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[SHARING] WebFOCUS and SAP BW (MDX Query)

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October 22, 2009, 03:26 AM
Devi C
[SHARING] WebFOCUS and SAP BW (MDX Query)
Hi,

Is it possible to send complex MDX query to SAP BW.
What we are hearing from SAP team that we should not send complex MDX query to SAP BW.
If that is the case do we have answer for the below points


• Do we have bestpratices for handling qureys(MDX) for SAP BW.
• Do you people have faced any issues for geting huge amount of data from SAP BW.(for example more than 50K )
• Is SAP MDX qurey capable of handling some complex calculations.
• How is the overall performance with SAP BW compared to other Datasourse ex. Oracle, DB2



Please do the needful.

Thanks.

This message has been edited. Last edited by: Kerry,


WebFOCUS 7.6.4,7.6.9
OS: Windows XP
HTML,EXCEL,PDF
October 22, 2009, 05:20 AM
<JG>
You should not be sending MDX queries to SAP BW.
However if you mean the query generated by the WebFOCUS adapter that is a different thing.
You can see the MDX that is generated by turning on the client traces and if you are having a problem
you can paste this code into the MDXTEST function screen in SAP GUI to check what has been generated
works with WebFOCUS taken out of the equation.

There are a number of rules specific to cube processing in general principally to do with
how you navigate and what you select on

BW is not designed to be used as a datamart and you will have major performance problems trying to
retrieve thousands of rows. (BW has an inbuilt limit that prevents more than 1 million rows being processed)

Performance against SAP BW is atrocious when issuing complex requests when compared to relational DBMS
sources

From a documentation point of view most of what is available is either in the Adapter admin documentation
or in the devstudio online help under "SAP BW Adapter, reporting rules"
October 22, 2009, 09:59 AM
Devi C
Hi JG,

Thanks a lot for your quick response. your response is very helpful for us.

We are generating the query using the WebFOCUS adapter only.
When we run that query (from WebFOCUS) via SAP GUI,it is taking lot of memory(6GB out of 8GB total memory).
If we do simple count or compute (like adding two feilds or doing percent calc), the query fails even for 600 records.
Without any compute also, when we retreive more than 50,000 records (Not definite one ) , the query fails.
This error is not consistent(same qurey sometimes returning someother time its failing). we can not able to trace it.
Reports using SAP Cubes are still in development phase.We are afraid to move to production.(need to know how far its reliable )
Please give some suggestions to resolve it.


Thanks.
Devi
7.6.9 HTML EXL2K
SAP BW.

This message has been edited. Last edited by: Devi C,
October 22, 2009, 11:49 AM
<JG>
quote:
6GB out of 8GB total memory


That implies that the WebFOCUS request is not passing a good MDX request
and the vast majority of the processing is being done by WebFOCUS with much more data than you think.
Monitor the WebFOCUS server console to see how many rows are actually coming back.

AVOID defines against BW if at all possible.

Try to screen your data so that the minimum number of rows are returned.

If the Queries are being developed specifically for use by WebFOCUS try to make sure that the query contains the required rollups
at the correct level and ONLY retrieve at the level required.

If the queries are generic consider tailoring them specifically to your needs for WebFOCUS.

WebFOCUS is not a replacement for BEX or a BW web Query, it is an alternative method allowing additional features
and the ability to merge BW with other sources. It bites if you abuse it.