Following options is just my self’s view. NOT OFFICIAL.
PCC is built on datasource type framework , It is a implementation with no dependent with the type of database, Even more it is implemented by meta data , so it is also independent with what kind of payroll system you uses. Of course default delivered payroll process is work on SAP’s payroll process , But with few effort you can build you own one on your payroll system. So my answer is :
1. Declustering is not a mandatory condition for using PCC. PCC can work perfectly without declustering functions.
2. PCC have no requirement on database type ,no matter it is run on HANA or Oracle.
What’s the relationship between Declustering ,HANA, PCC.?
It is a powerful group . PCC have a spot feature : check payroll master data and payroll result. If payroll result is declustered the check program can use SQL to check the payroll result , if can really speed up the program especially for massive data.
Hana is another secret weapon, on one side decluster will produce a lot of data in database , but if you use HANA , HANA have powerful data compression ability, on another side HANA is a Hign speed train especial for data analyze. So it can make sure your check program run on the fly !