...The Need for Normalization The aim of normalization is to put the data into tables in its simplest forms. We normalize the relational database management system because of its following characteristics and features. They are: 1. It helps to minimize data redundancy i.e. there should not be any multivalued attributes. Moreover eliminating the repeating groups. 2. Helps to make database structure flexible. It means it could allow to add new data values and rows in a relation structure without reorganizing the database structure. 3. To make consistency of data throughout the database i.e. it should not suffer from anomalies as given below: a. Insert Anomaly – It occurs due to lack of data i.e. data items are scattered and are not linked to each other properly, then it could lead to strange situations. This kind of anomaly can cause serious damage to the database b. Update Anomaly – It occurs because of data redundancy i.e. same value occurs multiple times in a column. This leads to inefficiency. c. Deletion Anomaly - It leads to the loss of data from rows that are not stored anywhere in the database. This could result in loss of vital data. 4. It is easy to handle complex queries that are required by the users. 5. *On decomposition of a relation into smaller relations with fewer attributes on normalization the resulting relations whenever joined must result in the same relation without any extra rows. The join operations can be performed in any...
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...MMIS 630 Database Systems – Final Exam 1. What are the issues in the normalization vs. performance trade-off? Discuss. Your essay should (1) define and describe the characteristics of normalization, (2) define and describe the characteristics of performance, and (3) define and describe what is meant by “performance trade-off”, (4) summarize your essay with recommendations and/or guidelines regarding use of normalization in database design. ANS: When we take a close look in designing a database one may not be thinking of normalization and performance, we may just be thinking, “I have this major project due in several months, I do not have time to be considering about formal techniques and performance, I will worry about this later.” Though this may occur in industry, database designers need to keep in mind that utilization of scarce resources such as processor time, network utilization, memory, etc., are very critical and can have a significant impact on database access and retrieval. As I had previously mentioned in our forum, one of the main concerns to keep in mind is that in other fields being 2 or 3 times slower may not be noticeable and certainly may not have a long term affect but in the realm of computers, having a multiplier can be detrimental in our resultant. What does this mean? It would simply mean that 1) Your database is not consistent OR 2) Your database is lacking the performance. Finding the equilibrium in this case can be a task like working...
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...DBM 380 FULL COURSE http://www.learnyourcourse.com/dbm-380/98-dbm-380-full-course.html DBM 380 WEEK 1 DBM 380 Week 1 DQ # 1- Based on the Manegold (2009) article, describe one method of optimizing data retrieval from a high-use database. (There are many such methods mentioned in the article - pick one you like and do a deep dive.) DBM 380 Week 1 DQ # 2- In the course text, there is some discussion of the capabilities of databases, and recognition of these as an evolution beyond file-based storage approaches. Spreadsheets are one example of a file-based approach. What kinds of things can database management systems do that spreadsheets can't? Also, why is it that in spite of the many apparent data management advantages of databases, spreadsheets are frequently used for data storage in all kinds of organizations? DBM 380 WEEK 2 DBM 380 Week 2 Individual Assignment - Database Design Paper DBM 380 Week 2 DQ # 1- Using the Geiger (2009) article as a guide, how must a database administrator balance the time to complete data modeling step with the benefits this step offers in creating a database? DBM 380 Week 2 DQ # 2- What are the issues identified in the Cox (2009) article that a database administrator should know when working with a many-to-many relationship? Identify and discuss one of these issues. DBM 380 WEEK 3 DBM 380 Week 3 Individual Assignment - ERD Creation Project DBM 380 Week 3 DQ # 1- Why do you think the use of icons in entity-relationship diagrams as described...
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...Jonathan Hindman PT2520 Chapter 4 10/18/13 Cardinality: Cardinality refers to the number of allowed instances of a relationship. In the usual cardinality of one to many, for instance, each record on the one side can have zero to any number of records on the many side. Cardinality can be more specific however. Each patron at a library can have only 20 items checked out at once. This has a cardinality of 0 to 20. Composite keys: In database design, a compound key is a key that consists of 2 or more attributes that uniquely identify an entity occurrence. Each attribute that makes up the compound key is a simple key in its own right. Crow’s feet notation: A type of notation for entity relationships in entity relation diagrams that depicts the many side of a relationship with a three-pronged end called a “crows foot.” This type of notation provides more information about the cardinality of a relationship than the arrow notation for relationships. Domain entities: Those database entities that relate directly to the business problem under consideration. Entity relation diagrams: A diagram that shows entities, their attributes, and the relationships among them. Linking entity: An entity used to resolve a many-to-many relationship into two one-to-many relationships. Logical entity: The design of a database without regard to the physical implementation of the database. Lookup entity: An entity used to store lookup values such as state names or zip codes. Maximum cardinality:...
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...Review Questions 1. What are the problems of managing data resources in a traditional file environment and how are they solved by a database management system? List and describe each of the components in the data hierarchy. Figure 6–1 shows the data hierarchy. The data hierarchy includes bits, bytes, fields, records, files, and databases. Data are organized in a hierarchy that starts with the bit, which is represented by either a 0 (off) or a 1 (on). Bits can be grouped to form a byte to represent one character, number, or symbol. Bytes can be grouped to form a field, such as a name or date, and related fields can be grouped to form a record. Related records can be collected to form files, and related files can be organized into a database. Define and explain the significance of entities, attributes, and key fields. • Entity is a person, place, thing, or event on which information can be obtained. • Attribute is a piece of information describing a particular entity. • Key field is a field in a record that uniquely identifies instances of that unique record so that it can be retrieved, updated, or sorted. For example, a person’s name cannot be a key because there can be another person with the same name, whereas a social security number is unique. Also a product name may not be unique but a product number can be designed to be unique. List and describe the problems of the traditional file environment. Problems with the traditional file environment include...
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...Relational Databases Jason A. Mizener Professor Merkel Intro to Information Technology 17 August 2014 Relational Databases As technology as grown throughout the years, so has the information it utilizes. Early on databases were organized through the hierarchical model, which was the earliest representation of the parent-child structure (each parent can have multiple children, but each child can only have one parent). Shortly thereafter the network database model was incorporated to more effectively represent complex data relationships. Large amounts of data became better organized, which improved database performance. Additionally, the parent-child structure was improved to where children could now have multiple parents. Despite these advances, databases continued to grow increasingly cumbersome and complex, and further advances were necessary to keep everything manageable. The relational database, designed in 1970 by E. F. Codd, represented a major breakthrough in database technology for both designers and users alike. The relational model is very simple, yet very effective in concept. As strange as it may be to think, the relational database pioneered the concept of using tables to hold and organize data. An Excel spreadsheet is probably the most obvious example of a relational database that the end user can relate to today. Essentially, a relational database is the logical view, rather than the physical view, of information. (Carlos Coronel, 2013) ...
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... * Real-world entity − A modern DBMS is more realistic and uses real-world entities to design its architecture. It uses the behaviour and attributes too. For example, a school database may use students as an entity and their age as an attribute. * Less redundancy − DBMS follows the rules of normalization, which splits a relation when any of its attributes is having redundancy in values. * Consistency − There exist methods and techniques, which can detect attempt of leaving database in inconsistent state. A DBMS can provide greater consistency as compared to earlier forms of data storing applications like file-processing systems. * Query Language − DBMS is equipped with query language, which makes it more efficient to retrieve and manipulate data. * ACID Properties − DBMS follows the concepts of Atomicity, Consistency, Isolation, and Durability (normally shortened as ACID). These concepts are applied on transactions, which manipulate data in a database. ACID properties help the database stay healthy in multi-transactional environments and in case of failure. * Multiuser and Concurrent Access − DBMS supports multi-user environment and allows them to access and manipulate data in parallel. * Multiple views − DBMS offers multiple views for different users. A user who is in the Sales department will have a different view of database than a person working in the Production department. * Security − DBMS offers methods to impose constraints...
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...21. _____ is an example of a personal DBMS. access 22. _____ is the process of converting a data model into tables, relationships, and data constraints. database design 23. The _____ problem is unique to a multiuser database environment. lost-update _____ show data in a structured context. reports A ______ is a collection of forms, reports, queries, and programs that process a database. database application ______ is a popular enterprise DBMS. DB2 ______ is the most popular diagramming tool for database applications. E-R 27. ______ is the process of converting a poorly structured table into two or more well-structured tables. normalization 28. ______ process logic that is specific to a given business record. application programs ______ softwares assist in creating, maintaining, and manipulating databases. DBMS A(n) _____ DBMS is designed to process large organizational and workgroup databases. enterprise A(n) _____ is a column or group of columns that identifies a unique row in a table. key All the following steps involved in transforming a data model into a relational database design except _____. each attribute of the entity becomes a row of the table Applications use DBMS for all of the following operations except _____ data. exchange 20. 24. 25. 26. 29. 30. 31. 32. Brenda wants to find a particular report query containing sales analysis of the second and third quarter. After accessing the DBMS, she should type in the keyword into a...
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...Kenneth and Laudon, Jane Management Information Systems: Managing the Digital Firm, Ninth Edition, Prentice- Hall Do Review Questions 1, 2, and 5. 1. How does a relational database organize data and how goes it differ from an object-oriented database? * Define and explain the significance of entities: attributes, and key fields. * Define a relation database and explain how it organizes and stores information. * Explain the role of entity-relationship diagrams and normalization in the database design. * Define an Object-oriented database and explain how it differs from a relational database A relational database organizes data into two-dimensional tables also called relations with columns and rows. Each table contains data on an entity and its attributes. Each row represents a record and each column represents an attribute or field. Each table also contains a key field to uniquely identify each record for retrieval or manipulation. An object-oriented database management system (DBMS) stores data and procedures that act on the data as objects, and it can handle multimedia as well as characters and numbers. Entities are the person, place, or thing on which we store and maintain information. Entities have specific characteristics called attributes. Attributes are pieces of information describing a particular entity. Key field is a field in a record that uniquely identifies instances of that record so that it can be retrieved, updated, or sorted. A relational...
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...information relevant Offer Data modelling Facility Restricted to classify of object Structured data format Unstructured data format Provide precise semantics Provide imprecise semantics Complete of query specification Incomplete of query specification Data dictionary system management Item normalization Data transformation and presentation Document database search Backup and recovery management Index database search Data store management Selective dissemination of information...
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...tables, query for specific data conditions, perform computations, can update/delete/insert data. Database System four components: * Database – collection of related tables and other structures * Database Management System DBMS – computer program used to create, process, and administer the database. Receives requests encoded in SQL and translates them into action on the database. Large complicated program licensed by software vendors. * Database Application – Set of one or more computer programs that serves as an intermediary between the user and the DBMS, These programs read or modify data by sending SQL statements to the DBMS. * Users – use the DB Application to keep track of things. Use forms to read, enter, and query data. Database – defined as self-describing (a description of the structure if the database is contained within the database itself) relational collection of tables. Metadata – data about the structure of the a database. (IE names of tables, names of columns, and the tables in which they belong, properties of tables and columns) Database contents – user data, metadata, indexes, and other overhead data (these improve performance). Application data (describes application elements, such as forms and reports) DBMS examples –...
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...database? relational Using a file-oriented approach to data and information, data is maintained in many separate files. 3. File-oriented approaches create problems for organizations because of multiple master files which may contain redundant data. 4. Which statement is true regarding file systems? The proliferation of master files creates problems in the consistency of specific data stored in different files. 5. A set of interrelated, centrally coordinated files is called a database. 6. The software program that creates, manipulates, and accesses the database goes by the acronym DBMS. 7. The ___________ acts as an interface between the database and the various application programs c) Database management system 8. The combination of the database, the DBMS, and the application programs that access the database through the DBMS is referred to as the c) Database system 9. The person responsible for the database is the b) Database administrator 10. All of the following are benefits of database technology except: b) Decentralized management of data 11. Separating the logical and physical views in a database allows the programmers to concentrate on coding the application logic b) since they do not have to focus on the physical location and layouts of various data items. 12. A database system separates the logical and physical view of data. Such separation facilitates the development of new applications since programmers...
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...Data Warehousing Methodologies Using a common set of attributes to determine which methodology to use in a particular data warehousing project. DATA INTEGRATION TECHNOLOGIES have experienced explosive growth in the last few years, and data warehousing has played a major role in the integration process. A data warehouse is a subjectoriented, integrated, time-variant, and nonvolatile collection of data that supports managerial decision making [4]. Data warehousing has been cited as the highest-priority post-millennium project of more than half of IT executives. A large number of data warehousing methodologies and tools are available to support the growing market. However, with so many methodologies to choose from, a major concern for many firms is which one to employ in a given data warehousing project. In this article, we review and compare several prominent data warehousing methodologies based on a common set of attributes. Online transaction processing (OLTP) systems are useful for addressing the operational data needs of a firm. However, they are not well suited for supporting decision-support queries or business questions that managers typically need to address. Such questions involve analytics including aggregation, drilldown, and slicing/dicing of data, which are best supported by online analytical processing (OLAP) systems. Data warehouses support OLAP applications by storing and maintaining data in multidimensional format. Data in an OLAP warehouse is extracted and loaded...
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...| National Park Service System | Normalization Summary | Thurmond Burdette 4-14-2015 | In this summary you will understand the importance of normalization for this project. Normalization is the process the team used to efficiently organize data within the database. The goal of this process is to remove repeated data such as storing the same data in more than one table, and ensuring data dependencies. The ultimate goals of the normalization process ensures that redundancy is reduced and that data is organized so that it is relatable, decreases database space allowing the data to be understood. The NPS (National Park Service) has contracted with our organization to track data of visitation to all 51 of their parks which have recently experienced an increase in visitation. The data will reflect how work load demand and distribution affect funding and salary increases going forward. Presently utilizing Microsoft Access the NPS has used this relational database to keep data up to date and would like our analysts to create a “back-end” process for the system currently being used. The Normalization Process streamlines the above process by using guidelines that begins with the lowest form up to the fifth normal form. The first and second normal form sets a framework for the data to be organized and addresses duplication of data. The data tables in these two steps are organized independently and clearly identifiable. The Second normal form...
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...Week 5 Summary Report DBM/380 February 16, 2015 Devin Dickens Week 5 Summary Report Our learning team is getting off to a great start to our assignment we have created Visio diagrams to design and organize our database. We have also got started with the beginnings of the database by working to set up the tables that we are going to be using. We have also begun work on creating our PowerPoint presentation for the project. It has been a busy week with varied schedules, but we have sectioned the work off and kept in touch this has served us well. We followed the link to Entities and Attributes for the Fleet Truck Maintenance page and have been working on how we are going to incorporate them all into our design. We will use relational links where applicable to tie all the tables together and select appropriate primary keys for our tables. We have also gone through the process of assigning appropriate data types for your fields. All in all, I think that we are off to a good start and are looking forward to adding to our project over the coming weeks. Week 3 Summary Report Our team was required to create documentation that explains the process of creating the entity-relationship diagram (ERD) in the change request for our project. We have three parts for our ERD: Vehicles, Parts, and Maintenance. Part One: Vehicles Our entities for the first part of our ERD are Vehicles, Vehicle Types, and Vehicle Maintenance. Our attributes for the entity Vehicle consist of VIN...
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