...Chapter 2 Data Models Chapter 2Data Models Answers to Review Questions 1. Discuss the importance of data modelling. A data model is a relatively simple representation, usually graphical, of a more complex real world object event. The data model’s main function is to help us understand the complexities of the real-world environment. The database designer uses data models to facilitate the interaction amongdesigners, application programmers, and end users. In short, a good data model is a communicationsdevice that helps eliminate (or at least substantially reduce) discrepancies between the databasedesign’s components and the real world data environment. The development of data models, bolstered by powerful database design tools, has made it possible to substantially diminish thedatabase design error potential. (Review Section 2.1 in detail.) 2. What is a business rule, and what is its purpose in data modelling? A business rule is a brief, precise, and unambiguous description of a policy, procedure, or principle within a specific organization’s environment. In a sense, business rules are misnamed: they apply to any organization -- a business, a government unit, a religious group, or a research laboratory; large or small -- that stores and uses data to generate information. Business rules are derived from a description of operations. As its name implies, a description of operations is a detailed narrative that describes the operational environment of an organization. Such a...
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...Business Rules and Data Models Insert Name Insert Course Insert Date Business Rules and Data Models Big organizations like universities, colleges, banking and hospitals with large amount of data require a software that is able to organize the data and in the database. Therefore the primary use of a database management system is its ability to collect data, store and transmute it into informative information that can help business make decisions. In order to make this possible, a database must be able to reduce data redundancy, inconsistency, upsurge security features, reliability and allow concurrent access of the data and improve accuracy and accuracy. The most important purpose of such a database is to provide automated methods that are able to develop, store and retrieve data more efficiently (Chapman, 2014). There are several drawbacks that are associated with the use of conventional file systems. This is because of the fact that most of such databases applications are developed on top of an existing file system. For this reason, the following problems are expected. To begin with, is redundancy; it is a situation where a lot of file formats together with duplicate information is found in different files (Gillenson, 2005). Accessing such data is difficult and the duplication of data in a file system may sometimes require a new program to be written. Another problem associated with conventional file systems is the difficult in file isolation. This is...
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...Database Final Exam review 1. What is data? Data are values of qualitative or quantitative variables, belonging to a set of items 2. What is information? Data becomes information after it has been processed to add context, relevance and purpose. 3. Role of data and information – Data and information allow users to make better decisions based on good information and data 4. Field – a column in a table which is a property of an entity (attribute) 5. Record – A row or tuple in a table 6. Tuple – A record or row in a table 7. ACID - ACID stands for Atomicity, Consistency, Isolation, and Durability. Atomicity means if one part of the transaction fails, all of the transaction fails, leaving the database unchanged. Consistency means the data written must be valid according to all the rules and the rules are applied from state to state. Isolation means that the data used during the execution of a transaction cannot be used by a second transaction until the first one is completed. It is executed as if it were being executed serially. Durability ensures that once transaction changes are done, they are permanent and cannot be undone or lost, even in the event of a system failure. 8. What is data redundancy and which characteristics of the file system can lead to it? Data redundancy exists when unnecessarily duplicated data are found in the database. It is the result of poorly designed databases which allow the data to be stored in different locations...
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...Assignment 1: Business rules and Data Models CIS 111: Introduction to Relational Database Management Systems Purpose of Database Spellman University had requested that I develop a database for their college. The purpose of the database will be to track the students and the courses. There also will be a place in the system to track the instructors teaching each course. There are many things to be considered in composing this database. This paper will outline the entities, attributes for each entity, the type of relationship, constraints, some business rules, and the conceptual and physical models. Entities and Attributes of Database There will be three main entities in the system; the students, the instructors and the courses. The students’ attributes would be last name, first name, social security number, and phone number, date of birth, address, student ID, level of education, enrollment date, GPA, any standardized test scored, all accepted credits, and their class schedule. The attributes for the instructors would be last name, first name, teacher ID, salary, address, telephone numbers (and or extensions), certifications, degrees, and the course code that they will be teaching. The courses attributes would be a specific course code. Along with the course code each individual class would have to have a code as well. This would make the system easier to keep track of instead of having it spelled out next to either the instructors' or the student's name. The relationship...
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...of same data in multiple places unnecessarily is called data redundance. the use of poorly designed databases or the use of spread sheets and tables that allow the same data to be kept in different locations are the characteristics of the file system can cause the data redundancy. 2. Explain the difference between data and information. |DATA | INFORMATION | | Raw facts is called Data |Processed data to reveal the meaning behind the facts is called | | |Information. | | Data constitute the building blocks of information |Information is produced by processing data | | |Information is used to reveal the meaning of data. | | |Good relevant and timely information is the key to good decision | |Data is the key component to an organization |making. | 3. List and describe the different types of databases Databases may be classified by- a. Number of users supported (single-user, desktop, multiuser, workgroup...
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...Modern Database Management – CGS1540 Exam 1 Study Guide ------------------------------------------------- Chapter 1: The Database Environment and Development Process Data – Facts, text, graphics, images, etc./stored representations of objects and events that have meaning and importance in the user’s environment Database – application program(s)/an organized collection of logically related data Constraint – a rule that cannot be violated by database users/ Repository – centralized storehouse for all data definitions/knowledge base of all data definitions, data relationships, screen and report formats, and other systems Metadata – includes data definitions and constraints/ data that describe the properties or characteristics of end-user data and the correct of those data Data warehouse – integrated decision support database whose content is derived from the various operational databases Information – data placed in context or summarized/ increases the knowledge of user using the data User view – logical description of portion of database Database management system – a software application that is used to create, maintain, and provide controlled access to user databases Data independence – separation of data description Database – organized collection of related data Enterprise resource planning (ERP) – a business management system that integrates all functions of the enterprise Systems Development life cycle (SDLC) – a...
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...Assignment 1: Business rules and Data Models Darryl W Anderson CIS 111: Introduction to Relational Database Management Systems Kean University requested that I develop a database for their college. The purpose of the database will be to track the students and the courses. They also want a place in the system to track the instructors teaching each course. There are many things that need to be considered in developing this database. This paper will outline the entities, attributes for each entity, the type of relationship, constraints, some business rules, and the conceptual and physical models. There will be three main entities in the system; the students, the instructors and the courses. First, the students’ attributes will include; last name, first name, social security number, phone number, date of birth, address, student ID, level of education, enrollment date, GPA, any standardized test scored, all accepted credits, and their class schedule. Next the courses attributes will include the course name and specific class code. Finally, the attributes for the instructors will include the last name, first name, teacher ID, salary, address, telephone numbers, certifications, degrees, and the course and class code they are teaching. This will make the system easier to keep track of instead of having it spelled out next to either the instructors' or the student's name. The relationship of this database would be a many-to-many relationship. This would be because each class can...
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...data are stored unnecessarily at different places. This can lead to poor data security, and data inconsistency. 3. What is data independence, and why is it lacking in file systems? b. Data independence is when you change the data storage characterizes and it doesn’t affect the program’s ability to access the data. 4. What is a DBMS, and what are its functions? c. A DBMS (database management system) is a collection of program that stores and manages data and control access to the data in the collection. It is responsible for creating, editing, deleting and maintain all the data inserted. 5. What is structural independence, and why is it important? d. Access to a file is dependent on the structure of the database. Without structural independence new changes such as adding a field, or a decimal in a record would make the new file or query inoperable and unusable. 6. Explain the differences among data, information, and a database. e. Data: raw information that has not yet been processed. It refers to the collection of facts stores in the database. Example is a date of birth. Medical record number, etc. f. Information is usually used interchangeably with data; however they...
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...trillion of bytes of data is being generated by enterprises especially in telecom sector. To achieve level best decisions for business profits, access to that data in a well-situated and interactive way is always a dream of business executives and managers. Data warehouse is the only viable solution that can bring that dream into a reality. The enhancement of future endeavors to make decisions depends on the availability of correct information that based on quality of data underlying. The quality data can only be produced by cleaning data prior to loading into data warehouse. So correctness of data is essential for well-informed and reliable decision making. The framework proposed in this paper implements robust data quality to ensure consistent and correct loading of data into data warehouse that necessary to disciplined, accurate and reliable data analysis, data mining and knowledge discovery. Significant amounts of time and money are consequently spent on data cleaning, the task of detecting and correcting errors in data. Data cleaning is to deal with the dirty data in data warehouse so as to keep high data quality. The principal of data cleaning is to find and rectify the errors and inconsistencies for the data. 2. One study estimates this combined cost due to bad data to be over US$ 30 billion in year 2006 alone [5]. As business operations rely more...
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...a spreadsheet showing all of a company's beach ball products sold in Florida in the month of July, compare revenue figures with those for the same products in September, and then see a comparison of other product sales in Data visualization Extract, transform, load (ETL) Florida in the same time period. To facilitate this kind of analysis, OLAP data is stored in a multidimensional database. Whereas a relational database can be thought of as two-dimensional, a multidimensional database considers each data attribute (such as product, geographic sales region, and time Association rules (in data mining) Relational database period) as a separate "dimension." OLAP software can locate the intersection of dimensions (all products sold in the Eastern region above a certain price during a certain time period) and display them. Attributes such as time periods can be broken down into subattributes. Denormalization OLAP can be used for data mining or the discovery of previously Master data management (MDM) undiscerned relationships between data items. An OLAP database does not Predictive modeling needed for trend...
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...Assignment 1: Business Rules and Data Models A database is an incorporated PC structure that stores end-user information and metadata (Leake, A.). Data is the raw format of information, which when structured properly, it can produce accurate, relevant, and timely information that is the key to making a good database management system. The true purpose of a database is to provide computer-based systems a way in which to store, manage, and retrieve data quickly. A local college has tasked me to develop a database that will keep track of students and the courses that they have taken. In addition to tracking the students and courses, the client wants me to make the database keep track of the instructors teaching each of the courses. The local college database, will be to store the data of enrolled students, the courses offered and class schedule, and the information of the instructors. The database will provide course matches for each student based off previous courses taken and pre-requisites obtained, as well as keep track of the instructors that are teaching the class. The database will provide the data a student needs to insure they are taking the correct courses and provide the college and the faculty general student information, such as student ID. Entities (Tables) are defined as a person, place, thing, or event in which data is collected and stored. Each entity is a unique object that may be a physical or abstract object within real life (for example:...
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...INFORMATION Operational Information - used to day to day operations Example information needed by a shopkeeper: Daily sales account List of low stock items to be re-ordered List of overstock items Long overdue payments Profit loss account Tactical information - used to improve profitability Example information needed by a shopkeeper: Slow or fast moving items Reliable supplier of items Sales trends Strategic Information - information to expand business and explore new opportunities Example information needed by a shopkeeper: Whether to stock different varieties of items Whether to diversify Whether to start a new branch in a different locality Whether to start an e-shop Statutory Information - used to provide information to the government Example information needed by a shopkeeper: Income tax account Sales tax account MANAGEMENT HIERARCHY AND INFORMATION NEEDS QUALITIES OF INFORMATION Accurate Complete Timely Trustworthy Relevant Brief Up-to-date SignificanceEnsure correct input and processing rules Include all data Give at the right time Do not hide unpleasant information Understand user needs Summarize relevant information Include all data up to present time Use attractive formats and graphical charts Information System - consists of all the components that work together to process data and produce information all contributing to the organization’s main goal. COMPONENTS OF AN INFORMATION SYSTEM Data Input that the system takes to produce...
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...their daily business, the company is proposing the development of a centralized database that the managers can use to track the daily business of their apartment building and to prepare their reports * Constraints: The database will contain only lease, rent payment, and Maintenance Request. Any others will have to be built at extra cost. * Objectives: Create a database that will encompass all of Wildwood Apartment managers requirement for Quarterly reporting * Tasks and Timeline: * Gathering Data: Initial Interviews. * Time allotted: 3 Weeks * Deliverable: A list of scheduled interviews and observations, text of the questionnaires * Analyzing Data: The data gathered will be analyzed to determine business rules and preliminary data modeling. * Time allotted: 2 weeks * Deliverable: List of business rules to be reviewed, basic entities and attributes * Normalization: The data model will be completed with entities and relationships normalized. * Time allotted: 1 week * Deliverable: Entity Relation Diagram for Review * Building the Physical Database: The data model will be translated to the Relational Database Management system. Tables, Columns with specific data types and Relational and other * Time allotted: 3 days * Deliverable: The Schema of the database for review * Testing and Security: Sample data will be entered and each of the business rules and...
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...and Clustering Next Generation Techniques: Trees, Networks and Rules Each section will describe a number of data mining algorithms at a high level, focusing on the "big picture" so that the reader will be able to understand how each algorithm fits into the landscape of data mining techniques. Overall, six broad classes of data mining algorithms are covered. Although there are a number of other algorithms and many variations of the techniques described, one of the algorithms from this group of six is almost always used in real world deployments of data mining systems. I. Classical Techniques: Statistics, Neighborhoods and Clustering 1.1. The Classics These two sections have been broken up based on when the data mining technique was developed and when it became technically mature enough to be used for business, especially for aiding in the optimization of customer relationship management systems. Thus this section contains descriptions of techniques that have classically been used for decades the next section represents techniques that have only been widely used since the early 1980s. This section should help the user to understand the rough differences in the techniques and at least enough information to be dangerous and well armed enough to not be baffled by the vendors of different data mining tools. The main techniques that we will discuss here are the ones that are used 99.9% of the time on existing business...
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...This page intentionally left blank Te n t h E d i t i o n MODERN DATABASE MANAGEMENT Editorial Director: Sally Yagan Editor in Chief: Eric Svendsen Executive Editor: Bob Horan Editorial Project Manager: Kelly Loftus Editorial Assistant: Jason Calcano Director of Marketing: Patrice Lumumba Jones Marketing Manager: Anne Fahlgren Marketing Assistant: Melinda Jensen Senior Managing Editor: Judy Leale Project Manager: Becca Richter Senior Operations Supervisor: Arnold Vila Operations Specialist: Ilene Kahn Senior Art Director: Jayne Conte Cover Designer: Suzanne Behnke Cover Art: Fotolia © vuifah Manager, Visual Research: Karen Sanatar Permissions Project Manager: Shannon Barbe Media Project Manager, Editorial: Denise Vaughn Media Project Manager, Production: Lisa Rinaldi Supplements Editor: Kelly Loftus Full-Service Project Management: PreMediaGlobal Composition: PreMediaGlobal Printer/Binder: Edwards Brothers Cover Printer: Lehigh-Phoenix Color/Hagerstown Text Font: Palatino Credits and acknowledgments borrowed from other sources and reproduced, with permission, in this textbook appear on appropriate page within text. Microsoft® and Windows® are registered trademarks of the Microsoft Corporation in the U.S.A. and other countries. Screen shots and icons reprinted with permission from the Microsoft Corporation. This book is not sponsored or endorsed by or affiliated with the Microsoft Corporation. Copyright © 2011, 2009, 2007, 2005, 2002...
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