>you can define appointed schema of SP in catalog, but you can not define schema in SP of content, it is default in schema(_SYS_BIC) so far.
As of SPS6, you can specify the schema for creation for the procedure when creating in the Repository (via the the new procedure editor that runs from an XS project).
The main difference is that when creating in the Repository you get a managed design time version of the procedure. This means that you track version management changes and you have a central transport mechanism. You can create a delivery unit which contains all your development objects and easily install that into another HANA system. Also only Repository procedures in a project can be debugged. For these reasons, SAP recommends that you create your procedures in the Repository.