Friday, July 2, 2010

Bursting Explained - Part I

I have been asked by so many users what happens behind the scenes when Cognos bursts a report? Why do burst reports take longer to complete? etc. And I have explained about master-detail relationships and its impact on Burst reports in an earlier post. In this post and the next couple of posts I am going to try and cover the various burst scenarios and how many SQLs Cognos fires against the backend in each scenario.

Bursting is made up of 3 components:

The Burst Query or Report Query: The report query that needs to be burst. The report could be a single query report or multi-query report. In case of a multi-query report, each data container in the report needs to have a master-detail relationship set up with the burst group query.



The Burst Group Query: The query that decides the burst group. For each record in the burst group query the report is sliced.

Example: A report needs to be burst for each Sales Regions. In this case the burst group would be the Sales Region. The report is sliced for each Sales Region record generated by the burst group query.


The Burst Recipient Query: The query that provides the recipient information.



Scenario 1: A single Burst Query, Burst Group Query, Burst Recipient Query.

In this case the list in the report, the burst group and the burst recipient information is fed by a single query.

Example: Burst a Sales report based on Sales Regions to be made available to users through Cognos Connection Directory.

Query 1 Data Items: Year, Sales Region, Sales, Recipient.

Recipient - CAMID('Everyone')

In the above Example, since burst group, burst recipient and list report are sourced from a single query, Cognos runs this query once, retrieves the entire data set and then slices the report output for the various sales regions. Hence only 1 query is fired by Cognos in this case.



Links to Part II, Part III

 

7 comments:

Mrcool said...
This comment has been removed by the author.
Mrcool said...

Hi,

I am getting an error while implementing this in cognos 10. Could you please let me know if this works in cognos 10.1

Thanks,
MC

Zephyr said...

Hi MC, Can you share the error message you are receiving?

I do have one defect logged for Bursting in 10.1.1. So if you could let me know the error message, I would be able to verify if its related to the defect I have loggged.

Mrcool said...

Hi Zephyr,

Thank you for your quick response.
I was getting kind of parsing error. After changing the recipient expression to
'CAMID(":Anonymous")'
fixed the issue.
Thank you so much for your post, it helped me a lot.

Thanks,
MC

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Anonymous said...

I think it's important to point that Crosstab reports can't be burst.

CFA Level 1 December 2009 said...

Hi,

Is there a way to audit the bursted report? IE view who actually was sent an email?

Thanks!

Teresa