I want to ask the question:
D <- F1 ->F2
for the condition,if it’s the chasm trap?
thanks
vince.story (BOB member since 2006-08-30)
Looks like a chasm trap to me.
Damocles 
(BOB member since 2006-10-05)
Why are you joining two fact tables?
Are they, for example, orders and order lines, in which case you’d run into fan trap issues too?
hello Damocles,
thanks,if it’s,how i reslove it?
hello Mark P,
thanks for your reply.
i guess the model will exist in my universer,so i post the model,i hope i can know it before i meet it.i don’t know the model is belong to chasm or fan trap?maybe ,can you help me to realize it,thanks.
vince.story (BOB member since 2006-08-30)
From our FAQ Designer: What is a chasm trap, how to resolve it.
It is also possible that you should have two totally separate universes. Just because some common columns exist in two fact tables does not mean that the tables are designed to be used together.
It is wise to look at FAQs and to do a search before posting a question.
Anita Craig 
(BOB member since 2002-06-17)
Hello Anita Craig,
thanks,just i want to hear the word"some common columns exist in two fact tables".
vince.story (BOB member since 2006-08-30)
[quote:4027c42ec5=“vince.story”]thanks,just i want to hear the word"some common columns exist in two fact tables".
[/quote]
I don’t have a clue what this means! 
Anita Craig (BOB member since 2002-06-17)