This evening, i received another CSR that i need to follow up as Oracle IT support. This time is related to the Oracle BI Discoverer report. When the user tried to open one of the workbook they have in the database, it give them this error message: “Join configuration cannot be resolved. Reason: more than 1 of the detail folders uses non-aggregated items. Attempt to open workbook failed.”

Ups whats going on here. How to solve this weird error message? I browsed through guugle, then found out this website. This Manchester Campus website said that :

A. This is caused by a conflict between the default settings in Discoverer, and the data that the University wishes to hold in the Business Intelligence Database

and mention this “magic” word :

It is very easily resolved:

Wow, i’m so thrilled to see the next step how to resolve this error…(i am so sure you either)

So here are the steps that you need to follow in order to fix this Discoverer BI warning message :
1. Open Discoverer Plus (not Viewer) and close the Wizard asking you to create new/open existing workbook
2. On the File Menu, go to Tools, Options
3. Click the Advanced tab
4. Check the second checkbox down, “Disable fan-trap detection”

I am sure you can open the report now.

So what is this Fan-Trap Detection actually?

A fan-trap occurs when the data items in two folders are not directly related (such as with a Customer ID), but do have a relationship based on the data items in a third folder.

As example : you have 3 folder that you want to pick up the fields. Just named it Folder A, B and C.
Folder A and B don’t have direct relationships build in the Discoverer Administrator, but Folder A and C have the join relationships also with folder B and C. Then you try to get the fields from those 3 folders. You get what i mean?

Discoverer will automatically detects and resolves potential fan trap queries into multiple SQL statements to obtain normal expected results. If the Discoverer cannot resolve a fan trap, Discoverer prevents the worksheet from being running and then displays the warning error message dialog.

Just keep in your mind that if you disable fan trap detection, Discoverer still detects potential fan trap configurations, and resolves them by generating the correct SQL and displaying correct worksheet data. If Discoverer cannot resolve a fan trap, it displays the worksheet data and does not display a warning message dialog. The result of disabling fan trap detection might result in a query based on an unresolvable fan trap configuration, generating potentially misleading results.

So its actually depend on what you want to do. I suggest you better fix the relationships between those folders and try run your workbook again. So it would save in case of misleading data results in your workbook.

If you want to see more information about this fan traps, try see your Oracle Application Server Discoverer Plus User’s Guide. But i believe that we to “busy” open the user guides