Re: vacuum error "left link changed unexpectedly"

Ulrich Wisser <ulrich.wisser@relevanttraffic.se> writes:
>    indexrelid
> ---------------
>   userclick_i01
>   userclick_i02
>   userclick_i03
>   userclick_i04
>   userclick_i05
>   userclick_i06
>   userclick_i07
> (7 rows)

OK, so userclick_i02 appears to be the broken index.

> How do I proceed? How can I tell which files are involved?

See contrib/oid2name, or read
http://developer.postgresql.org/docs/postgres/storage.html
and work out the index file name for yourself.

If you don't already have a copy of pg_filedump, see
http://sources.redhat.com/rhdb/utilities.html

            regards, tom lane