Difference Between Cognos and BusinessObjects 1

[cat12dog]

Hi All,
I have small doubt on these Business Intelligence tools of Cognos and Business Objects.
I Beleive that Drill Down /up and Slice&Dice are the MOLAP Functions.
But here what's my problem is
From the Business objects universes .unv data we will generate the reports over there will perform the slice and dice and drill functions.
In Cognos from the catalogs .cat data we will drill through to powerplay and using transformer will create the cubes .mdc using this data we will generate reports over there will do the same olap functions.
cube contains multidimensional data.
so how it will be cognos is desktop olap and BO is MOLAP.
OR Cognos Impromptu is desktop olap.And Powerplay cubes are molap.I have a great silly doubt on this.
Please give the deatiled description of DESKTOP OLAP/ROLAP/MOLAP/DOLAP.
What are the rolaps and dolaps.

Thanks In Advance,
HFL.

 

[doodvat]

Do a search for all the terms at

http://www.techweb.com/encyclopedia

It should give you a very idea about the differences.

 

[Sridharan]

BO is more of a DOLAP + ROLAP tool and not MOLAP tool as most people think?

DOLAP - Desktop OLAP
MOLAP - Multidimensional OLAP
ROLAP - Relational OLAP
HOLAP - Hybrid OLAP

In DOLAPs the Cube is stored locally on the user pc usually called Desktop. They use the local cube to do the analysis. So in BO there is no concept of Universal Cube which you access to do reports like in Cognos Powerplay instead each report you do in BO it internally creates something called MicroCube and stored within the report thru which it does the Drilling / Slice And Dice. Now if you try to Drill to a Dimension not in the MicroCube BO again hits the DB to get the required data. Hope the above would have cleared your doubts regarding BO.

In Cognos what you do is basically create a cube with .mdc extension which you use for reporting and analysis. AFAIK Cognos Impromptu is a ROLAP and not MOLAP as you've mentioned. A good example of MOLAP is Oracle Express where you create Cubes and store in Multidimensional DB (MDDBS).

This OLAP definition is a highly debatable topic and each people have their own versions.

Hope to see more comments!.

Sri

 

[cat12dog]

Hi Sri,

Thanks for Your Explanation.Its very useful for me regarding BO AND Cognos.

Thanks A lot,
HFL.

 

[Sridharan]

HFL,

Glad to be of assistance.

Sri