How does SID generation on DSO level affect InfoCube load?

[#1]

Hi experts,

I am having big performance issue with data load to InfoCube. In the DTP monitor, the step "Conversion of Characteristic Values to SID" takes about 7-8 mins for each data package of 50000 records. I need to load about 20 millions data & this would take ages.

Below illustrates part of the data flow in my scenario:

DSO A   
DSO B   ======>  DSO X =====> Cube 
DSO C   

In the entry layer, I have DSO A, B, and C which contain header, line item records as well as master data. The option "Generate SID upon Activation" is checked for DSO A, B, & C.

Records from these 3 DSOs are consolidated & enriched into DSO X. In order to reduce load time I have unchecked "Generate SID upon Activation" for DSO X.

Data from DSO X will be written to the Cube 1:1 without any additional transformation logic.

My questions:

1. Since I have generated SIDs for the chars in entry layer, why it still takes so much time to for the SID conversion during Cube load?

2. In this case, is it necessary to generated SIDs in DSO X?

Thanks in advance for any advice. I am in desperate need for a solution to this load problem

Regards,

Meng

[Former Member]

Hi,

Load Master Data and activate it before before loading Transaction data... Reverse SID creation will degrade load performance.

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Thanks

BVR

[Former Member]

Hi BVR,

thanks for the reply. What is a "reverse SID creation"?

Thanks,

Meng

[Former Member]

Hi Merg,

The moment when you load master data and activate the same , Surrogate ID will be generated in SID Table. If you load fail to load master data before loading transaction data 'based on setting' system will create reverse sid's. While loading transaction if system is generating SID for missing master data will degrade your data loading performance. It is better practice to load MD before loading TD.

http://help.sap.com/bp_bw370/documentation/Multi_Dimensional_Modeling.pdf

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Thanks

BVR