Fan traps problem

[Former Member]

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

[Former Member]

Hi all,

Thanks for helping.

the problem has been solve by just adding context into the query.

The value i fetch now is correct.

Regards

[Former Member]

how to know fan trap and chasm trap without seeing the universe

[Former Member]

Adding to the above questions can you tell us what kind of cardinalities you have for the tables you are using. Also if PRODUCT is a measure you need to declare this as a measure say sum(product). even then if you get the results to be duplicate then we say its a trap.

Thanks,

karthik

[Former Member]

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?