How does query uses context?

system · July 11, 2007, 11:42am

On what situation generally we used to create context?

what kind of issues generally we face due to context?

lets have some views on this?

Thanks,

Ranjan

ranjan.sahoo (BOB member since 2007-06-11)

system · July 11, 2007, 12:58pm

There is already a “sticky” topic at the top of this forum that deals with contexts and aliases.

I would suggest that you read that first and if you have a specific question feel free to post within that topic. That way we will (hopefully) see future discussions take place within one topic rather than getting fragmented throughout BOB. Thanks.

Dave Rathbun (BOB member since 2002-06-06)

system · July 11, 2007, 1:01pm

Let’s use a simple example … a single dimension table joined to two fact tables. The dimension table is “conformed” and has values A, B, and C. Fact table 1 has values A & B. Fact table 2 has values B & C. What happens if you query fact tables 1 and 2 in the same query? You will only return value B, because both joins are enforced and B is the only value in common.

By creating a context for each fact table (and proper settings in the universe), the SQL will automatically be split into two behind the scenes … one query against table 1 (returning A & B), and one query against table 2 (returning B & C). The results are then internally “merged” so that no data is dropped.

Dwayne Hoffpauir (BOB member since 2002-09-19)

system · July 12, 2007, 5:50am

Thanks a lot for your help dwaynee.

Will you please tell me what does exactly context do? is it a kind of mini universes? what kind of issues we will get if we dont create context?

Thanks,

Ranjan

ranjan.sahoo (BOB member since 2007-06-11)

system · July 12, 2007, 5:59am

Contexts are used to:

Resolve fan/chasm traps (incorrect overstating of measures)
Offer alternative paths between two or more tables, for example one for Car Leases one for Car Purchases

I strongly suggest you attend some official training classes (Designer) conducted by Business Objects or one of its licensed training partners.

Andreas (BOB member since 2002-06-20)

system · July 12, 2007, 6:04am

Thanks andreas for your suggestion.

that means it takes one path for car leasea and one path for car purchases. But i think this is to resolve loops formed due to car leases and car purchases.

But will you please give me an instance for chasm and fan traps?

Thanks,

Ranjan

ranjan.sahoo (BOB member since 2007-06-11)

system · July 12, 2007, 6:27am

Please:

Look at attending training classes here
Consider Shop@B B, in particular the book written by Cindi Howson
In addition, try a search on B B.

Good luck.

Andreas (BOB member since 2002-06-20)

system · July 12, 2007, 9:21am

Andreas,

Going ahead i will do the same.

Will you please give me a scenario for resolving chasm traps and fan traps.

Thanks,

Ranjan

ranjan.sahoo (BOB member since 2007-06-11)

system · July 12, 2007, 11:59am

[quote:e8698b98fb=“ranjan.sahoo”]Andreas,

Going ahead i will do the same.

Will you please give me a scenario for resolving chasm traps and fan traps.

Thanks,

Ranjan
[/quote]

Hey Ranjan,

Have you tried search as Andreas suggested

If you had then should have found Designer FAQ and mainly these 2 topics for fan and for chasm traps.

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

system · July 12, 2007, 12:11pm

I am going through. But unable to hit the website because of security reason, thats why requested to provide a scenario.

Thanks,

Ranjan

ranjan.sahoo (BOB member since 2007-06-11)

system · July 12, 2007, 12:19pm

Hi,
If you can write a post here that means you can access BO Forum Site, then which site you can not hit becuase of the security reason.

So can you tell us the site name?

In this post almost all the links ake to BO Forum site only and only one link takes to BO’s official website. And another one which tell about the Cindy’s book takes to Amazon.com, soare you trying to surf this URL? then i do not think it will be allowed. It’s not allowed even in my company.

BO forum is also allowed here because we are working on BO, else it would have also been blocked.

Omkar Paranjpe (BOB member since 2006-02-13)

system · July 12, 2007, 12:26pm

i cant hit the below site as provided by andreas in the link.

http://tips.businessobjects.com/tips/unvdes/tip/ut001/ut001.htm

Thanks,

Ranjan

ranjan.sahoo (BOB member since 2007-06-11)

system · July 12, 2007, 2:02pm

There are plenty of examples of fan and chasm traps already detailed within this very forum. There is a FAQ post as already mentioned. There is a Sticky topic at the top of this forum that discusses contexts and aliases. There’s plenty of material right on this site to get you started.

Dave Rathbun (BOB member since 2002-06-06)