Database Design: 1. Introduction
Server
A more powerful computer that accepts work requests for clients, executed each request, and sends the results back to the clients - Every time you request information from a Web page, your client computer sends the request to a database on the server - The server retrieves the data from the database, converts it into useful information, and sends the information back to the client
History of Database: 1960s
Computers became cost effective for private companies, and storage capacity increases
History of Databases: Mid-1990s
Kaboom! The usable Internet/WWW appears
Software
Programs (sets of instructions) which tell the hardware what to do
Hardware
The physical "bits and pieces" of a computer: keyboard, screen, mouse, disk drive, memory
The demand for Information Technology professionals in today's market is increasing. True or False?
True
Application
A software program which carries out specific tasks on behalf of computer users
Client
A workstation or desktop computer including a screen, keyboard, and mouse; clients interact directly with human computer users
History of Databases: Early 1990s
An industry shakeout begins with fewer surviving companies. Oracle survives
Cloud Computing
the practice of using a network of remote servers hosted on the Internet to store, manage, and process data, rather than a local server or a personal computer. Using someone else's computer.
History of Computer Systems: 1980s
- PCs became faster and more widely available; processing moved to desktops and became known as smart clients or workstations - having the processing power within the client machine ushered in a wave of graphical user interface (GUI) applications - many common applications were born during this era - but, these were isolated, non-integrated machines
History of Computer Systems: 1970s
- The database software resided in the mainframe computer, where processing was done - smaller computers, or dummy terminals, were used to access the large mainframe and execute commands
History of Computer Systems: 1990s and Beyond
- The software that manages the data is on the database server; it performs processing for storage and retrieval - applications for business operations sit on the application server; it interacts with, processes, develops, or manipulated the data for document creation - Clients provide access to and visual display of the information on the servers - Clients can have their own applications, but the essential business applications are accessed from the clients using an Internet browser
Data Modeling in the Database Development Process
Begins by researching the information requirements of a business. An entity relationship diagram should completely capture and accurately model the organization's information needs and functions of the business
How do you turn "data" into "information"?
By querying it or accessing it
Consider your school library. It will have a database with transaction details of the books that are borrowed by students. Is a detail of one student borrowing one book considered Data or Information?
Data
Consider your school library. It will have a database with transaction details of the books that are borrowed by students. Is the total number of books out on loan in one given month considered Data or Information?
Data
What is the difference between information and data?
Data turns into useful information. It is stored in a database and accessed by systems and users.
History of Databases: 1970-72
E.F. Codd proposes the relational model for databases, disconnecting the logical organization from the physical storage
Data Modeling is the last step in the database development process. True or False?
False
Personal computers (PCs) have been in existence since 1950. True or false?
False
Which term describes the physical components of a computer system?
Hardware
Users could directly interact with which of the following software to access essential business applications? (Choose three) Server software Internet Browser Software Operating System software GUI Software
Internet Browser Software Operating System software GUI Software
Information which was gained from data is the same as: (Choose Two) Intelligence Knowledge Raw Materials There is no difference between data and information
Knowledge and Intelligence
What is Information?
Often the result of combining, comparing, analyzing, or performing calculations on data (ex: a class' average score on a test)
What is Data?
Raw or unprocessed information (ex: students' test scores)
History of Databases: Mid-1980s
SQL (structured query language) becomes "intergalactic standard"
History of Databases: Early 21st Century
Solid growth of DB applications continues
Oracle's Mission
To use the Internet and fast processing servers to meet the needs of organizations in storing data and producing information
Every time you shop online, it is likely you will be accessing a database. True or False?
True
In the grid computing model, resources are pooled together for efficiency. True or false?
True
Most of the well known Internet search engines use databases to store data. True or false?
True
SQL became the most commonly used query language in the 1980s. True or False?
True
SQL commands in the Database Development Process
Used to build the physical structure of the database. Also used to populate, access, and manipulate the data within the relational database
Changes in computing have affected many of our day-to-day activities. Are all of the following activities examples of this change? Yes or No? In the past you used to use the phone system to call directory assistance to get a phone number. Today you can use your PC to look up a phone number online. In the past you used to have to go to the shoe store to buy shoes. Today you can use your PC to order shoes online. In the past you had to use your PC to send a person an email. Today you can use your phone to send a text message.
Yes
The main subject areas taught by the Oracle Academy are which of the following: Data Modeling, SQL, and PL/SQL Computer Repairs Database performance tuning Systems programming and computer architecture
Data Modeling, SQL, and PL/SQL
The market for IT professionals is still increasing and will continue to do so in the future as the world gets ever more dependent on computer systems. True or False?
Yes
The Problem of Isolated, Non-Integrated Systems
- Having multiple applications on multiple client workstations created new problems in the 80s - Different software on different systems requires integration, which is usually troublesome and expensive - If an upgrade is made to a software application, each and every server plus each and every client must be upgraded
Data Modeling
The first step in the database development process. Involves collecting and analyzing the data that a business needs to track, and then diagramming the organization of that data in an Entity Relationship Diagram
What is a database?
A centralized and structured set of data stored on a computer system that provides facilities for retrieving, adding, modifying, deleting the data when required and facilities for transforming retrieved data into useful information Stores raw data which, when queried, transforms into information
Table instance chart
A relational database chart that is used to map the information from the entity relationship diagram. Has the following components: 1. Table name 2. Columns names 3. Keys: primary key and foreign key 4. Nulls: indicates if a column must contain a value (mandatory) 5. Unique: indicates if the value contained in a column is unique within the table 6. Data type: Identifies the definition and format
Operating System
A software program which directly controls and manages the hardware: Microsoft Windows, Linux, etc.
History of Databases: Late 1990s
The large investment in Internet companies helps create a tools-market boom for Web/Internet/DB Connectors
Grid Computing
All of an organization's computers in different locations can be utilized just like a pool of computing resources. A user makes a request for information or computation from their workstation and that request is processed somewhere in the grid in the most efficient way possible.
What is the correct sequence of steps in the Database Development Process?
Analyze, Design, Build
History of Databases: 1976
P. Chen proposes the entity relationship model (ERM) for database design
History of Databases: Early 1980s
The first commercially-available relational database systems start to appear at the beginning of the 1980s with Oracle Version 2
Database design phase of the database development process
Translates information modeled on the entity relationship diagram to a table instance chart