I've upgraded my CentOS 5.5 VM to: postgresql-libs-8.4.4-1PGDG.rhel5 postgresql-devel-8.4.4-1PGDG.rhel5 postgresql-8.4.4-1PGDG.rhel5 postgresql-contrib-8.4.4-1PGDG.rhel5 postgresql-docs-8.4.4-1PGDG.rhel5 postgresql-server-8.4.4-1PGDG.rhel5 postgresql-plperl-8.4.4-1PGDG.rhel5 and then have loaded my backup and then run my cleanup script (source below) and it would stuck: pref=> \i bin/clean-phpbb-forum.sql START TRANSACTION DELETE 6 CREATE TABLE CREATE TABLE INSERT 0 26699 INSERT 0 129903 [... and here nothing happens for minutes....] And in the /var/lib/pgsql/data/pg_log/postgresql-Mon.log see (probably because of the many inserts?) LOG: autovacuum launcher started LOG: database system is ready to accept connections LOG: statement: start transaction; LOG: statement: delete from phpbb_users where user_type=1 and user_inactive_reason=1 and user_lastvisit=0 and age(to_timestamp(user_regdate))>interval '3 days'; LOG: statement: create temp table old_topics (topic_id integer) on commit delete rows; LOG: statement: create temp table old_posts (post_id integer) on commit delete rows; LOG: statement: insert into old_topics select topic_id from phpbb_topics where forum_id=5 and topic_poster=1 and age(to_timestamp(topic_time))>interval '7 days'; LOG: statement: insert into old_posts select p.post_id from phpbb_posts p, old_topics t where p.forum_id=5 and p.poster_id=1 and p.topic_id=t.topic_id; LOG: statement: delete from phpbb_posts where post_id in (select post_id from old_posts); LOG: checkpoints are occurring too frequently (29 seconds apart) HINT: Consider increasing the configuration parameter "checkpoint_segments". LOG: checkpoints are occurring too frequently (29 seconds apart) Then after some minutes waiting, I've pressed ctrl-Z on the pgsql and then "fg" and this has waken PostgreSQL up for some reason: [1]+ Stopped psql afarber@centos:~> fg psql DELETE 129903 DELETE 26699 UPDATE 1 UPDATE 1 UPDATE 1 UPDATE 1 COMMIT Could it be that my script is somehow making PostgreSQL hang? (or wait for some input?): cat ~/bin/clean-phpbb-forum.sql start transaction; delete from phpbb_users where user_type=1 and user_inactive_reason=1 and user_lastvisit=0 and age(to_timestamp(user_regdate))>interval '3 days'; create temp table old_topics (topic_id integer) on commit delete rows; create temp table old_posts (post_id integer) on commit delete rows; insert into old_topics select topic_id from phpbb_topics where forum_id=5 and topic_poster=1 and age(to_timestamp(topic_time))>interval '7 days'; -- select count(topic_id) as "old topics:" from old_topics; insert into old_posts select p.post_id from phpbb_posts p, old_topics t where p.forum_id=5 and p.poster_id=1 and p.topic_id=t.topic_id; -- select count(post_id) as "old posts:" from old_posts; delete from phpbb_posts where post_id in (select post_id from old_posts); delete from phpbb_topics where topic_id in (select topic_id from old_topics); update phpbb_config set config_value = (select count(topic_id) from phpbb_topics) where config_name = 'num_topics'; update phpbb_config set config_value = (select count(post_id) from phpbb_posts) where config_name = 'num_posts'; update phpbb_users set user_posts = (select count(post_id) from phpbb_posts where poster_id=1) where user_id = 1; update phpbb_forums set forum_posts = (select count(post_id) from phpbb_posts), forum_topics = (select count(topic_id) from phpbb_topics), forum_topics_real = (select count(topic_id) from phpbb_topics) where forum_id = 5; commit Thank you for any insights Alex PS: I haven't modified postgresql.conf or other conf files besides logging: # diff postgresql.conf{.OLD,} 353c353 < #log_statement = 'none' # none, ddl, mod, all --- > log_statement = 'all' # none, ddl, mod, all # grep checkpoint postgresql.conf #checkpoint_segments = 3 # in logfile segments, min 1, 16MB each #checkpoint_timeout = 5min # range 30s-1h #checkpoint_completion_target = 0.5 # checkpoint target duration, 0.0 - 1.0 #checkpoint_warning = 30s # 0 disables #log_checkpoints = off -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general