pg_autovacuum requires that the statistics system be enabled and

reporting row level stats. The overhead of the stats system has been

shown tohave asignificantcostunder certain workloads. For

instance, atight loop of queries performing "select 1" was found to

run nearly30% slower when stats were enabled. However, in practice,

shown tobesignificant 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.