Oracle CH1 & CH2
Computers become cost effective for private companies along with increased storage capability
1960s
E.F. Codd proposes the relational model for databases, disconnecting the logical organization from the physical storage.
1970-72
P. Chen proposes the entity relationship model (ERM) for database design.
1976
Application
A software program which carries out specific tasks on behalf of computer users
Instance
An occurrence or example of an entity
Table instance chart
A relational database chart that is used to map the information from the entity relationship diagram
Unique Identifiers:
Distinguish one instance of an entity from all other instances of that entity
The first commercially-available relational database systems start to appear at the beginning of the 1980s with Oracle Version 2.
Early 1980s
An industry shakeout begins with fewer surviving companies. Oracle survives.
Early 1990s
To be described as implementation-free, a data model must be changed to accommodate the database system onto which it is built.
False
Once you have learned how to write programs and build systems, you no longer need any input or involvement from any users as you are perfectly capable of delivering the systems that businesses need and want.
False. Business requirements can and will change. For instance, new legal requirements may arise.
What is conceptual model based on?
Is based on current needs but it may reflect future needs. It addresses the needs of a business (what is conceptually ideal), but does not address its implementation (what is physically possible)
Optional
Not required
Data modeling
The process of capturing the important concepts and rules that shape a business and depicting them visually on a conceptual model
The demand for Information Technology professionals in today's market is increasing. True or False?
True
A/an _________ is a piece of information that in some way describes an entity. It is a property of the entity and it quantifies, qualifies, classifies, or specifies the entity.
Attribute
A/an _________'s value can be a number, a character string, a date, an image, a sound
Attribute
Which of the following statements about Entities are true?
- "Something" of significance to the business about which data must be known. - They are usually a noun. - A name for a set of similar "things"
Mandatory
required
Primary key (PK)
the unique identifier for each row of data
Which are the 4 goals of entity relationship modeling?
−Capture all required data −Ensure that data appears only once −Model no data that is derivable from other data already modeled −Locate data in a predictable, logical place
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.
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?
Information
A specialized type of software, which controls and manages the hardware in a computer system.
Operating system
Tangible
Perceptible to the senses, especially the sense of touch
What are Structured Query Language (SQL) commands used for?
Structured Query Language (SQL) commands are used to build the physical structure of the database. It is also used to populate, access, and manipulate the data within the relational database
The purpose of an ERD is to document the proposed system and facilitate discussion and understanding of the requirements captured by the developer. True or False?
True
The work of E.F. Codd in the early 1970s led to the development of Relational databases. True or False?
True
Attribute
A characteristic; something that describes, quantifies, or specifies an entity
Entity relationship diagram (ERD)
A drawing that is used to represent a data model.
Which of the following represents the correct sequence of steps in the Database Development Process?
Analyze, Design, Build
How do you turn "data" into "information"?
By querying it or accessing it
Single Valued
Can only have one value at any point for each instance in the entity
The word "Volatile" means:
Changing constantly; unstable
The main subject areas taught by the Oracle Academy are:
Data Modeling, SQL, and PL/SQL (*)
Software cannot operate without Hardware. True or False?
True
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
If Building the database is the third major task in the database development process then what are the first two major tasks?
Data Modeling and Database Design
Which term describes the physical components of a computer system?
Hardware
Volatile
Highly changeable
SQL (structured query language) becomes "intergalactic standard."
Mid-1980s
Kaboom! The usable Internet/World Wide Web (WWW) appears. A mad scramble ensues to allow remote access to computer systems with legacy data.
Mid-1990s
All of the following could be attributes of an ENTITY called PERSON, except which one?
Natacha Hansen
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
What does conceptual modeling identify?
important entities and relationships among entities
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
Oracle was one of the first relational database systems available commercially. True or False?
True
SQL became the most commonly used query language in the 1980s. True or False?
True
The Personal Digital Assistant (PDA) was an important historical contribution in database development and design.
True
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?
True
To be described as implementation-free, a data model must not change to accommodate the database system onto which it is built.
True
Which of the following are examples of ENTITY: Instance ?
- ANIMAL: Dog - TRANSPORTATION METHOD: Car
Information which was gained from data is the same as:
- Intelligence - Knowledge
In the following statements, find two good examples of ENTITY: Instance.
- BOOK: Biography of Mahatma Gandhi - DAIRY PRODUCT: milk
Which of the following entities most likely contains valid attributes?
- Entity: Home. Attributes: Number of Bedrooms, Owner, Address, Date Built - Entity: Pet. Attributes: Name, Birthdate, Owner
Users could directly interact with which of the following software to access essential business applications?
- GUI software - Internet Browser software - Operating System software
Data modeling is performed for the following reasons:
- It helps discussions and reviews. - The ERD becomes a blueprint for designing the actual system.
Which of the following are examples of e-businesses that use database software?
- Online clothing store - Online book store - Online personal shopping service
Which of the following are examples of data becoming information:
- Student age -> average age of all students in class - Bank deposit amount -> total account balance - Price of a computer -> total sales of all computers for a company
The table instance chart lists the design specifications of the information and has the following components:
- Table name - Column names - PK & FK - Nulls
Datatype
A classification identifying one of various types of data, stating the possible values for that type, the operations that can be done on that type, and the way the values of that type are stored
Database
A collection of data arranged for ease and speed of search and retrieval.
Data
A collection of facts from which conclusions may be drawn
Hardware
A computer and the associated physical equipment directly involved in the performance of data-processing or communications functions.
Conceptual model
A data model, usually represented by an entity relationship diagram
Physical model
A design for an object (a car, a house, a database, etc.) which includes implementation details such as size, volume, weight, etc.)
Grid computing
A global effort to develop an environment in which individual users can access computers, databases, and experimental facilities simply and transparently, without having to consider where those facilities are located
Server
A more powerful computer which accepts work requests from clients, does the work, and sends results back to the client
Entity
A named thing or category of things that is significant to the business and about which data must be known
Null
A value that is unavailable, unassigned, unknown, or empty; however, it is neither a zero nor a space
Client
A workstation or desktop computer including a screen, keyboard, and mouse; communicates directly with the user
Unique Identifier (UID)
Any combination of attributes and/or relationships that serves, in all cases, to uniquely identify an instance of an entity
Solid growth of DB applications continues. Examples: commercial websites (yahoo.com, amazon.com, google.com), government systems (Bureau of Citizenship and Immigration Services, Bureau of the Census), art museums, hospitals, schools, etc.
Early 21st century
An ______ is a consistent tool that can be used to represent data requirements regardless of the type of database used.
Entity Relationship Diagram (ERD)
A well structured ERD will show only some parts of the finished data model. You should never try to model the entire system in one diagram, no matter how small the diagram might be. True or False?
False
Data Modeling is the last step in the database development process. True or False?
False
Entities are usually verbs. True or False?
False
Personal computers (PCs) have been in existence since 1950. True or False?
False
The overall mission of the Oracle Corporation is to use the internet and fast processing servers to build its own network. True or False?
False
Nontangible/ Intangible
Incapable of being perceived by the senses
Nulls
Indicates if a column must contain a valueThis
Unique
Indicates if the value in the column is unique within the table
Information
Knowledge, intelligence, a particular piece of data with a special meaning or function
The large investment in Internet companies helps create a tools market boom for Web/Internet/DB connectors.
Late 1990s
Foreign key (FK)
Links data in one table to the data in a second table by referring to the PK column in the second table
Software
The programs, routines, and symbolic languages that control the functioning of the hardware and direct its operation.
Implementation-free
Not dependent on the physical model.
A specialized type of software, which controls and manages the hardware in a computer system.
Operating System
Every time you shop online, it is likely you will be accessing a database. True or False?
True
Data
Raw material, from which you can draw conclusions
Datatype
Refers to the format and definition of the data in each column
Operating System
Software designed to control the hardware of a specific data-processing system in order to allow users and application programs to make use of it.
A Conceptual Model is not concerned with how the Physical Model will be implemented. True or False?
True
An Entity Relationship model is independent of the hardware or software used for implementation. True or False?
True
Attributes can only have one value at any point for each instance in the entity. True or False?
True
Businesses involved in any of the following typically use databases to handle their data: Finance, Logistics, Commerce, Procurement, and Distribution? True or False?
True
Databases are used in most countries and by most governments. Life, as we know it, would change drastically if we no longer had access to databases. True or False?
True
Documenting Business Requirements helps developers control the scope of the system and prevents users from claiming that the new system does not meet their business requirements. True or False?
True
Entities are transformed into Tables during the Database Design process. True or False?
True
