Rake task to terminate idle postgresql connections that prevent a database to be dropped

db_terminate_backend.rake

# http://stackoverflow.com/questions/5108876/kill-a-postgresql-session-connection
namespace :db do 
  desc "Fix 'database is being accessed by other users'"
  task :terminate => :environment do
    ActiveRecord::Base.connection.execute <<-SQL
      SELECT 
        pg_terminate_backend(pid) 
      FROM 
        pg_stat_activity 
      WHERE 
        -- don't kill my own connection!
        pid <> pg_backend_pid()
        -- don't kill the connections to other databases
        AND datname = '#{ActiveRecord::Base.connection.current_database}';
    SQL
  end
end

Rake::Task["db:drop"].enhance ["db:terminate"]

Fix for an issue where postgresql doesn't allow a database to be dropped (e.g. “database is being accessed by other users” or “there are N other session(s) using the database”).

Solution from: http://stackoverflow.com/questions/5108876/kill-a-postgresql-session-connection

Drop into db/tasks. It will be run automatically before db:drop. Run manually with rake db:terminate.

Looks promising, since I'm looking for a solution for a similar problem. Unfortunately, my problem occurs in the test environment, and when I try to run the rake db:terminate, it runs in the development environment. Is there an easy way to make this task work in a test enviroment as well?

@plindelauf I'm sure you've fixed your problem meanwhile, but otherwise, try rake db:terminate RAILS_ENV=test.

a star is not really enough for this. thank you ever so much.

+1 just found this and came in very handy

Thanks!!

Awesome. Worked like a charm!