Fan trap

[system]

Not sure how else I should describe it than what I have already done:

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Hi to everybody…i have 2 simple items in bo universe (2 aggregate indicators) , but when i put them together in a query, Bo think they are incompatible and so the result is this in the picture… he make 2 distinct queryes and then he join…but in pl/sql i usally do only a query, and i have the correct result…what i can do in the designer, to telle that the object are compatible, and that he can do it in only one query? Thanks to everybody!! [1.JPG] flavio20002 (BOB member since 2010-03-23)

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Hi All, Yes I have searched QUITE a lot on this forum and I think I have covered most of the posts related to this topic. I saw a lot of posts exlaining how to solve them but haven’t come across any that describe the cause of traps. Here are somethings that I need help with: Fan Trap: D1 --< F1 --< F2 Fan trap will not exist if the fact tables above are at the same level of granularity no matter where the dimensions/measures are coming from. Is this a fair statement? If yes, then in real wo…

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Dear, I’m suffering a problem in my universe…I freshly created it and it’s based on an RDB model, not a star-scheme unfortunatelly. I defined some contexts and alias’ed some tables in order to provide clean operation of the universe. Today I started creating some reports and all went fine untill the measure (yes, ther’s only 1 numeric in the entire report) started multiplying its value from the moment I started adding more tables to the query… So in the beginning I started …

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I am designing a universe I am facing a issue where for one record I am fetching 7 records and getting huge values , I should get one record. I have checked the all the joins but could not solve the issue. In my date table I have dates from day,week and month is this some thing to do with it needful advice is helpful thanks in advance bobtom (BOB member since 2008-01-17)

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I have read the article from Dave on fan traps,A->B->C. Does it mean that if B and C have measures in them then it is a fan trap. Or does it have to be a specific on the type of the measures like for example may be total for orders in B and number of orders in C. hartford27 (BOB member since 2006-11-22)

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If we have three tables and the middle table gets a one to many join on one key from another table ie this table being the many side and its get a one to many join on an other key from an other table again this table being on the many side, what are the common issues. GC_hill (BOB member since 2007-08-29)

And a good explanation of a fan trap by Andreas:

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Hi All, We are facing a Fan Trap problem. We are having 3 tables which are refered in the report. The relation between these tables is as: CRT_CURRENCY ----< PRC_RATE-----< CAPACITY_DTL. The data in these tables is as: Table CRT_CURRENCY: CCY_CD LNG_DESC -------------------------- GBP Pound USD US Dollar Table PRC_RATE: RATE_LINE_ID VER_NO CCY_CD TOT_PROMSD_REV -------------------------------------------------------------- 12345 1 GBP 1000 12345 2…

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Marek Chladny (BOB member since 2003-11-27)