Hi Shuai,
Below are the comments from my end.
And you said "3) Yes, they're synchronized and if you have any inconsistency you might face errors during simulations, etc."
--> You can correct those inconsistencies in data. In case of APO/SCM system we use /sapapo/om17 & om13 t codes to correct those inconsistencies
Then:
1) How to backup the data? As I know Oracle hold the whole data, so we only need to backup oracle and not need to backup livecache?
--> Yes oracle does have whole data, but you need to backup both Oracle as well as livecache in order to have a complete live system without any data issues.
2) If I need to backup Oracle and Livecache independently, How can I keep the inconsistency when recover data?
--> the answer in given in reply of 3. And mostly the inconsistencies are related to update which is normally taken care by the Functional teams. Also one need to have a con-current backups defined. The backup statergy has to be like 1st Oracle backup and then livecache or both simultaneously. so that you get a point in time recovery done. or a offline backup during same time windows this will reduce your most issue related to data.
Also to be noted both Oracle/Livecache backup happening at same time affects system performance.
Let us know if you need more inputs on same.
Regards,
Ram