SlideShare a Scribd company logo
1 of 24
MULTIDIMENSIONAL DATA
MODEL
SUBMITTED BY-
JASBEER CHAUHAN,15071257
HARJINDER KHAN,15071258
SUBMITTED TO-
NEHA DOGRA
INTRODUCTION MDDM:-
• MDDM was Developed for implementing data
warehouse and data mart.
• It provide Both a mechanism to store Data and
a way for business analysis.
• It provide us interactive analysis of large
amount of data which help’s in decision
making process.
Why Multidimensional Database ?
Enables interactive analyses of large amounts
of data for decision-making purposes.
Rapidly process the data in the database so
that answers can be generated quickly.
Provides “just in time” information for
effective decision-making in a successful OLAP
application.
Enforces simplicity.
COMOPONENT OF MDDM:-
TYPES OF MDDM
• Data Cube Model
• Star Schema Model
• Snow flake Schema Model
• Fact constellations
Data Cube Dimensional
Model
• When data is combined together in
multidimensional matrices called Data Cubes.
• 2D-It consists of row and column or products
and fiscal quarters.
Conti..
• 3D- one regions , products and fiscal quarters.
Dimensions and measures
 Data cubes have categories of data called
dimensions and measures
 Measure- It represents some fact (number)
such as cost or units of service.
 Dimension- It represents descriptive
categories of data such as time or location.
Slicing, Dicing and Rotation
Slicing:
Refers to two – dimensional page selected
from the cube
Dicing :
Dicing provides you a smallest available slice.
It define a sub-cube of the original space.
Conti..
Slicing Dicing
Conti..
• Changing from one dimensional hierarchy to
another is early accomplished in data cube by
a technique called Rotation.
Conti..
• These types of models are applied to
hierarchical view such as Role up Display and
Drill Down Display.
Role up Display:-
 When role up operation is performed by dimension reduction
one or more dimension are remove from dimension cube.
 With role up capability user can zoom out to see a summarized level of
data.
 The navigation path is determined by hierarchy with in dimension,
Conti..
Drill-Down Display:-
 It is reverse of role up.
 it navigate from less detailed data to more detailed data.
 It can also be performs by adding new dimension to a cube.
STAR SCHEMA MODEL
• It is also known as star join schema
• It is simplest style of data warehouse schema.
• It is called Star Schema because the entity relationship
diagram of this schema resembles a star , with points
radiating from central table.
• A star query is a join between a fact table and a no of
dimension table.
• Each dimension table is joined to the fact table using
primary key to foreign key but dimension table not
joined to each other.
• A typical fact table consist of key and measure.
Conti..
Conti..
Advantage of Star Schema Model :-
Provide highly optimized performance for
typical star queries.
Provide a direct and intuitive mapping
between the business entities being analyzed
by end users.
SNOW FLAKE SCHEMA
It is slightly different from a star schema in
which the dimensional tables from a star
schema are organized into a hierarchy by
normalizing them.
The snow flake schema is represented by
centralized fact table which are connected to
multiple dimensions.
The snow flake effecting only affecting the
dimension table not the fact tables.
Conti..
Conti..
Benefits of Snow Flaking:-
I. It is easier to implement a snow flak schema
when a multidimensional is added to the
typically normalized tables.
II. A snow flake schema can reflect the same
data to the database.
Difference between snow flak schema and
star schema
Snow flak schema Star schema
No redundancy redundancy
More complex queries Less complex queries
Lots of foreign keys so it needed more
execution time.
Quick executions.
More no of dimensions for a single
dimension.
Only one dimension.
Normalized De-normalized
FACT CONSTELLATIONS:-
For each schema it is possible to construct fact
constellation table.
It limits the possible Queries for the data
warehouse.
The fact constellation architecture contains
multiple fact tables that share many
dimensional tables.
Conti..
 The main shortcoming of fact constellation schema is a more
complicated design because many variants of particular kinds
of aggregation must be considered and selected. Moreover,
dimensions tables are still large.
THANK
YOU

More Related Content

What's hot

What's hot (20)

multi dimensional data model
multi dimensional data modelmulti dimensional data model
multi dimensional data model
 
Multidimentional data model
Multidimentional data modelMultidimentional data model
Multidimentional data model
 
Data cube
Data cubeData cube
Data cube
 
Data Warehouse Designing: Dimensional Modelling and E-R Modelling
Data Warehouse Designing: Dimensional Modelling and E-R ModellingData Warehouse Designing: Dimensional Modelling and E-R Modelling
Data Warehouse Designing: Dimensional Modelling and E-R Modelling
 
Star schema PPT
Star schema PPTStar schema PPT
Star schema PPT
 
Difference between ER-Modeling and Dimensional Modeling
Difference between ER-Modeling and Dimensional ModelingDifference between ER-Modeling and Dimensional Modeling
Difference between ER-Modeling and Dimensional Modeling
 
Dimensional data model
Dimensional data modelDimensional data model
Dimensional data model
 
E-R vs Starschema
E-R vs StarschemaE-R vs Starschema
E-R vs Starschema
 
Steps To Build A Datawarehouse
Steps To Build A DatawarehouseSteps To Build A Datawarehouse
Steps To Build A Datawarehouse
 
Dimensional modelling-mod-3
Dimensional modelling-mod-3Dimensional modelling-mod-3
Dimensional modelling-mod-3
 
MSBI and Data WareHouse techniques by Quontra
MSBI and Data WareHouse techniques by Quontra MSBI and Data WareHouse techniques by Quontra
MSBI and Data WareHouse techniques by Quontra
 
Dw concepts
Dw conceptsDw concepts
Dw concepts
 
Dimensional data modeling
Dimensional data modelingDimensional data modeling
Dimensional data modeling
 
Star schema
Star schemaStar schema
Star schema
 
Advanced Dimensional Modelling
Advanced Dimensional ModellingAdvanced Dimensional Modelling
Advanced Dimensional Modelling
 
Dimensional Modelling Session 2
Dimensional Modelling Session 2Dimensional Modelling Session 2
Dimensional Modelling Session 2
 
Dimensional Modeling
Dimensional ModelingDimensional Modeling
Dimensional Modeling
 
Dimensional Modeling
Dimensional ModelingDimensional Modeling
Dimensional Modeling
 
Dbms schemas for decision support
Dbms schemas for decision supportDbms schemas for decision support
Dbms schemas for decision support
 
Introduction to Dimesional Modelling
Introduction to Dimesional ModellingIntroduction to Dimesional Modelling
Introduction to Dimesional Modelling
 

Similar to MULTIMEDIA MODELING

Data warehouse 20 star schema
Data warehouse 20 star schemaData warehouse 20 star schema
Data warehouse 20 star schemaVaibhav Khanna
 
Real-world BISM in SQL Server 2012 SSAS
Real-world BISM in SQL Server 2012 SSASReal-world BISM in SQL Server 2012 SSAS
Real-world BISM in SQL Server 2012 SSASLynn Langit
 
dataminingpres-150821063129-lva1-app6891 (3).pdf
dataminingpres-150821063129-lva1-app6891 (3).pdfdataminingpres-150821063129-lva1-app6891 (3).pdf
dataminingpres-150821063129-lva1-app6891 (3).pdfAnilGupta681764
 
Data warehouse 21 snowflake schema
Data warehouse 21 snowflake schemaData warehouse 21 snowflake schema
Data warehouse 21 snowflake schemaVaibhav Khanna
 
OLAP Cubes in Datawarehousing
OLAP Cubes in DatawarehousingOLAP Cubes in Datawarehousing
OLAP Cubes in DatawarehousingPrithwis Mukerjee
 
86921864 olap-case-study-vj
86921864 olap-case-study-vj86921864 olap-case-study-vj
86921864 olap-case-study-vjhomeworkping4
 
Multidimensional schema of data warehouse
Multidimensional schema of data warehouseMultidimensional schema of data warehouse
Multidimensional schema of data warehousekunjan shah
 
The final frontier v3
The final frontier v3The final frontier v3
The final frontier v3Terry Bunio
 
LECTURE 7.ppt.pdf
LECTURE 7.ppt.pdfLECTURE 7.ppt.pdf
LECTURE 7.ppt.pdfcikajen791
 
Lesson 3 - The Kimbal Lifecycle.pptx
Lesson 3 - The Kimbal Lifecycle.pptxLesson 3 - The Kimbal Lifecycle.pptx
Lesson 3 - The Kimbal Lifecycle.pptxcalf_ville86
 
The final frontier
The final frontierThe final frontier
The final frontierTerry Bunio
 
Data Warehouse approaches with Dynamics AX
Data Warehouse  approaches with Dynamics AXData Warehouse  approaches with Dynamics AX
Data Warehouse approaches with Dynamics AXAlvin You
 
Dimensional Modeling
Dimensional ModelingDimensional Modeling
Dimensional ModelingSunita Sahu
 

Similar to MULTIMEDIA MODELING (20)

Data warehouse 20 star schema
Data warehouse 20 star schemaData warehouse 20 star schema
Data warehouse 20 star schema
 
Real-world BISM in SQL Server 2012 SSAS
Real-world BISM in SQL Server 2012 SSASReal-world BISM in SQL Server 2012 SSAS
Real-world BISM in SQL Server 2012 SSAS
 
dataminingpres-150821063129-lva1-app6891 (3).pdf
dataminingpres-150821063129-lva1-app6891 (3).pdfdataminingpres-150821063129-lva1-app6891 (3).pdf
dataminingpres-150821063129-lva1-app6891 (3).pdf
 
Data warehouse 21 snowflake schema
Data warehouse 21 snowflake schemaData warehouse 21 snowflake schema
Data warehouse 21 snowflake schema
 
Business analysis
Business analysisBusiness analysis
Business analysis
 
OLAP Cubes in Datawarehousing
OLAP Cubes in DatawarehousingOLAP Cubes in Datawarehousing
OLAP Cubes in Datawarehousing
 
86921864 olap-case-study-vj
86921864 olap-case-study-vj86921864 olap-case-study-vj
86921864 olap-case-study-vj
 
Date Analysis .pdf
Date Analysis .pdfDate Analysis .pdf
Date Analysis .pdf
 
Multidimensional schema of data warehouse
Multidimensional schema of data warehouseMultidimensional schema of data warehouse
Multidimensional schema of data warehouse
 
The final frontier v3
The final frontier v3The final frontier v3
The final frontier v3
 
Complete unit ii notes
Complete unit ii notesComplete unit ii notes
Complete unit ii notes
 
Big Data Modeling
Big Data ModelingBig Data Modeling
Big Data Modeling
 
Data warehouse logical design
Data warehouse logical designData warehouse logical design
Data warehouse logical design
 
LECTURE 7.ppt.pdf
LECTURE 7.ppt.pdfLECTURE 7.ppt.pdf
LECTURE 7.ppt.pdf
 
NoSql Brownbag
NoSql BrownbagNoSql Brownbag
NoSql Brownbag
 
Lesson 3 - The Kimbal Lifecycle.pptx
Lesson 3 - The Kimbal Lifecycle.pptxLesson 3 - The Kimbal Lifecycle.pptx
Lesson 3 - The Kimbal Lifecycle.pptx
 
The final frontier
The final frontierThe final frontier
The final frontier
 
Data Warehouse approaches with Dynamics AX
Data Warehouse  approaches with Dynamics AXData Warehouse  approaches with Dynamics AX
Data Warehouse approaches with Dynamics AX
 
Sap Analytics Cloud
Sap Analytics CloudSap Analytics Cloud
Sap Analytics Cloud
 
Dimensional Modeling
Dimensional ModelingDimensional Modeling
Dimensional Modeling
 

Recently uploaded

Vip Female Escorts Noida 9711199171 Greater Noida Escorts Service
Vip Female Escorts Noida 9711199171 Greater Noida Escorts ServiceVip Female Escorts Noida 9711199171 Greater Noida Escorts Service
Vip Female Escorts Noida 9711199171 Greater Noida Escorts Serviceankitnayak356677
 
Call Girls in Gomti Nagar - 7388211116 - With room Service
Call Girls in Gomti Nagar - 7388211116  - With room ServiceCall Girls in Gomti Nagar - 7388211116  - With room Service
Call Girls in Gomti Nagar - 7388211116 - With room Servicediscovermytutordmt
 
Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...
Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...
Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...lizamodels9
 
Pharma Works Profile of Karan Communications
Pharma Works Profile of Karan CommunicationsPharma Works Profile of Karan Communications
Pharma Works Profile of Karan Communicationskarancommunications
 
Insurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usageInsurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usageMatteo Carbone
 
BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,noida100girls
 
VIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service Jamshedpur
VIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service JamshedpurVIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service Jamshedpur
VIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service JamshedpurSuhani Kapoor
 
Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.Eni
 
GD Birla and his contribution in management
GD Birla and his contribution in managementGD Birla and his contribution in management
GD Birla and his contribution in managementchhavia330
 
Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...
Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...
Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...Dipal Arora
 
Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝
Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝
Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝soniya singh
 
0183760ssssssssssssssssssssssssssss00101011 (27).pdf
0183760ssssssssssssssssssssssssssss00101011 (27).pdf0183760ssssssssssssssssssssssssssss00101011 (27).pdf
0183760ssssssssssssssssssssssssssss00101011 (27).pdfRenandantas16
 
Monte Carlo simulation : Simulation using MCSM
Monte Carlo simulation : Simulation using MCSMMonte Carlo simulation : Simulation using MCSM
Monte Carlo simulation : Simulation using MCSMRavindra Nath Shukla
 
7.pdf This presentation captures many uses and the significance of the number...
7.pdf This presentation captures many uses and the significance of the number...7.pdf This presentation captures many uses and the significance of the number...
7.pdf This presentation captures many uses and the significance of the number...Paul Menig
 
RE Capital's Visionary Leadership under Newman Leech
RE Capital's Visionary Leadership under Newman LeechRE Capital's Visionary Leadership under Newman Leech
RE Capital's Visionary Leadership under Newman LeechNewman George Leech
 
Grateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdfGrateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdfPaul Menig
 
BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,noida100girls
 
Call Girls In Panjim North Goa 9971646499 Genuine Service
Call Girls In Panjim North Goa 9971646499 Genuine ServiceCall Girls In Panjim North Goa 9971646499 Genuine Service
Call Girls In Panjim North Goa 9971646499 Genuine Serviceritikaroy0888
 
2024 Numerator Consumer Study of Cannabis Usage
2024 Numerator Consumer Study of Cannabis Usage2024 Numerator Consumer Study of Cannabis Usage
2024 Numerator Consumer Study of Cannabis UsageNeil Kimberley
 

Recently uploaded (20)

Vip Female Escorts Noida 9711199171 Greater Noida Escorts Service
Vip Female Escorts Noida 9711199171 Greater Noida Escorts ServiceVip Female Escorts Noida 9711199171 Greater Noida Escorts Service
Vip Female Escorts Noida 9711199171 Greater Noida Escorts Service
 
Call Girls in Gomti Nagar - 7388211116 - With room Service
Call Girls in Gomti Nagar - 7388211116  - With room ServiceCall Girls in Gomti Nagar - 7388211116  - With room Service
Call Girls in Gomti Nagar - 7388211116 - With room Service
 
Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...
Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...
Lowrate Call Girls In Laxmi Nagar Delhi ❤️8860477959 Escorts 100% Genuine Ser...
 
Pharma Works Profile of Karan Communications
Pharma Works Profile of Karan CommunicationsPharma Works Profile of Karan Communications
Pharma Works Profile of Karan Communications
 
Insurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usageInsurers' journeys to build a mastery in the IoT usage
Insurers' journeys to build a mastery in the IoT usage
 
BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Greater Noida ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
 
VIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service Jamshedpur
VIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service JamshedpurVIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service Jamshedpur
VIP Call Girl Jamshedpur Aashi 8250192130 Independent Escort Service Jamshedpur
 
Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.Eni 2024 1Q Results - 24.04.24 business.
Eni 2024 1Q Results - 24.04.24 business.
 
Forklift Operations: Safety through Cartoons
Forklift Operations: Safety through CartoonsForklift Operations: Safety through Cartoons
Forklift Operations: Safety through Cartoons
 
GD Birla and his contribution in management
GD Birla and his contribution in managementGD Birla and his contribution in management
GD Birla and his contribution in management
 
Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...
Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...
Call Girls Navi Mumbai Just Call 9907093804 Top Class Call Girl Service Avail...
 
Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝
Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝
Call Girls in Mehrauli Delhi 💯Call Us 🔝8264348440🔝
 
0183760ssssssssssssssssssssssssssss00101011 (27).pdf
0183760ssssssssssssssssssssssssssss00101011 (27).pdf0183760ssssssssssssssssssssssssssss00101011 (27).pdf
0183760ssssssssssssssssssssssssssss00101011 (27).pdf
 
Monte Carlo simulation : Simulation using MCSM
Monte Carlo simulation : Simulation using MCSMMonte Carlo simulation : Simulation using MCSM
Monte Carlo simulation : Simulation using MCSM
 
7.pdf This presentation captures many uses and the significance of the number...
7.pdf This presentation captures many uses and the significance of the number...7.pdf This presentation captures many uses and the significance of the number...
7.pdf This presentation captures many uses and the significance of the number...
 
RE Capital's Visionary Leadership under Newman Leech
RE Capital's Visionary Leadership under Newman LeechRE Capital's Visionary Leadership under Newman Leech
RE Capital's Visionary Leadership under Newman Leech
 
Grateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdfGrateful 7 speech thanking everyone that has helped.pdf
Grateful 7 speech thanking everyone that has helped.pdf
 
BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
BEST Call Girls In Old Faridabad ✨ 9773824855 ✨ Escorts Service In Delhi Ncr,
 
Call Girls In Panjim North Goa 9971646499 Genuine Service
Call Girls In Panjim North Goa 9971646499 Genuine ServiceCall Girls In Panjim North Goa 9971646499 Genuine Service
Call Girls In Panjim North Goa 9971646499 Genuine Service
 
2024 Numerator Consumer Study of Cannabis Usage
2024 Numerator Consumer Study of Cannabis Usage2024 Numerator Consumer Study of Cannabis Usage
2024 Numerator Consumer Study of Cannabis Usage
 

MULTIMEDIA MODELING

  • 1. MULTIDIMENSIONAL DATA MODEL SUBMITTED BY- JASBEER CHAUHAN,15071257 HARJINDER KHAN,15071258 SUBMITTED TO- NEHA DOGRA
  • 2. INTRODUCTION MDDM:- • MDDM was Developed for implementing data warehouse and data mart. • It provide Both a mechanism to store Data and a way for business analysis. • It provide us interactive analysis of large amount of data which help’s in decision making process.
  • 3. Why Multidimensional Database ? Enables interactive analyses of large amounts of data for decision-making purposes. Rapidly process the data in the database so that answers can be generated quickly. Provides “just in time” information for effective decision-making in a successful OLAP application. Enforces simplicity.
  • 5. TYPES OF MDDM • Data Cube Model • Star Schema Model • Snow flake Schema Model • Fact constellations
  • 6. Data Cube Dimensional Model • When data is combined together in multidimensional matrices called Data Cubes. • 2D-It consists of row and column or products and fiscal quarters.
  • 7. Conti.. • 3D- one regions , products and fiscal quarters.
  • 8. Dimensions and measures  Data cubes have categories of data called dimensions and measures  Measure- It represents some fact (number) such as cost or units of service.  Dimension- It represents descriptive categories of data such as time or location.
  • 9.
  • 10. Slicing, Dicing and Rotation Slicing: Refers to two – dimensional page selected from the cube Dicing : Dicing provides you a smallest available slice. It define a sub-cube of the original space.
  • 12. Conti.. • Changing from one dimensional hierarchy to another is early accomplished in data cube by a technique called Rotation.
  • 13. Conti.. • These types of models are applied to hierarchical view such as Role up Display and Drill Down Display. Role up Display:-  When role up operation is performed by dimension reduction one or more dimension are remove from dimension cube.  With role up capability user can zoom out to see a summarized level of data.  The navigation path is determined by hierarchy with in dimension,
  • 14. Conti.. Drill-Down Display:-  It is reverse of role up.  it navigate from less detailed data to more detailed data.  It can also be performs by adding new dimension to a cube.
  • 15. STAR SCHEMA MODEL • It is also known as star join schema • It is simplest style of data warehouse schema. • It is called Star Schema because the entity relationship diagram of this schema resembles a star , with points radiating from central table. • A star query is a join between a fact table and a no of dimension table. • Each dimension table is joined to the fact table using primary key to foreign key but dimension table not joined to each other. • A typical fact table consist of key and measure.
  • 17. Conti.. Advantage of Star Schema Model :- Provide highly optimized performance for typical star queries. Provide a direct and intuitive mapping between the business entities being analyzed by end users.
  • 18. SNOW FLAKE SCHEMA It is slightly different from a star schema in which the dimensional tables from a star schema are organized into a hierarchy by normalizing them. The snow flake schema is represented by centralized fact table which are connected to multiple dimensions. The snow flake effecting only affecting the dimension table not the fact tables.
  • 20. Conti.. Benefits of Snow Flaking:- I. It is easier to implement a snow flak schema when a multidimensional is added to the typically normalized tables. II. A snow flake schema can reflect the same data to the database.
  • 21. Difference between snow flak schema and star schema Snow flak schema Star schema No redundancy redundancy More complex queries Less complex queries Lots of foreign keys so it needed more execution time. Quick executions. More no of dimensions for a single dimension. Only one dimension. Normalized De-normalized
  • 22. FACT CONSTELLATIONS:- For each schema it is possible to construct fact constellation table. It limits the possible Queries for the data warehouse. The fact constellation architecture contains multiple fact tables that share many dimensional tables.
  • 23. Conti..  The main shortcoming of fact constellation schema is a more complicated design because many variants of particular kinds of aggregation must be considered and selected. Moreover, dimensions tables are still large.