Rails + Postgres drop error: database is being accessed by other users

Question

I have a rails application running over Postgres.

I have two servers: one for testing and the other for production.

Very often I need to clone the production

Answer 1

Solution

Bash script

ENV=development

# restart postgresql
brew services restart postgresql

# get name of the db from rails app
RAILS_CONSOLE_COMMAND="bundle exec rails c -e $ENV"
DB_NAME=$(echo 'ActiveRecord::Base.connection_config[:database]' | $RAILS_CONSOLE_COMMAND | tail -2 | tr -d '\"')

# delete all connections to $DB_NAME
for pid in $(ps -ef | grep $DB_NAME | awk {'print$2'})
do
   kill -9 $pid
done

# drop db
DISABLE_DATABASE_ENVIRONMENT_CHECK=1 RAILS_ENV=$ENV bundle exec rails db:drop:_unsafe

Answer 2

Rails is likely connecting to the database to drop it but when you log in via phppgadmin it is logging in via the template1 or postgres database, thus you are not affected by it.

Answer 3

Let your application close the connection when it's done. PostgreSQL doesn't keep connections open , it's the application keeping the connection.

Answer 4

This worked for me (rails 6): rake db:drop:_unsafe

I think we had something in our codebase that initiated a db connection before the rake task attempted to drop it.