Denormalization in Data Warehouse Example
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Further Normalization of the Data Base Relational Model
FURTHER NORMALIZATION OF THE DATA BASE RELATIONAL MODEL E. F. Codd IBM Research Laboratory San Jose, California ABSTRACT: In an earlier paper, the author proposed a relational model of data as a basis for protecting users of formatted data systems from the potentially disruptive changes in data representation caused by growth in the data base and changes in traffic. A first normal form for the time-varying collection of relations was introduced. In this paper, second and third normal forms are defined with the objective of making the collection of relations easier to understand and control, simpler to operate upon, and more informative to the casual user. The question "Can application programs be kept in a viable state when data base relations are restructured?" is discussed briefly and it is conjectured that third normal form will significantly extend the life expectancy of appli- cation programs. Fu909umxk7) August 31,197l Information technolow (IR, Documentetion, etc.) 1. 1. Introduction 1.1 Objectives of Normalization In an earlier paper [l] the author proposed a relational model of data as a basis for protecting users of formatted data systems from the potentially disruptive changes in data representation caused by growth in the variety of data types in the data base and by statistical changes in the transaction or request traffic. Using this model, both the appli- cation programmer and the interactive user view the data base as a time-varying collection of normalized relations of assorted degrees. Definitions of these terms and of the basic relational operations of projection and natural join are given in the Appendix. -
Powerdesigner 16.6 Data Modeling
SAP® PowerDesigner® Document Version: 16.6 – 2016-02-22 Data Modeling Content 1 Building Data Models ...........................................................8 1.1 Getting Started with Data Modeling...................................................8 Conceptual Data Models........................................................8 Logical Data Models...........................................................9 Physical Data Models..........................................................9 Creating a Data Model.........................................................10 Customizing your Modeling Environment........................................... 15 1.2 Conceptual and Logical Diagrams...................................................26 Supported CDM/LDM Notations.................................................27 Conceptual Diagrams.........................................................31 Logical Diagrams............................................................43 Data Items (CDM)............................................................47 Entities (CDM/LDM)..........................................................49 Attributes (CDM/LDM)........................................................55 Identifiers (CDM/LDM)........................................................58 Relationships (CDM/LDM)..................................................... 59 Associations and Association Links (CDM)..........................................70 Inheritances (CDM/LDM)......................................................77 1.3 Physical Diagrams..............................................................82 -
Denormalization Strategies for Data Retrieval from Data Warehouses
Decision Support Systems 42 (2006) 267–282 www.elsevier.com/locate/dsw Denormalization strategies for data retrieval from data warehouses Seung Kyoon Shina,*, G. Lawrence Sandersb,1 aCollege of Business Administration, University of Rhode Island, 7 Lippitt Road, Kingston, RI 02881-0802, United States bDepartment of Management Science and Systems, School of Management, State University of New York at Buffalo, Buffalo, NY 14260-4000, United States Available online 20 January 2005 Abstract In this study, the effects of denormalization on relational database system performance are discussed in the context of using denormalization strategies as a database design methodology for data warehouses. Four prevalent denormalization strategies have been identified and examined under various scenarios to illustrate the conditions where they are most effective. The relational algebra, query trees, and join cost function are used to examine the effect on the performance of relational systems. The guidelines and analysis provided are sufficiently general and they can be applicable to a variety of databases, in particular to data warehouse implementations, for decision support systems. D 2004 Elsevier B.V. All rights reserved. Keywords: Database design; Denormalization; Decision support systems; Data warehouse; Data mining 1. Introduction houses as issues related to database design for high performance are receiving more attention. Database With the increased availability of data collected design is still an art that relies heavily on human from the Internet and other sources and the implemen- intuition and experience. Consequently, its practice is tation of enterprise-wise data warehouses, the amount becoming more difficult as the applications that data- of data that companies possess is growing at a bases support become more sophisticated [32].Cur- phenomenal rate. -
A Comprehensive Analysis of Sybase Powerdesigner 16.0
white paper A Comprehensive Analysis of Sybase® PowerDesigner® 16.0 InformationArchitect vs. ER/Studio XE2 Version 2.0 www.sybase.com TABLe OF CONTENtS 1 Introduction 1 Product Overviews 1 ER/Studio XE2 3 Sybase PowerDesigner 16.0 4 Data Modeling Activities 4 Overview 6 Types of Data Model 7 Design Layers 8 Managing the SAM-LDM Relationship 10 Forward and Reverse Engineering 11 Round-trip Engineering 11 Integrating Data Models with Requirements and Processes 11 Generating Object-oriented Models 11 Dependency Analysis 17 Model Comparisons and Merges 18 Update Flows 18 Required Features for a Data Modeling Tool 18 Core Modeling 25 Collaboration 27 Interfaces & Integration 29 Usability 34 Managing Models as a Project 36 Dependency Matrices 37 Conclusions 37 Acknowledgements 37 Bibliography 37 About the Author IntrOduCtion Data modeling is more than just database design, because data doesn’t just exist in databases. Data does not exist in isolation, it is created, managed and consumed by business processes, and those business processes are implemented using a variety of applications and technologies. To truly understand and manage our data, and the impact of changes to that data, we need to manage more than just models of data in databases. We need support for different types of data models, and for managing the relationships between data and the rest of the organization. When you need to manage a data center across the enterprise, integrating with a wider set of business and technology activities is critical to success. For this reason, this review will use the InformationArchitect version of Sybase PowerDesigner rather than their DataArchitect™ version. -
Aslmple GUIDE to FIVE NORMAL FORMS in RELATIONAL DATABASE THEORY
COMPUTING PRACTICES ASlMPLE GUIDE TO FIVE NORMAL FORMS IN RELATIONAL DATABASE THEORY W|LL|AM KErr International Business Machines Corporation 1. INTRODUCTION The normal forms defined in relational database theory represent guidelines for record design. The guidelines cor- responding to first through fifth normal forms are pre- sented, in terms that do not require an understanding of SUMMARY: The concepts behind relational theory. The design guidelines are meaningful the five principal normal forms even if a relational database system is not used. We pres- in relational database theory are ent the guidelines without referring to the concepts of the presented in simple terms. relational model in order to emphasize their generality and to make them easier to understand. Our presentation conveys an intuitive sense of the intended constraints on record design, although in its informality it may be impre- cise in some technical details. A comprehensive treatment of the subject is provided by Date [4]. The normalization rules are designed to prevent up- date anomalies and data inconsistencies. With respect to performance trade-offs, these guidelines are biased to- ward the assumption that all nonkey fields will be up- dated frequently. They tend to penalize retrieval, since Author's Present Address: data which may have been retrievable from one record in William Kent, International Business Machines an unnormalized design may have to be retrieved from Corporation, General several records in the normalized form. There is no obli- Products Division, Santa gation to fully normalize all records when actual perform- Teresa Laboratory, ance requirements are taken into account. San Jose, CA Permission to copy without fee all or part of this 2. -
Characteristics of Functional Dependencies
Chapter 14 Normalization Pearson Education © 2009 Chapter 14 - Objectives The purpose of normalization. The potential problems associated with redundant data in base relations. The concept and characteristics of functional dependency, which describes the relationship between attributes. How inference rules can identify a set of all functional dependencies for a relation. How to undertake the process of normalization. How to identify 1st, 2nd, 3rd and BCNF Normal Forms. 2 Pearson Education © 2009 Purpose of Normalization Normalization is a technique for producing a set of suitable relations that support the data requirements of an enterprise. The benefits of of Normalization: – easier for the user to access and maintain the data; – take up minimal storage space on the computer. 3 Pearson Education © 2009 Characteristics of a suitable set of relations – The minimal number of attributes necessary to support the data requirements of the enterprise; – attributes with a close logical relationship are found in the same relation; – minimal redundancy with each attribute represented only once with… – exception for attributes that form all or part of foreign keys. 4 Pearson Education © 2009 Data Redundancy and Update Anomalies Data Redundancy and Update Anomalies 5 Pearson Education © 2009 Data Redundancy and Update Anomalies StaffBranch relation has redundant data; the details of a branch are repeated for every member of staff. In contrast, the branch information appears only once for each branch in the Branch relation and only the branch number (branchNo) is repeated in the Staff relation, to represent where each member of staff is located. 6 Pearson Education © 2009 Data Redundancy and Update Anomalies Relations that contain redundant information may potentially suffer from update anomalies. -
Developing an Application Concept of Data Dependencies of Transactions to Relational Databases
Jouni Laakso Developing an Application Concept of Data Dependencies of Transactions to Relational Databases Helsinki Metropolia University of Applied Sciences Master's Degree Information Technology Master's Thesis 18. February 2016 Abstract Author Jouni Laakso Title Developing an Application Concept of Data Depencies of Transactions to Relational Databases Number of Pages 73 pages + 5 appendices Date 18. February 2016 Degree Master of Engineering Degree Programme Information Technology Instructor Pasi Ranne, Senior Lecturer Information systems usually use a relational database to store the application data. The relational database can be used outside of the scope of the application. The information systems has to verify the attributes to be the attributes of the transactions to the relational database. The integrity verification includes the verification of the atomicity of the attribute values and the form of their values matching the attributes type. Integrity verification includes the verification and the checking of the dependency constraints. The dependency constraints are usually other attributes the attributes are dependent on. Applications are reprogrammed for different purposes. It has been noted that a complete information system and a new application program is not always needed in the most simple information systems. Sometimes a database query language is enough to use a relational database. For example an administrator of an application can remove and add users with an SQL-editor. The thesis studies the automatic checking of the attributes of the transactions with consistency and integrity verification. The purpose was to develop a concept automatically checking the integrity and consistency of the applications attributes. With the help of the concept, the quality of the application should improve with the help of the reusable application components and with a generic application to be used in different purposes. -
Database Normalization
Outline Data Redundancy Normalization and Denormalization Normal Forms Database Management Systems Database Normalization Malay Bhattacharyya Assistant Professor Machine Intelligence Unit and Centre for Artificial Intelligence and Machine Learning Indian Statistical Institute, Kolkata February, 2020 Malay Bhattacharyya Database Management Systems Outline Data Redundancy Normalization and Denormalization Normal Forms 1 Data Redundancy 2 Normalization and Denormalization 3 Normal Forms First Normal Form Second Normal Form Third Normal Form Boyce-Codd Normal Form Elementary Key Normal Form Fourth Normal Form Fifth Normal Form Domain Key Normal Form Sixth Normal Form Malay Bhattacharyya Database Management Systems These issues can be addressed by decomposing the database { normalization forces this!!! Outline Data Redundancy Normalization and Denormalization Normal Forms Redundancy in databases Redundancy in a database denotes the repetition of stored data Redundancy might cause various anomalies and problems pertaining to storage requirements: Insertion anomalies: It may be impossible to store certain information without storing some other, unrelated information. Deletion anomalies: It may be impossible to delete certain information without losing some other, unrelated information. Update anomalies: If one copy of such repeated data is updated, all copies need to be updated to prevent inconsistency. Increasing storage requirements: The storage requirements may increase over time. Malay Bhattacharyya Database Management Systems Outline Data Redundancy Normalization and Denormalization Normal Forms Redundancy in databases Redundancy in a database denotes the repetition of stored data Redundancy might cause various anomalies and problems pertaining to storage requirements: Insertion anomalies: It may be impossible to store certain information without storing some other, unrelated information. Deletion anomalies: It may be impossible to delete certain information without losing some other, unrelated information. -
Normalization for Relational Databases
Chapter 10 Functional Dependencies and Normalization for Relational Databases Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Chapter Outline 1 Informal Design Guidelines for Relational Databases 1.1Semantics of the Relation Attributes 1.2 Redundant Information in Tuples and Update Anomalies 1.3 Null Values in Tuples 1.4 Spurious Tuples 2. Functional Dependencies (skip) Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Slide 10- 2 Chapter Outline 3. Normal Forms Based on Primary Keys 3.1 Normalization of Relations 3.2 Practical Use of Normal Forms 3.3 Definitions of Keys and Attributes Participating in Keys 3.4 First Normal Form 3.5 Second Normal Form 3.6 Third Normal Form 4. General Normal Form Definitions (For Multiple Keys) 5. BCNF (Boyce-Codd Normal Form) Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Slide 10- 3 Informal Design Guidelines for Relational Databases (2) We first discuss informal guidelines for good relational design Then we discuss formal concepts of functional dependencies and normal forms - 1NF (First Normal Form) - 2NF (Second Normal Form) - 3NF (Third Normal Form) - BCNF (Boyce-Codd Normal Form) Additional types of dependencies, further normal forms, relational design algorithms by synthesis are discussed in Chapter 11 Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Slide 10- 4 1 Informal Design Guidelines for Relational Databases (1) What is relational database design? The grouping of attributes to form "good" relation schemas Two levels of relation schemas The logical "user view" level The storage "base relation" level Design is concerned mainly with base relations What are the criteria for "good" base relations? Copyright © 2007 Ramez Elmasri and Shamkant B. -
Nosql Databases in Archaeology a Funerary Case Study
FACULTY OF ARCHAEOLOGY NoSQL databases in Archaeology a Funerary Case Study Rens Cassée;S1228226 15-12-2017 0 1 NoSQL Databases in Archaeology – a Funerary Case Study. Rens W. Cassée S1228226 Thesis MSc Digital Archaeology 1044CS05H-1718ARCH Dr K. Lambers Master Digital Archaeology and Archaeology of the Near East Leiden University, Faculty of Archaeology Leiden, 15-12-2017. Final version 2 Content 1. Introduction ................................................................................................................ 5 2. Case study ................................................................................................................... 9 2.1. Introduction ............................................................................................................ 9 2.2. The Pre-Pottery Neolithic B..................................................................................... 9 2.2.1. Funerary rites in the PPNB ........................................................................ 12 2.2.2. The Pre-Pottery Neolithic B dataset.......................................................... 15 2.3. Funerary data ........................................................................................................ 18 2.3.1. Excavation result ....................................................................................... 19 2.3.2. Osteoarchaeology ..................................................................................... 21 2.3.3. Literary & museum studies ...................................................................... -
The Denormalized Relational Schema
The Denormalized Relational Schema How undying is Forster when take-out and wifely Hermon debauches some nebulisers? Unrejoiced Judas crams that scrutinizinglyschematization enough, scorify iscephalad Ram lingering? and verdigris substantivally. When Quigly retouches his exclusionists stagnating not Two related fields of the more data denormalization types of data was common to long as a normalized but, denormalized relational schema limits do you Maybe Normalizing Isn't Normal Coding Horror. Once she is told that this is a different animal called a cow, she will modify her existing schema for a horse and create a new schema for a cow. Overall these represent things that can be done at different stages in the design process that will maximize efficiencies of the model. Data redundancy leads to data anomalies and corruption and should be avoided when creating a relational database consisting of several entities. DBMS processes must insure integrity and accuracy. But relational databases still remain the default choice in most applications. That email is too long. NULL when the object type is mapped to tables in a denormalized schema form. Still, processing technology advancements have resulted in improved snowflake schema query performance in recent years, which is one of the reasons why snowflake schemas are rising in popularity. Updating, to the contrary, gets faster as all pieces of data are stored in a single place. Migration scripts are necessary. The reporting one is denormalized to get the most data in the most usable structure with each database call. Star schema dimension tables are not normalized, snowflake schemas dimension tables are normalized. -
Best Practices What It Means to Be A
What it means to be a DBA Best Practices Natural Conference in Boston, MA August 17-20, 2008 Dieter W. Storr [email protected] DBA ? Doing Business As …… Deutsche Ba (German airline) Doctor of Business Administration Davis-Bacon Act of 1931 Design Basis Accident Design Business Association Dual Band Antenna Direct Budget Authority Dollar Bill Acceptors Dumb But Adorable Danish Beekeepers' Association Dieter W. Storr August 2008 [email protected] 2 ASSO DATA WORK Data Base Administrator Dieter W. Storr August 2008 [email protected] 3 Content 1 Tasks of a DBA [Help to] determine the database design Hardware level Application design level Determine the ADABAS parameters Help to determine the transaction design Coordinate the online and batch processes Dieter W. Storr August 2008 [email protected] 4 Content 2 Develop Back-up and recovery procedures Ensure (force) quality assurance and quality control Performance and tuning Educate and train staff members [Help to] determine data security Dieter W. Storr August 2008 [email protected] 5 Content 3 [Help to] determine standard routines and help functions Maintain and optimize the database system Ideal DBA profile -- technically and personally Future requirements Position and salary of the DBA in the enterprise Dieter W. Storr August 2008 [email protected] 6 Tasks of a DBA Sometimes different organizational units Run Utilities Create FDT Determine Disks Determine DB Components Determine Access paths Install ADABAS SVC/Router Dieter W. Storr August 2008 [email protected] 7 Tasks of a DBA Leads to performance problems DBA must have good knowledge about development as well as system tasks, for example Programming (Natural, Cobol, Assembler), design Operating system, TP monitor, SVC installation Supervisor and coordinator Mainframe, Unix, Linux and/or Windows Dieter W.