Re: vacuum error "left link changed unexpectedly"

Ulrich Wisser <ulrich(dot)wisser(at)relevanttraffic(dot)se> writes:
> INFO: vacuuming "public.userclick"
> INFO: index "userclick_i01" now contains 13715747 row versions in 60640
> pages
> DETAIL: 0 index row versions were removed.
> 14209 index pages have been deleted, 14209 are currently reusable.
> CPU 2.46s/6.06u sec elapsed 186.45 sec.
> ERROR: left link changed unexpectedly

> To me this looks as the index userclick_i01 is corrupted.

No, it would be the one next to be processed. VACUUM does them in OID
order, so try something like

select indexrelid::regclass from pg_index
where indrelid = 'public.userclick'::regclass
order by indexrelid;

and look to see which index comes after userclick_i01.

regards, tom lane