Dimensional Modeling Dimensional Modeling

ByBy

Divya ManduvaDivya Manduva

Pratima SurapaneniPratima Surapaneni

ContentsContents

Introduction to Dimensional ModelingIntroduction to Dimensional Modeling ER Vs Dimensional ModelingER Vs Dimensional Modeling CIF Relational ModelingCIF Relational Modeling Kimball’s Dimensional ModelingKimball’s Dimensional Modeling ComparisonComparison ConclusionConclusion DiscussionDiscussion

IntroductionIntroduction

Dimensional ModelingDimensional Modeling• Drill upDrill up• Slice and diceSlice and dice• Business Focused and AcceptedBusiness Focused and Accepted• Accessible InformationAccessible Information• Input for Decision SupportInput for Decision Support• Consistent PresentationConsistent Presentation

ER to Dimensional ModelingER to Dimensional Modeling• An IllustrationAn Illustration

Relational Vs Dimensional Relational Vs Dimensional

Relational Modeling Dimensional Modeling

Data is stored in RDBMS Data is stored in RDBMS or Multidimensional databases

Tables are units of storage Cubes are units of storage

Data is normalized and used for OLTP. Optimized for OLTP processing

Data is de normalized and used in data warehouse and data mart. Optimized for OLAP

Several tables and chains of relationships among them

Few tables and fact tables are connected to dimensional tables

Volatile (several updates) and time variant Non volatile and time invariant

Detailed level of transactional data Summary of bulky transactional data (Aggregates and Measures) used in business decisions

SQL is used to manipulate data MDX is used to manipulate data

Normal Reports User friendly, interactive, drag and drop multidimensional OLAP Reports

Corporate Information FactoryCorporate Information Factory

Kimball’s Dimensional Modeling ArchitectureKimball’s Dimensional Modeling Architecture

Dimensional TablesDimensional Tables

Represent objects of businessRepresent objects of business Contain text descriptions of businessContain text descriptions of business Small # of rows, Large # of columnsSmall # of rows, Large # of columns Serve as Primary source for “Query by”/ Serve as Primary source for “Query by”/

“Report by” constraints“Report by” constraints Highly De normalizedHighly De normalized Represent 10% of total dataRepresent 10% of total data Depth and Quality Determine Data Depth and Quality Determine Data

Warehouse Usefulness ( Level of Warehouse Usefulness ( Level of Granularity)Granularity)

SDLC Approach to Design a Data SDLC Approach to Design a Data WarehouseWarehouse

Compare and ContrastCompare and Contrast

Approach (Scope)Approach (Scope) PerspectivePerspective Data FlowData Flow Functionality/ FlexibilityFunctionality/ Flexibility ResultsResults

ConclusionConclusion

Suggesting a Hybrid ModelSuggesting a Hybrid Model

ReferencesReferences A method for developing Dimensional Data Marts, Tim Chenoweth, David A method for developing Dimensional Data Marts, Tim Chenoweth, David

Schuff, Robert St. Louis, Communications of ACM, Volume 46, Issue 12 Schuff, Robert St. Louis, Communications of ACM, Volume 46, Issue 12 December 2003December 2003

Dimensional Modeling: In a Business Intelligence Environment, Chuck Ballard, Dimensional Modeling: In a Business Intelligence Environment, Chuck Ballard, Daniel M. Farrell, Amit Gupta, Carlos Manuela, Stanislaw Venice Daniel M. Farrell, Amit Gupta, Carlos Manuela, Stanislaw Venice http://www.redbooks.ibm.com/redbooks/pdfs/sg247138.pdfhttp://www.redbooks.ibm.com/redbooks/pdfs/sg247138.pdf

IBM Informix Dynamic Server Enterprise and Workgroup Edition, v10.00.xC3; IBM Informix Dynamic Server Enterprise and Workgroup Edition, v10.00.xC3; IBM Informix Dynamic Server Express Edition, v10.00.xC3E; and IBM IBM Informix Dynamic Server Express Edition, v10.00.xC3E; and IBM Informix Client Software Developer's Kit, v2.90.xC3. Informix Client Software Developer's Kit, v2.90.xC3. http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.http://publib.boulder.ibm.com/infocenter/idshelp/v10/index.jsp?topic=/com.ibm.ddi.doc/ddi222.htmddi.doc/ddi222.htm

http://www.wilshireconferences.com/EDF2002/analytics-sessions.htmhttp://www.wilshireconferences.com/EDF2002/analytics-sessions.htm http://www.learndatamodeling.com/diff_r_d.htmhttp://www.learndatamodeling.com/diff_r_d.htm http://blogs.ittoolbox.com/dw/design/archives/dimensional-modeling-http://blogs.ittoolbox.com/dw/design/archives/dimensional-modeling-

fundamentals-7712fundamentals-7712

References (contd..)References (contd..) A method for developing Dimensional Data Marts, Tim Chenoweth, David Schuff, A method for developing Dimensional Data Marts, Tim Chenoweth, David Schuff,

Robert St. Louis, Communications of ACM December, Volume 46, Issue 12 2003Robert St. Louis, Communications of ACM December, Volume 46, Issue 12 2003 Mastering data warehouse design : relational and dimensional techniques / Claudia Mastering data warehouse design : relational and dimensional techniques / Claudia

Imhoff, Nicholas Galemmo, Jonathan G. Geiger Imhoff, Nicholas Galemmo, Jonathan G. Geiger http://http://search.barnesandnoble.com/booksearch/isbnInquiry.asp?zsearch.barnesandnoble.com/booksearch/isbnInquiry.asp?z==y&endecay&endeca=1&isbn=0471324213&itm=9=1&isbn=0471324213&itm=9

http://www.dbmsmag.com/9510d05.htmlhttp://www.dbmsmag.com/9510d05.html http://http://www.casact.org/newsletter/index.cfm?fawww.casact.org/newsletter/index.cfm?fa==viewart&idviewart&id=5349=5349 http://www.b-eye-network.com/view/410http://www.b-eye-network.com/view/410 http://http://www.dkms.com/papers/cifckf.pdfwww.dkms.com/papers/cifckf.pdf Daniel L. Moody, Mark A.R. Kortink, “Daniel L. Moody, Mark A.R. Kortink, “From Enterprise to Dimension Models: From Enterprise to Dimension Models:

A Methodology for Data Warehouse and Data Mart DesignA Methodology for Data Warehouse and Data Mart Design”, Proceedings of ”, Proceedings of the International Workshop on Design and Management of Data Warehouses the International Workshop on Design and Management of Data Warehouses (DMDW'2000), Stockholm, Sweden, June 5-6, 2000. (DMDW'2000), Stockholm, Sweden, June 5-6, 2000. (http://ssdi.di.fct.unl.pt/mei/bddw/material_apoio/artigos/files/2000-Moody.pdf) (http://ssdi.di.fct.unl.pt/mei/bddw/material_apoio/artigos/files/2000-Moody.pdf)

http://www.atlantamdf.com/Presentations/AtlantaMDF_091106.pdfhttp://www.atlantamdf.com/Presentations/AtlantaMDF_091106.pdf http://www.intelligententerprise.com/http://www.intelligententerprise.com/

showArticle.jhtml;jsessionid=NKBOH2L3S2BMMQSNDLRCKH0CJUNN2JVN?showArticle.jhtml;jsessionid=NKBOH2L3S2BMMQSNDLRCKH0CJUNN2JVN?articleID=17800088&pgno=2articleID=17800088&pgno=2

Dimensional Modeling: A whirlwind Tour of How and Why, Wayne Little, October 2006Dimensional Modeling: A whirlwind Tour of How and Why, Wayne Little, October 2006

DiscussionDiscussion

Thank you !Thank you !