auto truncate/vacuum full

Hi all,

I've got a weird thing on one of my databases this night:

- I've a monthly partition for storing activity logs defined as this:
- mother log table
- one child partition for each month

- Last friday I dumped the last month partition, and tried to truncate it,
which locked lots of queries because the mother table was also locked. So I
killed the TRUNCATE and performed a DELETE on my partition

- Last night the database locked. pg_log full of messages about insert into
the mother table waiting for a lock.

- After about 40min, the waiting queries acquired their locks and ran.

- At the same time, my munin graphs show a decrease of my dbase size, of
about the size of my partition, which pg_(total_)relation_size says has a
zero size now.

- No slow query mentionning truncate nor vacuum full.

- According to pg_stat_user_tables an autovacuum was run on the table just
after the unlock.

So my question are: can the autovacuum daemon perform vacuum full ? Or
another internal postgres process ? Could it come from the TRUNCATE I run
and canceled 4 days before ?

I'm running postgresql-8.3.7

Regards,

--
JC
Ph'nglui mglw'nafh Cthulhu n'gah Bill R'lyeh Wgah'nagl fhtagn!