Ranking in BusinessObjects Reports

Ranking in BusinessObjects Reports

Ranking in BusinessObjects Reports

Maja Ferle, SRC.SI

Copyright © 2004 Business Objects S.A. All rights reserved.Slide 3

Topics

Introduction

Simple ranking

Ranking top (n) using variables

Ranking with a database analytical function

Cumulative percentage

Q&A


Introduction

About the speaker Business Intelligence Consultant, SRC.SI, Slovenia 9+ years of BI experience Member of BOB

Business intelligence solutions using BusinessObjects Banking Manufacturing Telecommunications

Different industries but same types of user requirements Most profitable customers (products) Top (n) customers (products) Revenue by cumulative percentage


Topics

Introduction

Simple ranking




Q&A


Simple Ranking 1/5

Modified Island Resorts marketing universe Added more data to the database

Sample report #1 Number of guests by country of resort Display the top 3 countries

Step 1: Create the report Use objects Country and Number of guests

Illustration of simple ranking techniques


Simple Ranking 2/5

Step 2: Apply ranking Ranking is always performed on a dimension based on a measure Use the ranking toolbar button or choose Format Ranking

from the menu Enter Top 3

Based on Number of guests


Simple Ranking 3/5

Result

Step 3: Display the rank order Use the rank() function Add a new column to the table Enter the formula

=Rank(<Country> ,<Number of guests>)


Simple Ranking 4/5

Result

Change the report: Display the top 5 countries Choose Format Ranking from the menu Do not use the ranking toolbar button again because it will undo

the previous ranking settings Enter Top 5 Based on Number of guests


Simple Ranking 5/5

Result

The challenge: Ranking top (n) Users of InfoView do not have the ranking capability End-users may not know how to apply ranking Users want to enter the value of n as a response to a prompt when

refreshing the report


Topics

Introduction

Simple ranking




Q&A


Ranking Top (n) Using Variables 1/10

Two ways of prompting the user for the value of n

First way: In the universe Define an object to hold the prompted value in the universe Use the @Prompt function

to define the object

@Prompt(‘Enter value fortop (n): ‘, ‘n’,,,)

Caution: this objectwill not parse but it willwork correctly whenused in a report

Allow the user to enter the value of n when refreshing a report



Second way: In the report This is a quick and dirty solution Caution: it may interfere with the database query optimizer



What to do in the report Convert the prompted value of (n) to a number and assign the value

to the variable Value of n

=ToNumber(UserResponse("Query 1 with bch_demo","Enter value for top (n): "))



Sample report #2: Display the top (n) countries

Step 1: Create the report Use objects Country and Number of guests For illustration purposes add the Rank column using the rank()

function



Step 2: Flag the rows that should be displayed Use a variable to flag the rows Create a new column to the right of the table Add the formula and assign it to a variable named Display row flag

=If Rank(<Country>,<Number of guests>)<= <Value of n> Then 1 Else 0

Result



Step 3: Apply ranking to the Display row flag variable Enter Top 1 Based on Display row flag



Result

Step 4: Remove unnecessary columns You may delete the Rank column because it was used for illustration

purposes only Do not delete the Display row column because the ranking is based

on this variable You may hide the Display row column



Hide the Display row flag variable Choose Table Format from the menu In the Pivot tab choose the Display row flag variable and click Hide



Step 5: Format the title

= "Top " + UserResponse ("Query 1 with bch_demo" , "Enter value for top (n):") + " countries by number of guests"

Result

Change the report: Refresh for a different value of (n)



Result

Problem with the variable approach The rows are not sorted A sort may not be applied after a ranking Users are not happy with this report

The challenge: Find a better solution


Topics

Introduction

Simple ranking




Q&A


Ranking with a Database Analytical Function 1/9

Database analytical functions Available in Oracle, DB2, and MS SQL Server Sort in descending order if you wish to rank by highest values rank() over(order by <measure> desc)

Example of the RANK() analytical function in Oracle SQLSELECT country, number_of_guests,

rank() over(order by number_of_guests desc) rank_value

FROM guests

COUNTRY NUMBER_OF_GUESTS RANK_VALUE

------------------------------------------------

Belgium 770 1

Greece 757 2

France 746 3



Create a measure object in the universe

rank() over(order by sum(Invoice_Line.nb_guests) desc)

Add the analytical function to the universe



Set the default aggregation to none Rank is not additive



Sample report #3: Display the top (n) countries

Step 1: Create a new report Use objects Country, Number of guests and the new analytical

function object Rank number of guests



Result

Advantages The database calculates the rank order therefore the rank order is

treated like any other variable in the report Sorts and filters are allowed

Step 2: Add the prompt to retrieve the value of n Possible approach: add a prompt in the query conditions pane



Prompt at the query level in the conditions pane Drag the object Rank number of guests into the conditions pane Caution: this will produce an error because an analytical function may

not be used in the where clause of an SQL statement



Prevent the users from producing such errors At the universe level, uncheck the option Can be used in Condition

on the Advanced tab of the Rank number of guests object properties



Step 2: Add the prompt to retrieve the value of n Better approach: See Sample report #2 for ways to add the prompt

Step 3: Include a custom filter Choose Format Filters from the menu Add the custom filter

= <Rank number of guests> <= <Value of n>



Result

Advantages of this approach Data may be sorted any way in the table

Disadvantages of this approach All data is retrieved from the database into the report because it is

filtered at the report level which may cause performance issues


Topics

Introduction

Simple ranking




Q&A


Cumulative Percentage 1/9

Sample report #4: Show the countries with the top 80% of guests

Step 1: Create the report Use the objects Country and Number of guests Sort by Number of guests in descending order



Step 2: Add a running sum of the number of guests Add a new column to the right of the table Enter the formula for running sum

=RunningSum(<Number of guests>)



Step 3: Calculate the cumulative percentage Add one more column to the right of the table Enter the formula

=RunningSum(<Number of guests>) / Sum(<Number of guests>) ForAll <Country>



The challenge: Display the countries that contribute 80% of the guests Possible approach: add a custom filter But it does not work: Cannot use aggregates in complex filters

The solution: use a database analytical function to calculate the cumulative percentage



Analytical function to calculate cumulative percentageselect country, number_of_guests,(sum(sum(number_of_guests)) over (order by sum(number_of_guests) desc)) / (sum(sum(number_of_guests)) over ()) cum_percent

from guestsgroup by country, number_of_guests

COUNTRY NUMBER_OF_GUESTS CUM_PERCENTBelgium 770 0.33Greece 757 0.66France 746 0.98Slovenia 22 0.99Portugal 21 1



Add a new object to the universe(sum(sum(Invoice_Line.nb_guests))

over (order by sum(Invoice_Line.nb_guests) desc)) /(sum(sum(Invoice_Line.nb_guests)) over ())



Use the object in the report Include the new object Cum. percentage number of guests in the

report The cumulative percentage is now calculated by the database and is

treated just like any other variable in the report



Prompt for the value of x percent Add the prompt to retrieve the value of x Use the same prompting techniques as in previous sample reports Convert the prompted value of x to a variable named Value of x

Custom filter the report for top x percent Add a custom filter to the report

=<Cum. percentage number of guests> <= (<Value of x>/100)



Result

Refresh for a different value of x


Topics

Introduction

Simple ranking




Q&A


Q&A

Sample reports will be made available for download

Contact information Maja Ferle, SRC.SI, Slovenia www.src.si [email protected]

Ranking in BusinessObjects Reports

Technology

ranking ranking

format ranking

ranking users

simple ranking step

simple ranking resultstep

ranking toolbar button

variable value of n

ranking capability endusers