We were experiencing extremely long load times using the OLAP connector. Apparently it has something to do with the method that SAP uses to pass back the data. Also, there were limitations with the amount of data you could pull.
For example, we were pulling inventory trend data. To pull data for a month, it was taking 45 minutes to get the data. When we checked the performance in BW, we could see that the query itself was running within minutes. All of the extra time was being consumed for returning the data to QlikView.
We have since switched to using underlying DSOs and tables and have been very happy.
what you should use depends on your experience and your SAP knowledge. If you have no SAP BW system and you only want to use SAP BW I would say - Do not install SAP BW only for QlikView. You should also be carefull from the legal point of view because SAP has the possibility to debit you with a OpenHub license - I think but I'm not sure. It is not so clear.
If you have no SAP BW I would suggest:
- Do not introduce SAP BW only to get the data for QlikView. If you want to use the SAP Service API (SAP
BW datasource extractors) which is very powerful I suggest you will look around for a 3rd party connector. I
made good experience with the Theobald connector. It also supports the connection to the SAP Service API without the introduction of SAP BW and I think all other possiblities of the QV SAP connector.
- Use the QV SAP connector to extract the SAP tables, reports, ...
If you have an SAP BW system I will suggest to collect the data from the SAP BW system because it will have no performance impact on your SAP ERP system. And your SAP ERP system is much more important than the SAP BW because you will do your operational business with your SAP ERP and the reporting with SAP BW.
- Use an extractor what you want that supports the extraction of the SAP BW system.
Hopefully it helps you a little bit to find a good solution for your tasks.