS The application that is accessing the
database is not affected by changes in the logical structure or physical structure in the database thanks to the
DBMS
What are the thee phases of Database Design? ANS "1: Requirement analysis (what users expect)
2: Conceptual database design (build entity relationship (ER) diagram)
3: Logical database design (convert ER design into a relational database schema."