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Cubes for Flat Table Land Michael P. Antonovich #SharePointMikeA.

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Presentation on theme: "Cubes for Flat Table Land Michael P. Antonovich #SharePointMikeA."— Presentation transcript:

1 Cubes for Flat Table Land Michael P. Antonovich #SharePointMikeA

2 My Published Books Users Guide to the Apple ][ FoxPro 2 Programming Guide – 1992 Debugging and Maintaining FoxPro – 1992 Using Visual FoxPro 3.0 – 1995 Using Visual FoxPro 5.0 – 1996 Office and SharePoint Users Guide – 2007 Office and SharePoint Users Guide – 2010 October 24, 2012OPASS Mtg Speaker at: Code Camp 2009, 2010, 2011, 2012 Orlando SharePoint Saturday 2011 & 2012 Tampa, 2012 Orlando SQL Saturday - #1, #4, #8, #10, #15, #16, #21, #32, #38, #49, #62, #74, #79, #85, #86, #110, #130, #151, #168 IT PRCamp – Jacksonville

3 IMPORTANT BI TERMS Aggregate A mathematical function that allows you to summarize values of an attribute Dimension A dimension is essentially a look-up table that may define a hierarchy or drill-down path such as Year > Quarter > Month MeasureA measure is something that identifies a value Fact A fact is another term for a measure that contains numeric data that can be grouped along one or more dimensional hierarchy Star Schema All dimension tables radiate out from a single fact table Snowflake Schema One fact table may relate to another fact table before relating to dimension tables. One dimension table can also have a related dimension table A Pivot table or chart is usually based around a single fact table Some Basic BI Terminology October 24, 2012OPASS Mtg3

4 Two Models in SSAS Multidimensional Model No major functionality changes since 2008 R2 Tabular Model Visually and functionally resembles PowerPivot 2012 Both can be installed as separate instances on the same server. October 24, 2012OPASS Mtg4

5 Advantages of the MultiDimensional Model Tested technology since SQL 2000 Pre-calculated aggregates provide performance enhancements. Can handle larger data since it can store data on disk (MOLAP) or directly query the relational data source (ROLAP) Uses MDX which is supported by many 3 rd party client tools. October 24, 2012OPASS Mtg5

6 Disadvantages of the MultiDimensional Model Model is getting old and is not being revised. (designed for 32 bit, row based data and disk storage). MDX is perceived as being difficult to learn. Processing a multidimensional model can result in substantial downtime for large models. Changes to one table require the entire model to be reprocessed. Not compatible with PowerPivot October 24, 2012OPASS Mtg6

7 Advantages of the Tabular Model A 100% memory-based model provides greater performance. The xVelocity analytics column based engine offers significant query performance improvements. Queries and formulas use DAX which is easier to learn than MDX. (MDX is also supported) Queries data from many different data sources. October 24, 2012OPASS Mtg7

8 Disadvantages of the Tabular Model Does not support many-to-many relationships. Does not support true role-playing dimensions. Does not support cell-level security. Does not support security on measures. Does not support translations of metadata for locales. Does not support ragged hierarchies. October 24, 2012OPASS Mtg8

9 Which to Choose? For most applications (60-70%) either model will work. Do you currently have a model in Multidimensional mode? Are you just learning Analysis Services? Licensing issues? Compatibility with PowerPivot? Hardware? Performance Issues? October 24, 2012OPASS Mtg9

10 SSAS Tabular Uses DAX Data Analysis Expressions DAX is used to: Create calculated columns Create custom measures DAX Stands for October 24, 2012OPASS Mtg10

11 Basic Syntax DAX expressions always begin with an equal sign: = Column References can be qualified or unqualified TableName[ColumnName][ColumnName] Integer Real Currency Date(DateTime) TRUE/FALSE (Boolean) Text DAX Data TypesDAX Operators +, - *, / =, <> >,< >=, <= & AND&& OR|| NOT! October 24, 2012OPASS Mtg11

12 DAX Functions 2010 Version consisted of 135 functions 71 functions are similar to Excel functions 69 have the same name – 2 do not TEXT FORMAT DATEDIF YEARFRAC 64 functions are unique to DAX Aggregate data functions Date related functions 2012 Version has a little over 170 functions (no, I will not cover them all today) October 24, 2012OPASS Mtg12

13 Types of DAX Calculations Simple Calculations Calculated columns within fact tables Calculated columns for dimension tables Calculated columns between tables Calculated columns to eliminate lookup tables Calculated columns to serve as links to tables using multiple columns (Calculated columns are calculated for every row in the table) Context is the row Aggregate Calculations Calculate unique measures Context is in the evaluation of the pivot data (Aggregate measures are only calculated for the displayed data in the Pivot table) October 24, 2012OPASS Mtg13

14 Tabular Model Can Import From Microsoft Access 2003, 2007, 2010 Microsoft SQL Server 2005, 2008, 2008 R2 Oracle Relational DB 9i, 10g, 11g Teradata V2R6, V12 IBM Relational Database 8.1 Sybase Relational Databases October 24, 2012OPASS Mtg Many other ODBC Databases Text files (.txt,.tab,.csv) Analysis Services Cubes from SQL Server Data Feeds using Atom 1.0 Format Excel Files from , 2007,

15 Demo 1a: Retrieve Data from Multiple Sources October 24, 2012OPASS Mtg Open C:\Contoso2012\Stores.xlsx and rename to C:\Contoso2012\SQLSaturday1.xlsx Open C:\Contoso2012\Stores.xlsx and rename to C:\Contoso2012\SQLSaturday1.xlsx Go to PowerPivot window and load SQL Server database: Contoso2012 using all tables Go to PowerPivot window and load SQL Server database: Contoso2012 using all tables Add to Data Model, Stores from the current spreadsheet. This is a linked table. Add to Data Model, Stores from the current spreadsheet. This is a linked table. Add Access database ProductCategories. Add Access database ProductCategories. Add Excel file: Geography.xlsx Add Excel file: Geography.xlsx 15

16 Demo 1a: Load Data October 24, 2012OPASS Mtg16

17 Loading Data into the Tabular Model Demo October 24, 2012OPASS Mtg17

18 Demo 1b: Create Relationships October 24, 2012OPASS Mtg18

19 Demo 1c: Show Diagram View October 24, 2012OPASS Mtg19

20 Creating Relations Between Tables Demo October 24, 2012OPASS Mtg20

21 Technical vs. Useless Columns Technical Columns Used to link tables (IDs) Use to calculate other columns Hide from Pivot Table Field List Useless Columns Came in when data imported from data source Not used in pivot table or to link tables Delete to improve performance October 24, 2012OPASS Mtg21

22 Demo 2: Eliminate Useless Columns and Hide Technical Columns October 24, 2012OPASS Mtg22

23 Denormalize Data Model Eliminate tables and columns that are not going to be used. Flatten structure by created calculated dimension attributes based on values in other tables. Hide columns used in calculations but which users no longer need to see. October 24, 2012OPASS Mtg23

24 Create a Hierarchy Predefine common hierarchies for users Hierarchies are defined from the largest grouping to the smallest: Product Category Product Subcategory Product After defining the hierarchy, you can remove the individual columns used to define the hierarchy. October 24, 2012OPASS Mtg24

25 Demo 3: Define a Product Hierarchy October 24, 2012OPASS Mtg25

26 Demo 4: Demo of Cube (so far) Using Excel Pivot October 24, 2012OPASS Mtg26

27 Building Hierarchies Demo October 24, 2012OPASS Mtg27

28 Create a Calculated Measure For those times when a built-in measure just isnt enough… …you need a custom measure creating using DAX to satisfy the need. What is new in 2012 is that calculated measures can now be defined in the calculation area of the fact table. October 24, 2012OPASS Mtg28

29 Creating Custom DAX Measures For example, suppose you want to display the percent increase or decrease in sales by product in your stores channel for this year vs last year. You need a new measure to calculate store sales: StoreSales:=CALCULATE(SUM([SalesAmount]),DimChannel[Ch annelName]="Store") By default, the above calculates sales for the entire table. However, in the pivot table, we can use the dimension: YEAR as a filter or slicer to perform the calculation by each year in the table. October 24, 2012OPASS Mtg29

30 Dimensions Serve as Filters Use Time Functions to calculate measures for other time periods. LastYrSales:=CALCULATE([StoreSales], DATEADD(DimDate[Datekey],-1,year)) DATEADD(DimDate[Datekey],-1,year)) The above expression allows us to reference an existing expression but apply an additional filter to the calculation of StoreSales (which is already filtering on the channel: store). That additional filter in this case calculates the Store sales for the date one year prior to the current date of the record. October 24, 2012OPASS Mtg30

31 Calculate the Percent Change in Sales Given the prior two calculated measures, store sales for the current year and store sales for the prior year for each period in the cube, you can now calculate the percent change using an expression like: YearlyGrowth:=([StoreSales]-[LastYrSales])/[LastYrSales] October 24, 2012OPASS Mtg31

32 Using Error Checking Actually, the above sample works only because the slicer limited the calculations to specific years. However, in general, you need to check equations for error conditions like dividing by zero by using a formula more like: YearlyGrowth:=IF(ISBLANK([StoreSales]) || ISBLANK([LastYrSales]), 0, ([StoreSales]- [LastYrSales])/[LastYrSales]) October 24, 2012OPASS Mtg32

33 Demo 5a: Define a Calculated Measure October 24, 2012OPASS Mtg33

34 Demo 5b: The Pivot Table with Calculated Measures October 24, 2012OPASS Mtg34

35 Turning a Calculated Measure into a KPI KPI are nothing more than calculated measures in a fact table that are compared to a target value to determine whether the value is good or bad. October 24, 2012OPASS Mtg35

36 Adding KPI Calculations What is a KPI? Key Performance Indicator Key Performance Indicators provide information at a glance to indicate status of a measureable fact about your company/organization October 24, 2012OPASS Mtg36

37 Adding KPI Calculations A KPI Needs: A Base Value A Base Value A Target Value A Target Value A number of status intervals A number of status intervals Thresholds for each interval Thresholds for each interval Symbols to use to indicate status Symbols to use to indicate status October 24, 2012OPASS Mtg37

38 Demo 6a: Using DAX to Create a KPI October 24, 2012OPASS Mtg38

39 Demo 6b: Using DAX to Create a KPI October 24, 2012OPASS Mtg39

40 Adding a KPI Demo October 24, 2012OPASS Mtg40

41 Sorting by Other Fields You notice in the previous demo that while the rows displayed the sales by month, the months were sorted alphabetically, not chronologically. No one will accept that. How can you sort the months correctly. PowerPivot 2012 introduces a Sort by Another Column feature! October 24, 2012OPASS Mtg41

42 Define a Calculated Column with the Month # October 24, 2012OPASS Mtg42

43 Associate the Month Label with the New Column October 24, 2012OPASS Mtg43

44 Demo 6c: Correctly Ordered Months October 24, 2012OPASS Mtg44

45 Sorting on Alternate Columns Demo October 24, 2012OPASS Mtg45

46 Useful Links My blog is running a series of articles on working with the Tabular model Using the SSAS Tabular Model Week 1 Gathering Data From Different Data Sources Week 2 Displaying your first Pivot Table from a Tabular Model Hierarchies KPIs Clean-Up in Week 7 DAX On-line Function Reference October 24, 2012OPASS Mtg46

47 October 24, 2012OPASS Mtg47

48 Thank You October 24, 2012OPASS Mtg48

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