SPI is a large interface. This ticket should be replace with specific, smaller, milestones for specific SPI features.
Ideally, the SPI interface would be available to PL/Perl via a $dbh object that mimics the DBI interface. There is a TO Do to do that. I see no reason why PL/Parrot shouldn't try to do that from the start. Note that it should be DBI 2ish, for whatever that means.
This is being worked on by cxreg on this branch: