Size of table delta log

[abk07]

Hi All,

The ABAP developers in our company wants to create a column table in SAP HANA and insert millions of rows into it. They have tried to do that but complain that the performance is low due to the creation of delta log for the tables. So I suggested them to switch off the delta log and start inserting the entries. Now, they have disabled the delta log programmatically and ask me to check the size of the delta log. The question is. is there any way I can check the size of the delta log of the table?

Thanks,

AK

[lbreddemann]

Your ABAP developers don't seem to know what they are talking about.

Inserting millions of rows into a column store table is usually not constraint by the very mechanism for changing data them.
And there is no option to "switch off" the delta store.

Maybe, your developers heard about using "no logging" tables with other databases (back in the '90s when they learned their SQL) and now think that this will solve their problems here. Who knows.

What is known is that this performance problem requires analysis so that the actual reason for the slowness can be identified.

Common issues with loading data in HANA revolve around issues like

• not using bulk inserts/updates
• using cursors
• using (nested) loops to issue INSERT statements
• triggering too many delta merges/not controlling delta merges
• running into locking issues

I highly recommend reviewing the code and measuring where time is spent and go from there.

BTW: there are plenty of SAP notes about performance analysis and optimization as well as the performance and troubleshooting guide. These should be the first documents to consult.