http://help.sap.com/hana/SAP_HANA_Administration_Guide_en.pdf
Take a good read through the above document at page 133, it should help you in your partitioning quest.
Keep in mind - you can always change the partitioning methods on the fly and put the partitions back together into one piece, so you are not setting anything in stone. Of course, this can take some time with large tables, but it's still possible. At current client in a stage in environment, a 1.6b record table was merged and repartitioned in about 10 hours.
Regards,
Justin