Implement Chasm & Fan Trap at Universe level

Hi All,
Could anyone provide me some idea about 'how to implement Chasm & Fan Trap at Universe' practically??
Thanks for ur time & help.
Regards,

Hi
We cannot specify the real time scenarios here, search the SDN, forumtopic and many other site... there are lot of posts on that and solutions for that.
for a quick glance
These will occur at universe level while joining the tables.
chasm trap : The Chasm trap occurs when 2 u201Cmany-to-oneu201D joins converge on a single table, which has not been resolved by any context. The most common problem caused by a chasm trap is fetching more data than expected.
Fan Trap:A Fan Trap is a join between 3 tables where a one-to-many join links the first table to the second and another one-to-many join links the second table to the third. Inflated results are obtained when fields from all 3 tables are included in the query.
go trough these urls it may help you out
http://www.forumtopics.com/busobj/viewtopic.php?t=174405&sid=b10e205712fb102dae312173957b19f2
http://davidlai101.com/blog/2008/11/18/preventing-chasm-and-fan-traps/
http://biguru.wordpress.com/2008/05/01/its-all-in-the-universe-handling-chasm-and-fan-traps/
Hope this will help you!!!!!!!!!!!
Regards,
Rajesh

Similar Messages

Fan trap and chasm trap

Hello Experts;
I tried reading on the following terms but i am still not clear on it...Can anyone help explain and give examples on what a fan trap and chasm trap is. Thank you

Hi,
Both involve 3 entities, connected by parent-child (that is, one-to-many) relationships.
A Chasm Trap has a parent with 2 children (siblings).
A Fan Trap has a parent, a child, and a grandchild.
Another way of looking at it is that you have 3 tables, A, B and C: A is related to B, and B is related to C.
A Chasm Trap occurs when B is the parent of both A and C (that is, each row in B can be related to many rows in A, and it can also be related to many rows in C.)
A Fan Trap ioccurs when B is the parent of one of the other tables, but the child of the other.
See http://everythingoracle.com/obieefanch.htm
WARNING: Some people reverse the definitions as given above. Some people even use either term for either kind of relationship, indiscriminantly. Be careful when reading anything using these terms.

How to resolve the loop in universe level

how to resolve the loop in universe level

Hi, Kashim
In univese level loops resolved by Chasm Trap and Fan Trap methods.
Chasm Trap: A chasm trap is a type of join path between three tables when two many-to-one joins converge on single table, and there is no context in place that separate the converging join paths.
There is "many-to-one-to-many"relationship beween the three tables in the universe structure.you can define a context for each table at the many end of the joins.
A chasm trap is not dependent on the object types, the query could be made up of only dimensions,only details,or only measures,or any combination of the three types with the "many " tables for chasm to occure.
you can also detect the chasm trap Automatically, tool---->Detect context
To resolve the chasm trap, you need to make two separate Queries and than combine the results Depending on type of objects defined for the fact tables and the type of end user environment,
Fan trap: it is occured when there is a "one-to-many" join to the table that "fans out " into another "one-to-many" join to another table.
Avoid fan trap: The first place by relating all measure objects in the universe to the same table in the universe structure,Avoid placing a measure on anything other than the last table in a in a table path, which is the table with the "many" cardinality attached to it.
This methods is not recomended as it only works for measure objects and may result in inefficienies in processing the query. This resolution works the same for chasm and fan traps.
you can create more alias tables based on your requirement in single universe. and it is true conext, when two or more paths.
Theese methods also apply for resolving loops:
Short cut join also one method for resolving loops
Aggregate aware function used another waty for resolving loops
if you are not resolving the loop result is redusing the number of records.

Controlling data access at universe level

Hi,
I had a doubt in universe regarding the implementation of security.
Existing process: We had a portal called flex (intranet site)which the BO report has been integrated and for opening the report the name of report was clicked (hyperlink)
This report should show the data specific to the user profile logged into the portal.
Now if we want to restrict the data at universe level for each individual users accessing the report in portal our idea is to create a dervied table (which contains a list of userid's and project id's)in universe so that who ever logged into the portal and clicks on report he will see the data only related to profile
For example: The scenario would be a manager residing in a region need to see the list of projects which he is assigned to but not all of them.
Could you please let me know how can implement at universe. Kindly let me know if you need any futher information.
Thanks,
Eswar

Another way to do this is: (a) in your universe create a table that has a list of user names a long with their BOUSER id; (b) associate that list with fact tables or d imensions in the database, either using joins or by using a where clause as a filter or in an object definition using the syntax @variable(bouser); below is an exerpt from BO Designer guide.
Example:
@Variable
In the universe for a human resources database, you have an object called
Employee name. You want to restrict the returned data for Employee name
to the values authorized in the database for each user. This would allow
you to control what employee information each user is allowed to see. This
information is defined by their database profile.
You insert the @Variable function in the WHERE clause as follows:
Employees.Employee_Name = @Variable('BOUSER')
When the object Employee name is used in a query, the data is returned

Universe level creation using IDT 4.0.

Hi All
I need one clarification regarding Universe level creation using IDT 4.0.
I have created small Universe based on 5 tables and I have one alias on this and I have given necessary joins and Created business layer.
When try to create report using only 2 tables for the report and as we have given join so its taking equal join for others tables which we dnt need for this report, for that we are not getting correct results.
User is requesting that whenever they select any tables it should link each other table and if they want to add any field from other table universe should automatically link each other and provide desired results.
Is there any possible to bulid the universe based on the requirement
Thanks & Regards
Murali

Hi,
could you qualify/quantify what you mean by "wrong results"?
It doesn't sound like the universe is finished, or are these changing requirements you need to implement?
with regards to incorrect results, there must still be joins, cardinalities, loops , contexts missing, or other integrity issues to be finalized first?
Regards,
H

Problem with fan Trap.

Hi all,
I am having a problem resolving fan trap.
I am having a universe build over a MY SQL database.
The universe totaly consists of 4 tables and are related in the following way.
"A one to many B one to many C many to one D"
There are many 1-may joins between A and B and also between B and C.
There are measures and dimensions in A, B. And in C there are only measureas and 1 dimension.
When I pull the objects from all the three tables (A,B and C) there is a fan trap occuring and the values are getting inflated.
So I created an alias for B and defined a context for A, B and B alias and A,B and C. I have also checked the option of "Multiple SQL statements for different contexts."
But then I am trying to build a report in WebI and pulling the objects from both the unvierses there are 2 queries being generated and in the report, I am not able to pull the objects from different contexts into the same table.
If I select an object that is in context-1 the objects that are defined in context-2 are being dissabled and vise-versa.

You can set this behaviour in the universe parameters under SQL->Multiple paths->Allow seleciton of mutliple contexts .
Still since you are solving a fan trap you should keep this option clear.
A solution is to fetch the data from 2 different contents using 2 different webi queries and then use the Merge dimensions functionality in the report itself to join the results.
Regards,
STratos

Fan traps problem

hi all,
i am a fresh man in this deisgner.
Currently i facing a problem where the data fetching multiple values.
the query i capture from webi is like below
SELECT
FACT_SALES_ID.VALUE,
FACT_SALES_ID2.VALUE,
Derived_Table.PRODUCT
FROM
FACT_SALES_ID,
FACT_SALES_ID FACT_SALES_ID2,
Select FACT_SALES_ID.PRODUCT from FACT_SALES_ID GROUP BY FACT_SALES_ID.PRODUCT
) Derived_Table
WHERE
( Derived_Table.PRODUCT=FACT_SALES_ID.PRODUCT )
AND ( Derived_Table.PRODUCT=FACT_SALES_ID2.PRODUCT )
AND ( FACT_SALES_ID.TRX_MTHDATE <='2011-04-30') and (FACT_SALES_ID.TRX_MTHDATE > '2010-04-30' )
AND ( FACT_SALES_ID2.TRX_MTHDATE <='2010-04-30') and (FACT_SALES_ID2.TRX_MTHDATE > '2009-04-30' )
i doubt it is a fan trap. i have tried to understand the solution but still didnt work out.
any idea on it how to solve it in universe?
i really appreciate to any one who helps.
thanks alot

First question:
What is the purpose of the derived table?
Second question:
What are your measures? There are no aggregates there so it's difficult to tell.
Third question:
What is the relationship between the tables used in the query?

How To Capture The Inputs given for a Filter Defined at Universe Level

Hi ,
I have a conditional filter defined at Universe level
Wen this is used for Running Query using web Intelligence, It is asking for a prompt. That is cool and fine
Now my Question is that , I was unable to capture the prompt value being passed while running the Query .
For this object I am passing the values at universe Designer(3.1 SP5)
I would like to capture those prompts, I am not getting the same when I use UserResponse Function
Please Help me on this
Thanks in Advance

Hi
To capture the prompts values entered at query run time.
=UserResponse( "Prompt Text") Like ("Enter Values for Sales ID")
Will give the prompt entered value.
=PromptSummary()
Will give the list of prompts entered at Query run time.
Pleaas find the below link.
http://bobjblog.wordpress.com/tag/userresponse/
http://help.sap.com/businessobject/product_guides/boexir4/en/xi4sp5_ffc_en.pdf

How to Define a Required Prompt at the Universe Level

Apologies if this has already been covered somewhere... I searched and can't find the topic covered yet.
I've been under the impression for a long time that one could configure a Universe such that it would require a prompt on a dimension whenever that Universe was run, regardless of the tool or report. For example, you could configure an eFashion Universe such that any report or analysis built against it (Webi, Crustal, Design Studio, Lumira, PowerQuery... whatever) would trigger a prompt, perhaps on Year or State. The idea is that at the Universe you could prevent developers and self-service users from building "Select All" reports.
However, even with the use of LOV flags in the Data Foundation and Business Layer (e.g. "Force users to filter values before use"), I can't figure out how to make it work.
So, I have two questions...
Is it possible to include required prompts/filters in the Universe definition?
If so, how?
Thanks,
Josh

Hi...
Is it possible to include required prompts/filters in the Universe definition?
Yes..it’s possible to include prompts at universe level,
If all the reports are using same prompts, you can create at universe level and use same prompt in all the reports. You can define mandatory or optional prompt.
Following is the syntax for the function.
@Prompt('message','type',[lov],Mono|Multi,free|constrained|primary_key,persistent|not_persistent,[default_values])
The following are simple examples of @Prompt syntax.
Minimal use of the @Prompt function:
@Prompt('Displayed text ','A',,,)
Using the @Prompt with a LOV without default values:
@Prompt('Displayed text ','A',{'Paris','London','Madrid'},,)
Using the @Prompt with a LOV and one default value:
@Prompt('Displayed text ','A',{'Paris','London','Madrid'},,,,{'Paris'})
2 : If so, how?
In the condition's SELECT or WHERE field, right-click at the place in the expression where you wantto add a prompt and
select @Prompt editor from the shortcut menu.
In the Message box, type the message that you want the user to see.
Select Keep last value selected if you want the prompt to propose the values used for the previousreport.When the report is run for the first time, the default values (if any) are proposed.
Select Allow multiple selection if the user can enter or select more than one value.
Set the Selection mode. For Free selection, the user can enter any allowed value. For Constrainedselection, the user must select a value from a list of values. For Primary key, the user selects theobject name, but the object's primary key is used by the query. You can only use the Primary keysetting if Index Awareness is set.
Note:
When the Constrained option is selected and a List of Values is not specified, the corresponding Tab color turns to red, OK button is disabled, and on moving the cursor over the highlighted tab, the contextual tooltip displays a message indicating how to rectify the problem.
Set the Value type for the selection mode: Alphanumeric, Number, or Date.
If you have selected Primary key for the selection mode, set the Key type: Alphanumeric, Number,or Date.
If you are using multiple selection, define the list of values. Do one of the following: you can type orimport a list of values, or you can select a universe object.
Click the Default Values tab and define any default values. When you allow multiple selection, youcan set more than one default value.
Click OK.
The "@Prompt" editor closes and the prompt expression is visible in the condition's statement in the "Edit Properties" pane.
Validate the prompt and click Parse.When the syntax is
http://business-objects-xi.blogspot.in/2009/06/prompt.html

To restrict a object to a particular Group at the Universe level

Hi,
I have a object which should be restricted only to a particular group at the universe level.So when i define the universe we have to have explicit security that will restrict access to this object information from reports and from ad-hoc queries.I should restrict the object only to the particular group by a role based security.
Please help me out in this case.
Thanks in advance,
Madan

Hi Madan,
Please follow the below steps:
(In Designer)
1) Open Island Resort Marketing universe or any universe in Designer.
2) Goto Tools -> Manage security -> Manage Access Restrictions.
3) Click on New option - > Give the Restriction name - >click on Rows tab - > Click on Add button (New Row Restriction window comes) -> give table name For example:"Resort_Country" in the Table text box, under the Where Clause "Resort_Country.COUNTRY = @Prompt ('Which country?u2019,u2019 A',, MONO,FREE)"-> Click OK -> Click Ok.
4) Click on Add user or group - >Select the user ->Ok.
5) Click on Apply -> Click OK.
6) Save the universe and export it into the repository.
7) Cretae the new report (webi/deski) from the user the one who belongs from this group.
Hope above steps will helps you.
Regards,
Deepti Bajpai

Changing Prompt Order of Prompts defined at the universe level

Hi All,
I need to change the order of the prompts defined at the universe level.By default they appear in alphabetical order.
Thanks,
Shweta.

Hi Shweta,
If you are on XI R2 then you can try the following extended syntax for the prompt definition:
@Prompt('Region', 'A', 'Class\Object Name', multi,free,,,User:0)
@Prompt('Area', 'A', 'Class\Object Name', multi,free,,,User:1) ...etc
Else there is no other way to sort the prompt in the desired order. Either you have to prefix the prompt text with numbers
or alphabets.
Regards,
Rohit

Qualifying Prompt at the Universe level

Hi
I wanted to know whether it is possible to create a qualifying prompt at the universe level:
The first prompt will be u2018Select a Timeframeu2019 which will prompt user to select one out of following values
u2018Select Dateu2019 (multi select), u2018Select Weeku2019 (Multi select) and u2018Select Periodu2019 (Multi select). When user selects say any one value like u2018select Weeku2019 value , he will be give the Values for the Week number concenated with Week End Date. On selecting one or more values, the data for selected week numbers will be given. Same for u2018Select Dateu2019 where he can select Multiple Dates and select Period where he can select multiple periods.
Please let me know if there is any solution for this issue as this is a very high priority form my cleints.
Any help is highly appreiciated.

Do you users expect a fixed number of possible values in the 2nd selection level regardless which of the 3 selections was done on the 1st level (week, date, period)? Or should they be able to type in in the 2nd level their own values also at least for some of the 1st level selections (eg. period)?
Which database do you use?
Regards,
Stratos

How to create Current Year Filter at Universe Level ?

Hi,
I want to create a Current Year, Next Year and Last Year filters at Universe Level.
Can anyone help me with this.
I am using Netezza database and not able to find the appropriate date function in Netezza to accomplish this.
Any suggestions ?
Thanks

Hi,
You would somehow need to extract the Year part from the system date..
then
Current Year = Year
Next Year would be i.e Current Year + 1
Last Year would be i.e Current Year - 1
I guess this is the simple part... but you would need to find those functions on your RDBMS..
Hope this helps
Jacques

OpenDocument syntax with UserResponse at universe level

HI,
Can any one tell me what is missing or wrong in the following syntax of Open Document. I am using this at the universe level with user response and two parameters.
'<a href="../../opendoc/openDocument.jsp?sDocName=abc&sType=wid&sWindow=New&sRefresh=Y&lsSName:="UserResponse("Select Name:")l"&lsSID:='+dbo.EMPLOYEE ' ">'@Select(Employee Working days view\Employee_Name_ID)+'</a>'
Thanks!!!!
Bernard.

Hi Bernard,
UserResponse is for WEBI reports, in universe the formula is prompt.
Where clause = <FILTER KEY=u201D[MyVar]u201D>
<CONDITION OPERATORCONDITION="InList">
<CONSTANT NAME="@Prompt('Hierarchy node values','A','Sales
employee\LovHierNodeL03 Sales employeeBase',multi,constrained)"/>
</CONDITION>
</FILTER>
I replace in your syntax the UserResponse for @Prompt
'<a href="../../opendoc/openDocument.jsp?sDocName=abc&sType=wid&sWindow=New&sRefresh=Y&lsSName:="@Prompt('Select Name:','A',{'NAME1','NAME2','NAME3','NAMEn'},mono,constrained)]l"&lsSID:='+dbo.EMPLOYEE ' ">'@Select(Employee Working days view\Employee_Name_ID)+''
This is an exaple of MDX for SAP BI, Choose a dimension among the different u201Ctimeu201D dimensions available in a SAP Netweaver infocube.
0CAL@Prompt('CalendarLevel?','N',{'YEAR','QUARTER','MONTH','DAY'},mono,constrained).[[LEVEL01]]
I hope this help you.
Federico.
Edited by: Federico Sperling on May 11, 2009 4:39 PM
Edited by: Federico Sperling on May 11, 2009 4:39 PM

Ascending Order of Objects at universe Level

Hi Techies.
I am working on BO 3.1 Designer SP5.
I have one Period (Month Year) object at universe level and I have arranged the order of object as Descending by editing the properties of the object.
and when I use this object in the Query Filter section and making it as a Mandatory prompt, the values are loading in a different way rather than descending order.
Please help me on this......
thanks in Advance...

Hi
If you want to sort the LOV’s, use the LOV’s based on custom SQL option.
Please find the below sample code.
Sample Code
SELECT DISTINCT FIELD
FROM
TABLE
ORDER BY 1
And find the below link for more info.
http://scn.sap.com/community/semantic-layer/blog/2014/06/11/how-to-sort-the-list-of-values-in-the-prompts-screen

Implement Chasm & Fan Trap at Universe level

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