SAP BW and RDW

[shaashish1]

I am working in a project that has been integrated with Cognos 8.4 and SAP ECC6. We have dataflow as described below:

""""SAP ECC6 --> SAP Business Warehouse (BW) --> Regional Datwarehouse (RDW) ---> Cognos 8 Reporting""'''

Now my question/ Can we eliminate the SAP Business Warehouse (BW) and move directly to Regional Datwarehouse (RDW) for reporting?
What major role --> SAP Business Warehouse (BW) is doing? Pleaseee let em know merits and demirits

[cognostechie]

In the new versions , FM can directly read from SAP BW (now known as SAP BI). This has an advantage that the heirarchies defined in SAP BW is directly imported into FM without having to re-create the whole scenario. You can bring the SAP BW cubes stright into FM and publish it and then the same can be used in Report Studio and Analysis Studio. You can also bring in the relational tables from BW into FM and use that in Cognos studios.

Since you have another DW on top of SAP BW, you can use that too but do you have that because that's how it was done before the new versions of Cognos came up? or your RDW restructures the data from BW?

SAP BW is the DW that is providing data to your RDW so that is the source for RDW. You are actually duplicating things by having an RDW. Even in earlier versions of Cognos, you could directly read from SAP BW because SAP BW is a collection of tables in an RDBMS so FM can directly use a data source for that database and read from the BW tables. That's how I used to do it prior to 8.3.

[shaashish1]

Thank you for reply, So it means that I can remove the RDW from the Architecture... and directly use my Reporting from SAP BW.

We are using Cognos 8.4 and TM1, I do not have more idea on TM1 but am aware with Cognos 8.4 (RS, QS, FM, MS).

We have some reconcillation going on SAP BW and that is why I think the Design is such way. It also happens that the data do not match up between SAP BW and RDW ( Sorce for Cognos Reports).

1. Please send me some Architecture Design fro SAP, Cognos 8.4 and TM1 integration?
2. Does TM1 gives Complete reporting as Cognos 8.4?

[MFGF]

Just a minor word of caution.  Using the original query engine in Cognos 8, performance against some SAP BW cubes can be, um, let's say not quite as lightning fast as some might hope.

Using the new Cognos 10 Dynamic Query engine can give far better response times - but of course this is not available in Cognos 8.

Before you consider dumping your RDW from your architecture, you may want to try your C8 instance directly against BW to judge whether performance is as you'd expect.

MF.

[cognostechie]

I would also check whether the RDW has data only from SAP BW or other sources too. If it has data from other sources and joining/connecting the data from SAP BW, then that explains why RDW was implemented. 

TM1 cubes can be published to Cognos Conenction from Framework Manager and used in AS and RS.  However, it is still an OLAP so it would not be able to provide you with relational reporting features. So I would not say 'complete' reporting unless your reporting is based off of cubes only. SAP BW is also published as apackage from Framework Manager and can be used in AS and RS. This would give you the brief idea of architecture.

Since the data does not batch between BW and RDW, I don't know how you would get rid of RDW anyway because the data in BW is probably correct as that is the source.