hi Zhongwei,
SAP liveCache technology is an object-based enhancement of the MaxDB database system and was developed to manage complex objects (e.g. in logistical solutions such as SAP SCM/APO)
In solutions of this type, large volumes of data must be permanently available and modifiable. You can use SAP liveCache technology to represent data structures and data flows (such as networks and relationships) more easily and effectively.
And normally in SCN, SCM, APO system Oracle DB is used as a baseline DB which stores all data. And livecache store and calculates the real-time data based on DTP,SNP, heuristics So size of the livecache data is lesser as compared to Oracle DB.
For your 3 questions below ans can be given:-
1. The livecache is a complete database? The oracle database is useless?
Livecache is a complete DB and is based on SAP MAXDB and you can perform all DB operations on it.
Oracle DB is not useless as explained earlier.
2. In the normal progress, SPP communicate with livecache and oracle database?
Yes it does communicate with Livecache and Oracle based on the type of jobs and process chains and optimizations tranasctions its running.
3. The data in livecache and the oracle database is synchronized?
Yes it is.
Let us know if this has resolved your query.
Regards,
Ram