"David Parker" <dparker(at)tazznetworks(dot)com> writes:
> The error only happens intermittently, but every occurrence is
> consistent:
>
> 1) always the same index - "attribute_pkey" on our "attirbute" table
> - one created implicitly by a primary key constraint
> 2) the error happens during a vacuum command
Hmm ... that seems a bit too consistent for a hardware issue doesn't it?
Have you looked at the index file with pg_filedump, or even just od?
regards, tom lane