Christopher Smith <christopherl_smith(at)yahoo(dot)com> writes:
> ERROR: _mdfd_getrelnfd: cannot open relation TABLE_NAME: Input/output error
This is a hardware failure: your disk drive has dropped some sectors.
I don't think you can do anything about it except go back to your last
backup :-(
Oh, and buy a new disk ASAP, before you lose any more data ...
regards, tom lane