introduction to mdx dustin ryan. a little bit about me… business intelligence consultant,...

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

Contact Me

Dustin Ryan Email:

dryan@pragmaticworks.com

Blog:

www.BIDN.com/blogs/DustinRyan