introduction to mdx dustin ryan. a little bit about me… business intelligence consultant,...
TRANSCRIPT
Introduction To MDX
Dustin Ryan
A little bit about me… 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… Located in sunny, stupid hot Green
Cove Springs, FL Offer consulting and training services
Data Warehousing Data Migrations DTS Conversions
Software centering around Microsoft B.I. stack BI xPress
BIDS plugin for SSIS development BI Documenter
Document reports, packages, cubes, databases
Task Factory High performance SSIS tasks
What is MDX? Multi Dimensional eXpression
Language
Used to query cubes (multidimensional databases)
Developed during the late 1990’s
Where is MDX used? Cube calculations
KPI’s
Querying the cube
Why MDX? Allows complex reporting
Cube answers analytical questions
Data is pre-aggregated
DEMO
Useful Terminology Dimension
A Dimension organizes data in relation to a particular interest
Attribute Within a dimension are attributes. Attributes are
properties of the dimension that describe that area of interest.
Measures A measure can be summarized as a column that
contains some kind of quantifiable data that can be aggregated
More Useful Terminology Hierarchy
A user defined hierarchy is a hierarchical structure of attributes
A couple more terms… Level
Within a hierarchy are levels. An example of a level in the Date Hierarchy would be the Month Level.
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 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) Rows Columns Pages Chapters Sections
Most MDX queries contain only 2 axes since most reporting is done in a two dimensional tabular format
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 Tuples
A collection of dimension attributes not from the same dimension ex. ([Date].[Fiscal Year].members, [Sales Territory].[Sales Territory Country].members)
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 DEMO
DEMO
MDX Books to Check Out
MDX Solutions
Microsoft SQL Server 2008 MDX Step by Step
Practical MDX Queriesby Art Tennick
