cognos, ETl

[rangarao]

hi!!!!
i am just in process of learning about data ware housing concept and i know some thing about cognos, my question over here is we can build reports are cubes using improptu and transformer, but where does the concept of ETL come, beocs some of resume i had seen says "i used informatica power mart to extract data" why do we need to use this ETL terminology when we build reports or cubes from cognos directly

 

[Sridharan]

rangarao,

ETL is a process of a Datawarehouse Setup and is not used for report generation using third party olap tools like Cognos, Microstrategy, Business Objects, Brio etc.... ETL stands for Extraction Transformation and Loading.... Its a process used to populate data from variety of sources into the datawarehouse and for that we have ETL tools like Informatica, even Cognos have their own ETL tool i suppose its called Decision Stream.... as the name itself says Extract data from operational data store and Transform it for loading into the DW and finally Load the data....

to put it simply ETL loads huge volumes of data into the DW.... while Cognos Impromptu or Transformer takes the data from DW for analysis purposes....

Hope u now get some idea about what ETL is!!! More questions come back....


Regards

Sridharan

 

[rangarao]

thanks for u'r help, but little late , i had learnt this from lot reading, and if u were little early it would have been lot of time saving for me