Autovacuum working / not working ?

Hi All

I hope that someone can perhaps assist me with some insight into the
autovacuum as well.

I have a couple of Postgresql databases at a client site.

The autovacuum is enabled, however when I run the sql query below it does
not return any results:

Query:

select relname, last_vacuum, last_analyze,last_autovacuum,last_autoanalyze

from pg_stat_all_tables

where schemaname = 'public';

results:

postgres-# where schemaname = 'public';

relname | last_vacuum | last_analyze | last_autovacuum | last_autoanalyze

---------+-------------+--------------+-----------------+------------------

(0 rows)

They are running a combination of postgresql 8.1 and 8.3
over a couple of servers.

The current settings for the autovacuum are as follows:

autovacuum | on |
Starts the autovacuum subprocess.

autovacuum_analyze_scale_factor | 0.1
| Number of tuple inserts, updates or deletes prior to analyze as a fraction
of reltuples.

autovacuum_analyze_threshold | 50
| Minimum number of tuple inserts, updates or deletes prior to analyze.

autovacuum_freeze_max_age | 200000000
| Age at which to autovacuum a table to prevent transaction ID wraparound.

autovacuum_max_workers | 3
| Sets the maximum number of simultaneously running autovacuum worker
processes.

autovacuum_naptime | 1min
| Time to sleep between autovacuum runs.

autovacuum_vacuum_cost_delay | 20ms
| Vacuum cost delay in milliseconds, for autovacuum.

autovacuum_vacuum_cost_limit | -1
| Vacuum cost amount available before napping, for autovacuum.

autovacuum_vacuum_scale_factor | 0.2
| Number of tuple updates or deletes prior to vacuum as a fraction of
reltuples.

autovacuum_vacuum_threshold | 50

Your assistance will be appreciated.

Machiel Richards

MySQL DBA

Relational Database Consulting

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