is it possible to rollback only a partition/subpartition? Is it possible to create a savepoint and to rollback only a partition of a table? 
Lets assume I created a monthly partition and subpartitions with a group_id for table x.

Now i run some stored procedures to alter the content in table x for a certain group id in a certain month. Before I run the stored procedure, i want to create a savepoint for the partition/subpartition and if necessary I want to rollback only the altered partion/subpartition and not the whole table.

I am asking for oracle and MSSQL.
Unfortunately this is not possible in SQL Server - you can of course create a backup, or create snapshots on the server (HyperV for example) to accomplish this. Other than that, it's not possible to only do it for a table - the closest I'd consider is differential back/restore.