Database locks

select * from pg_stat_activity where waiting='t';

Fix the lock:

select pg_cancel_backend(pid int)

Where "pid int" is the pid you find with pg_stat_activity.

Sources:

• http://www.postgresql.org/docs/9.2/static/functions-admin.html
• http://wiki.postgresql.org/wiki/Lock_Monitoring
• http://chrismiles.info/systemsadmin/databases/articles/viewing-current-postgresql-queries/