Autovacuum Question

PostgreSQL 8.1.3

Question on autovacuum.

autovacuum_naptime (integer)
Specifies the delay between activity rounds for the autovacuum subprocess.
In each round the subprocess examines one database and issues VACUUM and
ANALYZE commands as needed for tables in that database. The delay is
measured in seconds, and the default is 60. This option can be set at server
start or in the postgresql.conf file.

Does this mean that each run of autovacuum will vacuum/analyze all tables
that need work in the database that autovacuum is looking at?

The reason I'm asking is that I have ~172 non system tables in each
database, so if autovacuum only does one table per run, I don't think it
will ever get caught up (since there are almost 35k tables in total).

Also, with over 200 databases, does this mean that a database will only get
checked once about every 3.5 hours, or does autovacuum run on the database
that needs the vacuuming the most?

Thanks,

Chris