Django PostgreSQL Copy
django-pg-copy provides Django management commands for backing up and restoring PostgreSQL databases. These were developed for copying production databases to development, to allow developers to share images with one another, or bring local development databases up to date. It can also be handy for creating different local databases for different branches, and for only creating one migration after tweaking models to get them the way they need to be.
We also use it with Jenkins to automatically back up production, and restore to a staging database environment, so we can test new migrations repeatedly to ensure they'll work when we run them in production.
pip install django-pg-copy
'pg_copy', to your
INSTALLED_APPS list. It is recommended that it is used in all environments (development, production) so that you can use it against different instances of your database.
PG_COPY_BACKUP_PATH = 'db_backup'
By default, PostgreSQL backups will be stored in a directory called
db_backup where you run the command. This setting will override that location.
It is also recommended to add this path to your
.gitignore file, if the path falls under your version control repository.
--database: The database defined in the DATABASES settings to backup from or restore to.
--db-override: A value to override the db argument sent to psql.
--host-override: A value to override the host argument sent to psql.
--pg-home: The path to the PostgreSQL installation, if it is not on your path.
-f: The filename to backup to, or restore from.
-i: Excludes the table completely during the backup file creation. Can pass multiple tables:
-i bigtable1 -i bigtable2
-e: Excludes the table data during the backup file creation. Can pass multiple tables:
-e bigtable1 -e bigtable2
--no-confirm: Restores the database without confirmation: be careful! (pg_restore only)
python manage.py pg_backup --settings=config.settings.production --database=default --filename=my_backup.sqlc
This command will create a backup in the same directory as
my_backup.sqlc using the
default settings from
DATABASES using the Django settings file located at
python manage.py pg_backup
This command will create a backup in the directory
./db_backup/ (or the directory you specified with
[timestamp].sqlc using the
default settings from
DATABASES using the default Django settings file resolved by
python manage.py pg_backup -i bigtable1 -i bigtable2
This will do the same as the previous command, but omit the tables named
python manage.py pg_backup -e bigtable1 -e bigtable2
This will do the same as the previous command, but include the table structure without any data for the tables named
python manage.py pg_restore
This command will provide a list of backup files in
PG_COPY_BACKUP_PATH that can be restored. After selecting a backup file, it will confirm that the user wants to overwrite the destination database by showing which server and database will be overwritten from the settings. Here's what it will look like:
(venv) [django-project]$ ./manage.py pg_restore There are 8 backup files in '/var/dev/username/django-project/db_backup'. Which would you like to restore? 1: 2020-05-27-13-33-38.sqlc 2: 2020-05-10-09-07-45.sqlc 3: 2020-05-11-13-05-49.sqlc 4: 2020-07-14-15-21-22.sqlc 5: 2020-05-15-08-31-59.sqlc 6: 2020-06-11-13-11-00.sqlc 7: 2020-06-02-13-28-09.sqlc 8: 2020-05-27-14-54-15.sqlc Enter number of the file to restore: 4 About to restore 'django_project_db' on host 'localhost' from the file: '/var/dev/username/django-project/db_backup/2020-07-14-15-21-22.sqlc'. THIS WILL OVERWRITE THE DATABASE. Type "yes" to start the restore [no]: yes
python manage.py pg_restore --filename=my_file.sqlc --no-confirm
This command will read the file
my_file.sqlc and confirm that the user wants to overwrite the destination database by showing which server and database will be overwritten from the settings.
Errors Displayed During
When restoring, PostgreSQL's
pg_restore command will output some warnings. I haven't figured out a command line option to make these warnings disappear, but they can be safely ignored if you read them. Here is an example of what these errors may look like:
pg_restore: [archiver (db)] Error while PROCESSING TOC: pg_restore: [archiver (db)] Error from TOC entry 1; 3079 13792 EXTENSION plpgsql pg_restore: [archiver (db)] could not execute query: ERROR: must be owner of extension plpgsql Command was: DROP EXTENSION IF EXISTS plpgsql; pg_restore: [archiver (db)] Error from TOC entry 6; 2615 2200 SCHEMA public postgres pg_restore: [archiver (db)] could not execute query: ERROR: must be owner of schema public Command was: DROP SCHEMA IF EXISTS public; pg_restore: [archiver (db)] could not execute query: ERROR: schema "public" already exists Command was: CREATE SCHEMA public;
This package is maintained by the staff of Wharton Research Data Services. We are thrilled that The Wharton School allows us a certain amount of time to contribute to open-source projects. We add features as they are necessary for our projects, and try to keep up with Issues and Pull Requests as best we can. Due to constraints of time (our full time jobs!), Feature Requests without a Pull Request may not be implemented, but we are always open to new ideas and grateful for contributions and our package users.