pg_autovacuum requires that the statistics system be enabled and
reporting row level stats. The overhead of the stats system has been
-shown to have a significant cost under certain workloads. For
-instance, a tight loop of queries performing "select 1" was found to
-run nearly 30% slower when stats were enabled. However, in practice,
+shown to be significant under certain workloads. For instance, a
+tight loop of queries performing "select 1" was found to run nearly
+30% slower when row-level stats were enabled. However, in practice,
with more realistic workloads, the stats system overhead is usually
nominal.
-U username: Username pg_autovacuum will use to connect with, if not
specified the current username is used.
-P password: Password pg_autovacuum will use to connect with. *WARNING*
- When installed as a Windows Service, this option will be stored in plain
- text in the registry.
+ This option is insecure. When installed as a Windows Service, this
+ option will be stored in plain text in the registry. When used with
+ most Unix variants, other users will be able to see the argument to
+ the "-P" option via ps(1). The ~/.pgpass file can be used to
+ specify a password more securely.
-H host: host name or IP to connect to.
-p port: port used for connection.
-h help: list of command line options.