APD based on Query fails randomly when using parallelization

[skirschstein]

All,

We are using an APD to write data from a Query to a CSV file. After this ran way too long, we set up a parallelization group (RZ12) and use that group in the APD.

We have set the package size for a partitioning characteristic (a date) to value 5.

For some reason the APD failes with error message "Error during parallelization: Assignment error: Overwriting of a protected field" (RSAN_RT352).

This happens about half of the times we run the APD. I haven't found anything regarding this error.

Any ideas?

Thanks

Stephan

[former_member623107]

Hello Stephan,

Were you able to figure out the root cause of the issue? I am also facing very similar issue with one of the APD.

Appreciate for your inputs.

[skirschstein]

Hi Nanda,

back then I analyzed the problem and found out and changed some things:

• It seems that if you use a partitioning characteristic, APD does not run the Query only for the characteristic values that are relevant according to the filters in the Query, but for all values that are available in the characteristic's master data table. No idea why SAP implemented it this way. This may result in very long runtimes although there are only a few filter values relevant.
• It seemed that the error only occurred when using a date (or any time characteristic) as the partitioning characteristic. We switched partitioning to a different characteristic (Postal Code, paket size 100) and it has been working ever since. I never found out why it failed with a time characteristic. My guess is that it has something to do with the way master data for time characteristics are read.
• According to SAP the cache should be deactivated in TA RSRT for the Query used in an APD.
• If the result of the Query/APD is quite large, deactivate processing in memory (RSANWB -> jump -> Performance Settings).

Hope I could help.

BR

Stephan

[former_member186445]

you have enough processes available for this apd?

are you launching manually or via process chain?

[skirschstein]

There should be enough processes available. It is started via process chain, but the error has also occurred when starting it manually and there was not happening much in the system at the same time.