Clearing BW delta queues prior to migration of ERP system?

[Former Member]

I am trying to establish whether there is a need to clear BW delta queues in an ERP system prior to it being migrated to a new platform. The SID, logical system name etc will remain the same, but the server name and os/db will change.

So far as I can see, the delta tables will be transferred as normal tables, and therefore the delta queues will be as they were prior to the move. Therefore I can't see a reason to clear the delta queues prior to migration. (Obviously I need a synchronised restore point together with the BW system, just in case all goes wrong)

The clearing of delta queues in this particular system can take up to 7 hours sometimes, I am told, so I don't want to have to wait for that to be done before migrating, really. It is just another 7 hours on the total downtime which I will avoid if I can.

I raised a call with SAP, and they cannot point me at anything that says to do this (system copy guide only says to do this for a system copy - where the sid/logsys changes, whereas this is a migration, so all things except platform stay the same)

The first line guy from SAP offers his own personal recommendation to do it anyway, but said that there are no known problems in this area during migration. which is a bit of a non-answer, really.

So, does this mean everyone clears the queues, and therefore there have not been problems, or I am being terribly cautious and there are actually no such problems and it is perfectly legitimate to migrate without clearing BW delta queues?

A third party (the recipient of the export) has suggested to me that we need to do this prior to the export but I cannot see the logical necessity to do this - hence my question.

Can anyone offer their opinion or knowledge in this area?

Thanks, Andy

[former_member185954]

Hello Andy,

We have done migration without clearing queues, it works fine, there is no need generally because your SID and client of Source systems remain same, so your infosources remain same. The hostname changes are facilitated by RFC changes, so this activity I think is not required.

There would be some extra post processing activities that you would need to do after BW migration, which BW guys should know about.

Regards,

Siddhesh

[Former Member]

Thanks Siddesh, that is just as I thought. I have done migrations before and not worried about it.

You might be interested that when I pressured SAP to answer me, they stated that it is mandatory to clear the delta queues prior to an ERP platform migration.

However, when asked about where this is documented, they said this 'mandatory' requirement is not actually documented anywhere.

I remain to be convinced that this is a true requirement, but since I got this as an official response, I dare not in this case ignore the advice, and we will waste several hours clearing the queues prior to migration.

Thanks, Andy.

[former_member185954]

Hello Andy,

Its hit and miss, yes I agree, we shouldn't ignore SAP's advice, did you have a SAP Consultant onsite during your previous migration?

I would normally do a DRY run or Test cutover before migrating the production kit. In the DRY run, I can take my chances and play around.

If it doesn't work as expected, I would then go for clearing of queues.

All this with the SAP Consultant onsite ofcourse !

Regards,

Siddhesh

[Former Member]

No, no SAP-AG consultant was onsite. But I am a SAP certified migration consultant, so I don't need one to do this for me.

This is why I was surprised by SAP's response. I knew of no specific requirement to do this, because logically the structure of the tables does not change - which is the usual reason for having to clear delta queues.

Thanks, Andy

[former_member185954]

Agree with you.

Regards,

Siddhesh