Hi,
Let me try to answer your questions:
Q1. when i did a delta load second time to update amount from 100 to 200 in dso, does system read by the keys what is already there for amount and negate it and then update the updated value which is 200?
A1. Yes, you can see in the change log a before image (record mode 'X') with an amount of -100 (the original amount multiplied by -1) and an after image (record mode ' ') with an amount of 200.
Q2. Why did my cube not got updated like this?
material | amount
AAA | 100
AAA | -100
AAA | 200
A2. The initial update (record mode 'N') was 100. The second update is an aggregated value of 100 (record mode 'X' with -100 and record mode ' ' with 200). However, record mode is not a key field in the InfoCube so it will be aggregated by Request ID.
Best regards,
Sander