No, the -rescan only works on your wallet.dat Hopefully, you have a safe copy somewhere.
I'm just suggesting that you move it and see if the client is able to run and sync the blockchain after it generates a fresh (empty) wallet.dat
If the database errors still occur look at the file permissions and/or check the drive for errors
Ubuntu 16.04
./ppcoind --help
PPCoin version v0.5.4ppc-beta
and
Peerunity v0.2.2.0-g810bf84
yes have a copy of wallet
and before upgrading I have seen my xxx PPC
now only 0.519990

have already done a new run and sync, then wallet was understandably empty...
-> copied wallet in it and then error
permissions and drive are ok