Introduction To MDX
Dustin Ryan

A little bit about me…
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Business Intelligence Consultant,
Pragmatic Works
Technical editor for the many authors at
Pragmatic Works
Blog/Write @ www.BIDN.com
Proficient in magic
Part-time belly dancer at I-4 truck stop

About Pragmatic Works…
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Located in sunny, stupid hot Green
Cove Springs, FL
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Offer consulting and training services
Data Warehousing
Data Migrations
DTS Conversions
Software centering around Microsoft
B.I. stack
BI xPress
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BIDS plugin for SSIS development
BI Documenter
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Document reports, packages, cubes, databases
Task Factory
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High performance SSIS tasks

What is MDX?
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Multi Dimensional eXpression Language
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Used to query cubes
(multidimensional databases)
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Developed during the late 1990’s

Where is MDX used?
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Cube calculations
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KPI’s
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Querying the cube

Why MDX?
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Allows complex reporting
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Cube answers analytical questions
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Data is pre-aggregated
DEMO

Useful Terminology
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Dimension
A Dimension organizes data in relation to a particular interest
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Attribute
Within a dimension are attributes. Attributes are properties of the dimension that describe that area of interest.
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Measures
A measure can be summarized as a column that contains some kind of quantifiable data that can be aggregated

More Useful Terminology
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Hierarchy
A user defined hierarchy is a hierarchical structure of attributes

A couple more terms…
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Level
Within a hierarchy are levels. An example of a level in the Date
Hierarchy would be the Month Level.
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Member
A member is a value of a level. An example of a member of the
Month level would be March or April.

Yet More Useful Terms
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Axis
Can be thought of as the line on a which a single dimension rests which intersects our measure groups
An MDX query can have up to 128 axes (only 5 are aliased)
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Rows
Columns
Pages
Chapters
Sections
Most MDX queries contain only 2 axes since most reporting is done in a two dimensional tabular format

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Basic MDX Query Syntax
MDX Query example:
Select [Date].[Fiscal Year].members on Rows ,
[Measures].[Internet Order Quantity] on Columns
From [Adventure Works]
Where [Product].[Category].&[1]
DEMO

Tuples & Sets
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Tuples
A collection of dimension attributes not from the same dimension ex. ( [Date].[Fiscal Year].members, [Sales Territory].[Sales
Territory Country].members
)
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Set
A collection of tuples ex. { ( [Date].[Fiscal Year].&[2006], [Sales Reason].[Sales
Reason].&[9] ) , ( [Date].[Fiscal Year].&[2006], [Sales
Reason].[Sales Reason].&[5] ) }
DEMO

Common MDX Calculations
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DEMO
DEMO

MDX Books to Check Out
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MDX Solutions
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Microsoft SQL Server 2008 MDX
Step by Step
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Practical MDX Queries by Art Tennick

Contact Me
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Dustin Ryan
Email: dryan@pragmaticworks.com
 Blog: www.BIDN.com/blogs/DustinRyan