Matteo Sgalaberni <sgala(at)sgala(dot)com> writes:
> 22 daemons that have a persistent connection to this database(all
> connection are in "idle"(no transaction opened).
You may think that, but you are wrong.
> INFO: "cliente": found 0 removable, 29931 nonremovable row versions in 559 pages
> DETAIL: 29398 dead row versions cannot be removed yet.
The only way the above can happen is if there are some fairly old open
transactions. Looking in pg_stat_activity might help you identify the
culprit(s).
regards, tom lane