Pg looks to be old (last update Apr 2000), so just off that DBD::PgPP is probably better. Do you have a specific reason for needing to use DBD::PgPP instead of DBD::Pg? I don't know for sure, but i would suspect that the latter is better (more robust & better supported), unless of course you need PgPP's ability to run where a PostgreSQL client library is not available.