>> INFO: "cpe": found 95498 removable, 18757 nonremovable row versions
>> in 11117 pages
>> DETAIL: 0 dead row versions cannot be removed yet.
>> There were 280173 unused item pointers.
>> 0 pages are entirely empty.
>> CPU 5.35s/0.99u sec elapsed 724.38 sec.
>
> How many idle transactions are there?
>
Not sure. I don't expect that there were many, their system isn't
very highly loaded compared to most of our customers systems.
The way that they reported the problem to us was that if they enable
autovacuum, when ever it runs (about 4 times an hour) it would stop
processing the things it needed to process, due to table lock
contention for several minutes.
Their workaround had been to run a daily autovacuum at the lowest load
time of day, to cause the least disruption.