Dear all, Just letting you know that making the autovacuum policy more aggressive seems to have fixed the problem. It's been 4 days now and everything is running smoothly. Just a reminder, what I changed was : autovacuum_vacuum_scale_factor = 0.01 autovacuum_analyze_scale_factor = 0.005 making autovacuum run at 1% instead of 20% (the dafault) and the analyze run at 0,5% instead of 10%. Maybe it's more aggressive than needed... I will monitor and post back. Thank you all for your help. -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance