(auto) vacuum mysterious

Hi There

My Name is Martin
And we are running PostgreSQL 9.5.3

We are doing a lot of deletes updates and Inserts on some tables

Until now we didn’t Encounter so much Problems with the vacuumizer but in the last view days we have the fact the vacuum cannot remove dead rows anymore

I know it is the case when there are other Long running Transactions running but this isn’t the case

The vacuum Output Shows only that it cannot remove dead rows.
But not why?

Is there a way to see futher Information to see that? To see which session is blocking the vacuum Job?

Thanks Martin

DETAIL: 2066873 dead row versions cannot be removed yet.
There were 685985 unused item pointers.
Skipped 0 pages due to buffer pins.
0 pages are entirely empty.
CPU 1.75s/1.07u sec elapsed 2.84 sec.
INFO: vacuuming "pg_toast.pg_toast_30145032"
INFO: index "pg_toast_30145032_index" now contains 0 row versions in 1 pages
DETAIL: 0 index row versions were removed.
0 index pages have been deleted, 0 are currently reusable.
CPU 0.00s/0.00u sec elapsed 0.00 sec.
INFO: "pg_toast_30145032": found 0 removable, 0 nonremovable row versions in 0 out of 0 pages
DETAIL: 0 dead row versions cannot be removed yet.
There were 0 unused item pointers.
Skipped 0 pages due to buffer pins.
0 pages are entirely empty.
CPU 0.00s/0.00u sec elapsed 0.00 sec.
VACUUM