Disadvantages of Write-Optimized DSO

[Former Member]

Hello experts,

is there any problem (according to the performance or the results) if I want to report on a Write-Optimized DSO in contrast to a Standard DSO?

Thanks in advance.

[mansi_dandavate · Accepted solution]

I dont think there such DSOs are good for reporting since they have only actgive table.. and no activatio of requsts...

So while reporting it will be generating SIDs which will affect performance...

Edited by: mansi dandavate on Aug 11, 2009 9:50 AM

[Former Member]

Hi,

Write Optimised DSOs are not to be used for reporting due to performance reasons. They are used for reducing the loading times (since there is no activation) and are used exclusively as a staging layer. Except in exceptional circumstances, we donot report on them. As per your requirement, if you are just looking for a staging layer and are inclined to reduce the loading time, you can go for write optimised DSOs but remember that during querying, due to SID generation, the performance of the query will drop.

Hope this helps.

Regards,

Saikat

[Former Member]

Here some further explainations:

I want to load the data from PSA to DSO exactly as it is in the PSA. Therefore I would use a Write-Optimized DSO without a semantic key and without any check for uniqueness. In the further data flow I want to load the data from the Write-Optimized DSO to different cubes. Reporting takes place on the cubes. Only on exceptional circumstances it should be possible to report on the Write-Optimized DSO directly.

Edited by: Dennis Halboth on Aug 11, 2009 10:00 AM

[mansi_dandavate]

Dennis,

Have a look at what SAP help has to say....

For performance reasons, SID values are not created for the characteristics that are loaded. The data is still available for BEx queries. However, in comparison to standard DataStore objects, you can expect slightly worse performance because the SID values have to be created during reporting.

If you want to use write-optimized DataStore objects in BEx queries, we recommend that they have a semantic key and that you run a check to ensure that the data is unique. In this case, the write-optimized DataStore object behaves like a standard DataStore object. If the DataStore object does not have these properties, you may experience unexpected results when the data is aggregated in the query.

[Former Member]

Hello,

Then you should not go for reporting if it doesnt contain unique records or if its not using semantic keys.

the aggregation will not happen properly and you will get wrong results.

I found a help link as well which explains you this.

http://help.sap.com/saphelp_nw70/helpdata/EN/b6/de1c42128a5733e10000000a155106/content.htm

Dont use it for reporting if conditions mentioned are not satisfied.

Regards

Ajeet

[Former Member]

Hello,

Write optimized DSO's are not good for reporting unless if its a very very smalll amount of data.

if you are planning to store the data say in several hundred thousands in the DSO then it will have a poor performance and if its in millions then dont use it.

There is a no option for SID generation in write optimized DSO's and therefore there is no chance for further improvement in the performance.

Its good for quick staging but not for reporting.

Regards

Ajeet