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!