>> - hard transactions: cutting the power to a PostgreSQL server
>> may cause data loss and/or data corruption.
That is false; Postgres is secure now against power failures,
at least if you run in the default mode with lots of fsync()s.
The WAL feature planned for 7.1 should make performance better,
but it won't make any fundamental change in reliability for power
failures.
The existing server does not offer any protection against disk hardware
failure, however. RAID disks might be an adequate answer to that.
regards, tom lane
