BW Flat Cube support for BPC

[Former Member]

Dear experts,

We have NW BPC customer where over 13 dimensions are used in some models. BW cube limitation forces BPC to insert BW infoobjects to be stored on last BW dimension so cube read/write performance is poor.

Customer has MS SQL Server 2014 DB and 7.40 NW but as per described in note "2116639 - SQL Server 2014 Columstore Documentation" we cannot use Flat cube in real time (transactional) infocubes.

Can anybody, who has done specific datawarehouse remodeling/repartitioning for NW infocubes for more than 13 dimension, share their experience? Can anyone manage to do Flat Cube model in BPC with eliminating dimension tables like HANA Column based approach in SQL server?

Thanks in advance,

Regards

Ergin Ozturk

[Former Member · Accepted solution]

Hi Ergin,

You have 2 options:

1. Move to HANA where limitation of 13 Dimension is removed

2. Run a Full optimization of that Model. This will analyze which combination of Dimensions produces smaller DIM tables and re-arrange BPC Dimensions accordingly.

[Former Member · Accepted solution]

Dear Gersh,

HANA investment is not an option for this customer, full optimization (not light optimize) keeps infoobjects in the same last dimension. I know it has to rearrange but it does not..

If you have other options I would like to learn them.

Best Regards
Ergin

[Former Member · Accepted solution]

HI Ergin,

Can you please tell what are sizes of your Dimensions that are in first 12 Dimensions and size or your DIM table that is 13th Dimension?

Regards,

Gersh

[Former Member · Accepted solution]

Dear Gersh,

You may find last dimension has 5 infoobjects and ratio between fact table and dimension table is reasonable.

Also partitioning is not allowed and error message is given when trying to convert flat cube with reference to SAP Note which is leading to "SAP BW Columnstore Optimized Flat Cube on Microsoft SQL Server.pdf" document. In this document we are technically eligible to use writeable columnstore but since it is realtime cube repartitioning process does not allow to make it flat.

But if you create a Z* transactional flat cube in RSA1 from scratch, there is no prohibitation but in the document it is not advised.

Since this is not a bug I do not have chance to ask it to SAP support, but we could not found any roadmap which indicates future support of MS SQM columnstore flat infocube support for BPC cubes.

Can anyone who has authority to give feedback for MSSQL CS support for BPC cubes in forum may shed light on issue. Please we know HANA is promoted solution but not all customers can easily migrate to HANA.

Thanks in advance,

Ergin Ozturk

[gregor_dieckmann · Accepted solution]

Hi Ergin,

for me the statement in note 2116639 (Using SQL Server 2014 In-Memory Optimized Columnstore with SAP BW.pdf ) is clear, namely that flat real-time BW cubes with SQL Server are not supported. In this document you also find the reason. As BPC generates real-time BW InfoCubes, again the answer is also clear.

SDN is also not the place to get 'official' statements and with this topic it is even not clear whether such a statement has to come from SAP or Microsoft.

Regards,

Gregor

[Former Member · Accepted solution]

Dear Gregor,

I agree your points, and in my first message I also mentioned official statement is not supported.

But there are 3 points:

1) Flat Cube transition

2) ColumnStore Index

3) (In-memory) Columstore Index

I see reasons why Columstore can not be implemented but I could not understand Flat Cube transition is not allowed since I can create Real-time cube if I create it from scratch.

I do not expect official statements from people but maybe a guidence or a roadmap document, I guess I may ask for it in this media..

Thanks

Ergin