FAN TRAP-DATABASEBy:-Bharat Kunwar

FAN TRAP

It occurs when a “One to Many” join links a

table which is in turn linked by another “One to

Many” join.

#.There are two ways to solve Fan trap:

Creating an alias and applying aggregate

awareness function. This is the most effective

way to solve the Fan trap problem.

Using Multiple SQL statements for each

measure.

Fan trap occur in a situation when a model

represents relationship between entity types

however a path between certain entity

occurrences is ambiguous.

Example: (Staff)-1:N-has-1:1-(Division)-1:1-

operates-1:N-(Branch) in this model it may be

impossible to determine the branch a staff

belongs to, in the situation when staff belong to

division having more than 1 branches.

Reference

• http://everythingoracle.com/obieefanch.htm