Comp 1: Intro to Databases

Question 1

What is data?

Answer 1

Numbers, text, visual, or audio info that describes real-world systems.

Question 2

What are three ways data varies?

Answer 2

1. Scope, 2. Format, 3. Access

Question 3

What is a database?

Answer 3

Collection of data in structured format.

Question 4

What is a database system also known as?

Answer 4

Database Management System (DBMS)

Question 5

What does a DBMS do?

Answer 5

software which reads and writes data in database. Ensures security, consistency, and availability.

Question 6

What is a query language?

Answer 6

Specialized programming language for designed for db systems.

Question 7

What is Database Application?

Answer 7

Programmers write the query languages into friendly GUI.

Question 8

What are the 4 Database Jobs?

Answer 8

1. DB Administrator. Secures DB system.
2. DB Designer. Determines format and structure. Storage, response time, and support.
3. DB Programmer. Writes the apps which combine query and general programming languages.
4. DB User. The person who uses it.

Question 9

5 requirements for a database use by many users.

Answer 9

1. Performance
2. Authorization
3. Security
4. Rules
5. Recovery

Question 10

What is a transaction?

Answer 10

Group of queries that must be completed or rejected as a whole. (p^q)

Question 11

What 3 things does a DB do when processing transactions?

Answer 11

1. Ensure p^q. Complete entire transaction or not at all.
2. Prevent conflicts between concurrent transactions.
3. Ensure results are never lost.

Question 12

What is the architecture of the database system?

Answer 12

Internal components and relationship between those components.

Question 13

What are the 5 components of a DB system and what do they do?

Answer 13

1. Query Processor. Interprets and returns results of query.
2. Storage Manager. Translates query processor to low-level file system commands.
3. Transaction Manager. Makes sure transactions are done appropriately. Restores back up if system fails.
4. Log. Contains records of everything.
5. Catalog. Directory of tables, columns, indexes etc.

Question 14

What is big data?

Answer 14

Gigantic clusterfuck of data uploaded to the internet in the 90s and early 2000s.

Question 15

What are non-relational systems called?

Answer 15

NoSQL

Question 16

Are most DB systems Open Source or Proprietary?

Answer 16

Open Source

Question 17

What are the top 5 DB products today?

Answer 17

1. Oracle (proprietary)
2. MySQL (open source)
3. SQL Server (proprietary)
4. PostgreSQL (open source)
5. MongoDB (open source)

Question 18

How was SQL originally developed?

Answer 18

IBM in the 1970s as prototype for relational databases.

Question 19

What is a query?

Answer 19

Command which inserts, retrieves, updates, or deletes data. CRUD (create, read, update, delete)

Question 20

What are 4 common SQL commands?

Answer 20

INSERT, SELECT, UPDATE, DELETE

Question 21

What are the main 4 data types used in CREATE TABLE?

Answer 21

INT
DECIMAL
VARCHAR
DATE

Question 22

What is the analysis phase?

Answer 22

Specifies reqs for DB. Entities, relationships, attributes, etc.

Question 23

What do ER diagrams represent?

Answer 23

Entities, relationships, and attributes.

Question 24

What are the symbols used in ER Diagrams for each represented concept?

Answer 24

• Rectangles = entities
• Lines between = relationships
• Text inside = attributes

Question 25

What is logical design?

Answer 25

Plans the DB. Shows how logic will flow from one piece to another. Also called Schema.

Question 26

What are keys?

Answer 26

Column used to ID individual rows of a table.