The document introduces Data Vault modeling as an agile approach to data warehousing. It discusses how Data Vault addresses some limitations of traditional dimensional modeling by allowing for more flexible, adaptable designs. The Data Vault model consists of three simple structures - hubs, links, and satellites. Hubs contain unique business keys, links represent relationships between keys, and satellites hold descriptive attributes. This structure supports incremental development and rapid changes to meet evolving business needs in an agile manner.
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Agile Data Warehouse Modeling: Introduction to Data Vault Data Modeling
1. Agile Data Warehouse Modeling:
Introduction to Data Vault Modeling
Kent Graziano
Data Warrior LLC
Twitter @KentGraziano
2. Agenda
Bio
What do we mean by Agile?
What is a Data Vault?
Where does it fit in an DW/BI architecture
How to design a Data Vault model
Being “agile”
#OUGF14
3. My Bio
Oracle ACE Director
Certified Data Vault Master and DV 2.0 Architect
Member: Boulder BI Brain Trust
Data Architecture and Data Warehouse Specialist
● 30+ years in IT
● 25+ years of Oracle-related work
● 20+ years of data warehousing experience
Co-Author of
● The Business of Data Vault Modeling
● The Data Model Resource Book (1st Edition)
Past-President of ODTUG and Rocky Mountain Oracle
User Group
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4. Manifesto for Agile Software Development
“We are uncovering better ways of developing
software by doing it and helping others do it.
Through this work we have come to value:
Individuals and interactions over processes and
tools
Working software over comprehensive
documentation
Customer collaboration over contract negotiation
Responding to change over following a plan
That is, while there is value in the items on the right,
we value the items on the left more.”
http://agilemanifesto.org/
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5. Applying the Agile Manifesto to DW
User Stories instead of
requirements documents
Time-boxed iterations
● Iteration has a standard length
● Choose one or more user stories to fit in that
iteration
Rework is part of the game
● There are no “missed requirements”... only
those that haven’t been delivered or
discovered yet.
(C) Kent Graziano
#OUGF14
6. Data Vault Definition
The Data Vault is a detail oriented, historical tracking
and uniquely linked set of normalized tables that
support one or more functional areas of business.
It is a hybrid approach encompassing the best of
breed between 3rd normal form (3NF) and star
schema. The design is flexible, scalable, consistent
and adaptable to the needs of the enterprise.
Dan Linstedt: Defining the Data Vault
TDAN.com Article
Architected specifically to meet the needs
of today’s enterprise data warehouses
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7. What is Data Vault Trying to Solve?
What are our other Enterprise
Data Warehouse options?
● Third-Normal Form (3NF): Complex
primary keys (PK’s) with cascading
snapshot dates
● Star Schema (Dimensional): Difficult to
reengineer fact tables for granularity
changes
Difficult to get it right the first
time
Not adaptable to rapid
business change
NOT AGILE!
(C) Kent Graziano
#OUGF14
8. Data Vault Time Line
20001960 1970 1980 1990
E.F. Codd invented
relational modeling
Chris Date and
Hugh Darwen
Maintained and
Refined
Modeling
1976 Dr Peter Chen
Created E-R
Diagramming
Early 70’s Bill
Inmon Began
Discussing Data
Warehousing
Mid 60’s Dimension & Fact
Modeling presented by
General Mills and Dartmouth
University
Mid 70’s AC Nielsen
Popularized
Dimension & Fact Terms
Mid – Late 80’s Dr Kimball
Popularizes Star Schema
Mid 80’s Bill Inmon
Popularizes Data
Warehousing
Late 80’s – Barry
Devlin and Dr Kimball
Release “Business
Data Warehouse”
1990 – Dan Linstedt
Begins R&D on Data
Vault Modeling
2000 – Dan Linstedt
releases first 5
articles on Data Vault
Modeling
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9. Data Vault Evolution
The work on the Data Vault approach began in the
early 1990s, and completed around 1999.
Throughout 1999, 2000, and 2001, the Data Vault
design was tested, refined, and deployed into specific
customer sites.
In 2002, the industry thought leaders were asked to
review the architecture.
● This is when I attend my first DV seminar in Denver and met
Dan!
In 2003, Dan began teaching the modeling techniques
to the mass public.
Now in 2014, Dan introduced DV 2.0!
(C) Kent Graziano
#OUGF14
12. How to be Agile using DV
Model iteratively
● Use Data Vault data modeling technique
● Create basic components, then add over time
Virtualize the Access Layer
● Don’t waste time building facts and dimensions up front
● ETL and testing takes too long
● “Project” objects using pattern-based DV model with
database views (or BI meta layer)
Users see real reports with real data
Can always build out for performance in
another iteration
(C) Kent Graziano
#OUGF14
16. 1. Hub = Business Keys
Hubs = Unique Lists of Business Keys
Business Keys are used to
TRACK and IDENTIFY key information
New: DV 2.0 includes MD5 of the BK to
link to Hadoop/NoSQL
(C) Kent Graziano #OUGF14
17. 2: Links = Associations
Links =
Transactions and
Associations
They are used to
hook together
multiple sets of
information
In DV 2.0 the BK
attributes migrate
to the Links for
faster query
(C) Kent Graziano
#OUGF14
18. Modeling Links - 1:1 or 1:M?
Today:
● Relationship is a 1:1 so why model a Link?
Tomorrow:
● The business rule can change to a 1:M.
● You discover new data later.
With a Link in the Data Vault:
● No need to change the EDW structure.
● Existing data is fine.
● New data is added.
(C) Kent Graziano
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19. 3. Satellites = Descriptors
•Satellites provide
context for the
Hubs and the
Links
•Tracks changes
over time
•Like SCD 2
(C) Kent Graziano
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21. Data Vault Model Flexibility (Agility)
Goes beyond standard 3NF
• Hyper normalized
● Hubs and Links only hold keys and meta data
● Satellites split by rate of change and/or source
• Enables Agile data modeling
● Easy to add to model without having to change existing
structures and load routines
• Relationships (links) can be dropped and created on-demand.
● No more reloading history because of a missed requirement
Based on natural business keys
• Not system surrogate keys
• Allows for integrating data across functions and source
systems more easily
● All data relationships are key driven.
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22. Data Vault Extensibility
Adding new components to
the EDW has NEAR ZERO
impact to:
• Existing Loading
Processes
• Existing Data Model
• Existing Reporting & BI
Functions
• Existing Source Systems
• Existing Star Schemas
and Data Marts
(C) LearnDataVault.com #OUGF14
23. Standardized modeling rules
• Highly repeatable and learnable modeling technique
• Can standardize load routines
● Delta Driven process
● Re-startable, consistent loading patterns.
• Can standardize extract routines
● Rapid build of new or revised Data Marts
• Can be automated
‣ Can use a BI-meta layer to virtualize the reporting
structures
‣ Example: OBIEE Business Model and Mapping tool
‣ Example: BOBJ Universe Business Layer
‣ Can put views on the DV structures as well
‣ Simulate ODS/3NF or Star Schemas
Data Vault Productivity
(C) Kent Graziano
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24. • The Data Vault holds granular historical
relationships.
• Holds all history for all time, allowing any
source system feeds to be reconstructed on-
demand
• Easy generation of Audit Trails for data lineage
and compliance.
• Data Mining can discover new relationships
between elements
• Patterns of change emerge from the historical
pictures and linkages.
• The Data Vault can be accessed by power-users
Data Vault Adaptability
(C) Kent Graziano
#OUGF14
25. Other Benefits of a Data Vault
Modeling it as a DV forces integration of the Business Keys
upfront.
• Good for organizational alignment.
An integrated data set with raw data extends it’s value beyond BI:
• Source for data quality projects
• Source for master data
• Source for data mining
• Source for Data as a Service (DaaS) in an SOA (Service Oriented Architecture).
Upfront Hub integration simplifies the data integration routines
required to load data marts.
• Helps divide the work a bit.
It is much easier to implement security on these granular pieces.
Granular, re-startable processes enable pin-point failure
correction.
It is designed and optimized for real-time loading in its core
architecture (without any tweaks or mods).
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27. Worlds Smallest Data Vault
The Data Vault doesn’t have to be
“BIG”.
An Data Vault can be built
incrementally.
Reverse engineering one component
of the existing models is not
uncommon.
Building one part of the Data Vault,
then changing the marts to feed from
that vault is a best practice.
The smallest Enterprise Data
Warehouse consists of two tables:
● One Hub,
● One Satellite
Hub_Cust_Seq_ID
Hub_Cust_Num
Hub_Cust_Load_DTS
Hub_Cust_Rec_Src
Hub Customer
Hub_Cust_Seq_ID
Sat_Cust_Load_DTS
Sat_Cust_Load_End_DTS
Sat_Cust_Name
Sat_Cust_Rec_Src
Satellite Customer Name
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28. Notably…
In 2008 Bill Inmon stated that the “Data Vault
is the optimal approach for modeling the EDW
in the DW2.0 framework.” (DW2.0)
The number of Data Vault users in the US
surpassed 500 in 2010 and grows rapidly
(http://danlinstedt.com/about/dv-customers/)
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29. Organizations using Data Vault
WebMD Health Services
Anthem Blue-Cross Blue Shield
MD Anderson Cancer Center
Denver Public Schools
Independent Purchasing Cooperative (IPC, Miami)
• Owner of Subway
Kaplan
US Defense Department
Colorado Springs Utilities
State Court of Wyoming
Federal Express
US Dept. Of Agriculture
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32. Summary
• Data Vault provides a data
modeling technique that
allows:
‣ Model Agility
‣ Enabling rapid changes and additions
‣ Productivity
‣ Enabling low complexity systems with high
value output at a rapid pace
‣ Easy projections of dimensional models
‣ So? Agile Data Warehousing?
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33. Super Charge Your Data Warehouse
Available on Amazon.com
Soft Cover or Kindle Format
Now also available in PDF at
LearnDataVault.com
Hint: Kent is the Technical
Editor
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