Guest

• Jun 24th, 2006

 

Actually FAN TRAP is a problem that occurs in Universe Level. Loop occurs while we design the universe.

Two Types of Loop Problem:

1) FANTRAP PROBLEM solved by ALIAS METHOD:

Definition: Two One-to-many table link eachother is in turn linked another one-to-many table. 

2) CHASM TRAP PROBLEM solved by CONTEXT METHOD:

Definition: Two Many-to-one table converges on one single lookup table.

Loop can be detected while INTEGRITY CHECK is done. An option is there as "Check for LOOPS" available. By "Detect Loop" we can choose what to be applied for solving the loop.

Vineela

• Apr 25th, 2007

 

 
When there is a series of one to many join in the tables, a Fan trap is resulted.
This may cause incorrect results to be returned when a query includes objects based on both tables.
For example : Associate, Project , Dept tables.

One associate may work for N Projects , and those N projects may be Executed by N Dept....The report executed with the Associate table and the Dept table objects may produce that One Associate belongs to many departments.

To avoid this

Create a Alias table for Project , which is joined to the Associate as One to one mapping table.

Create a Alias table for Dept, which is joined to the Project as One to one mapping table.

That means one associate , will be shown working for one project, and one project belongs to one dept.

Which will now result in One associate working for one Dept.
 
There are many other methods to solve Fan trap !!

Creating Manual Context , Using @ Aggregate Awareness Etc etc - based on the Business scenario these can be used.

vinod3035

 Profile Answers by vinod3035 

• Jul 11th, 2010

 

The above answer is  well and I understood but Alias mean Duplicate name given to the original table? What about the Original table? How it will be include with in the Query?Associates=>Projects=>Departments.