If you dont want to migrate all the data to your new instance, then better go for a fresh installation instead of upgration and load the necessary data.
Again we can't take the decision only on this parameter for Upgration vs Installation. Do a detailed analysis with more parameters for your decision.
Actually we wanted to know if we could perform a partial data migration using the migration harness or some other means
Dear SI and Ariba Consultants
We are seeking Request for Proposal (RFP) for performing partial data migration. The requirements are as follows
a. Migrate only open data ie not fully paid from Ariba Buyer 8.2 instance to Ariba Buyer 9r1 instance. Migrated data include transaction objects and dependent system objects
b. Prepare data migration plan and communications plan
c. Perform pre- and post- data migration sanitation checks
Interested parties please send your proposals to email@example.com by 15 Sep 2012. The proposal shall include the following
a. Migration Plan and Approach
b. Estimated Duration
c. Estimated Cost (in USD or SGD)