I just checked the state of vacuum in my PostgreSQL database and it's at a critical level:
$ check_postgres --action=last_vacuum POSTGRES_LAST_VACUUM CRITICAL: DB "postgres" DB: postgres TABLE: pg_catalog.pg_shdepend: 09:22 August 12, 2013 (40 weeks 2 days 4 hours 9 minutes) | time=0.52s postgres.pg_catalog.pg_shdepend=24379780s;86400;172800
but I am running autovacuum. Why would this happen?
check_postgresthink that this is critical?