Assign 0 to upgrade the database to have the pre-16.0 SQL SECURITY model for legacy system stored procedures when upgrading from pre-16.0 releases.
When upgrading from a version 16.0 or later database retain the current SQL SECURITY model (same as not specifying -pd).
Assign 1 to upgrade the database to have the pre-16.0 SQL SECURITY model for legacy system stored procedures (same as -pd y)
Assign 2 to upgrade the database to have the pre-16.0 SQL SECURITY model for legacy system stored procedures (same as -pd n).