Module 2 - Unit 4 - Using Databases

Question 1

Database

Answer 1

An organized collection of information. The information is stored in a structured manner for easier access.

Question 2

Database processes

Answer 2

a. Creation
b. Import/Input
c. Storage
d. Queries
e. Reports

Question 3

Flat File systems

Answer 3

A system of files in which every file in the system must have a different name. Flat file is used to refer to files that are for data storage

Question 4

Database v.s. Flat File Systems

Answer 4

i. Databases validates and enforce information entered
ii. Databases can create complex schemas
iii. Databases can support more storage
iv Databases are more scalable
vi. Database provide access controls

Question 5

Relational database

Answer 5

A highly structured database where information is organized in tables that contains columns and rows.

Question 6

Primary Key

Answer 6

A unique key in a table and can be used to reference from another table.

Question 7

Foreign Key

Answer 7

When a primary key is referenced in another table, it is called a foreign key.

Question 8

Database Schema

Answer 8

Describes the structure of the database by the relations of foreign and primary keys.

Question 9

Garbage In, Garbage Out (GIGO)

Answer 9

A phrase to describe that if nonsense is inputted into the computer, nonsense will also come out on the other end. This emphasizes the important of input and that it has to conform and are consistent with what the information the field is supposed to store.

Question 10

Database constraints

Answer 10

Constraints are place to enforce data types, or a way to validate the values input into the table.

Question 11

Structured Data

Answer 11

Structured data allow easy access to stored information and gives the flexibility over what to access. Information stored in a relational database is structured.

Question 12

Unstructured Data

Answer 12

Unstructured data provides no rigid formatting of the data. Images and text files, Word documents, and PowerPoint presentations are examples of unstructured data.

Question 13

Semi-Structured Data

Answer 13

This is a structure that lies in between structured and unstructured data. It has metadata that helps identify the data.

Question 14

Document database

Answer 14

An example of a semi-structured database. Rather than define tables and fields, the database grows by adding documents to it. The structure within the documents would commonly use eXtensible Markup Language (XML) to provide structure.

Question 15

Key/Value pair database

Answer 15

Storing the properties of objects without predetermining the filed used to define an object. One use of this is JSON.

Question 16

Database interfaces

Answer 16

Database interfaces are the processes used to add/update information to and extract (or view information) from the database.

Question 17

Relational Methods

Answer 17

There are two main types, those that define the database structure and those that manipulate information in the database.

Question 18

Data Definition Language (DDL)

Answer 18

Refer to SQL commands that add to or modify the structure of the database.
CREATE - creates a table
ALTER TABLE - add, remove and modify table columns
DROP - drops table and database
CREATE INDEX - specify that a column is indexed

Question 19

Data Manipulation Language (DML)

Answer 19

Refer to SQL commands that allow you to inset or update records and extract information from records for viewing.
INSERT INTO - adds a new row in a table in the database
UPDATE - changes the value of one or more table columns
DELETE - deletes records
SELECT - define a query to retrieve data from a database

Question 20

Database permissions

Answer 20

When an account creates an object, it becomes its owner, having complete control over it. In SQL, it can changed using the ALTER AUTHORIZATION statement.

Question 21

Database access methods

Answer 21

Processes by which a user might run SQL commands on the database server or update or extract information using a form or application that encapsulates the SQL commands as graphical controls or tools.

Question 22

Direct/Manual Access

Answer 22

Administrators can use an administrative tool like phpMyAdmin to connect and sign in to an RDBMS database. Once they have connected they can run SQL commands to create new databases on the system and interact with stored data.

Question 23

Query/Report Builder

Answer 23

A query or report builder provides a GUI for users to select action to perform on the database and converts selections to SQL commands.

Question 24

Programmatic Access

Answer 24

A way to access the database using programming languages that comes with libraries that allow a connection to a database and executing queries.

Question 25

User Interface/Utility Access

Answer 25

A GUI or from tailored for users to add and search records

Question 26

Standalone Application

Answer 26

Application that are hosted on the same computer where the front end, processing logic and database engine is hosted on the same computer

Question 27

Two-Tier Application

Answer 27

Applications where the database engine, back end data layer is separated from the presentation and business logic layer, database engine running on a server and the other the client, making it a client-server application

Question 28

Three-Tier Application

Answer 28

Where the presentation and application layer are also split. The presentation layer that provides the user interface runs on the client machine, where the application layer runs on a server that the client connects to. Whenever a request is made, the request is verified by the application layer.

Question 29

What are the structural elements of a database table?

Answer 29

Each table stores information about records (rows in the table) in fields (columns in the tables).

Question 30

What term is used to describe selecting and viewing information in a database?

Answer 30

Query.

Question 31

How does an RDBMS such as Microsoft SQL Server differ from Microsoft Excel when used to store a dataset?

Answer 31

Excel is an example of a flat file system. These do not scale well, and usually support a single user only. RDBMS platforms enable many hundreds or thousands of users to connect concurrently, and can support very large datasets. Also, an RDBMS can enforce data types for each column and validate information entered as fields and records.

Question 32

What language is usually used to request data from an RDBMS such as Oracle?

Answer 32

Structured Query Language (SQL) is used to query RDBMS-based database platforms.

Question 33

What is it that defines the relationship between tables in an RDBMS?

Answer 33

Each table contains a primary key whose value is unique for each record in the table. A foreign table can use the value of a primary key as a relation, storing the value in a foreign key field.

Question 34

Give an example of unstructured data

Answer 34

Images and text files and other document formats are unstructured data.

Question 35

Give two examples of semi-structured data stores.

Answer 35

Key/value pair databases and markup language document stores.

Question 36

Is an INSERT statement an example of a definition or manipulation language statement?

Answer 36

Manipulation language--it depends on the structure of a table (columns, data types, and constraints) being established already.

Question 37

You need a development environment with a library of database functions. What type of interface are you using?

Answer 37

Programmatic access.

Question 38

How can a client-server application architecture be described if there is the potential for the structure of the application platform to be developed further?

Answer 38

This could be described as a two-tier application. It could be re-developed as a three-tier application by specifying presentation, application, and data layers.