To incrementally backup the DB to an `.sql` file, you can run:
```bash
-docker exec -t FOLDERNAME_postgres_1 pg_dumpall -c -U lemmy > lemmy_dump_`date +%Y-%m-%d"_"%H_%M_%S`.sql
+docker-compose exec postgres pg_dumpall -c -U lemmy > lemmy_dump_`date +%Y-%m-%d"_"%H_%M_%S`.sql
```
### A Sample backup script
```bash
#!/bin/sh
# DB Backup
-ssh MY_USER@MY_IP "docker exec -t FOLDERNAME_postgres_1 pg_dumpall -c -U lemmy" > ~/BACKUP_LOCATION/INSTANCE_NAME_dump_`date +%Y-%m-%d"_"%H_%M_%S`.sql
+ssh MY_USER@MY_IP "docker-compose exec postgres pg_dumpall -c -U lemmy" > ~/BACKUP_LOCATION/INSTANCE_NAME_dump_`date +%Y-%m-%d"_"%H_%M_%S`.sql
# Volumes folder Backup
rsync -avP -zz --rsync-path="sudo rsync" MY_USER@MY_IP:/LEMMY_LOCATION/volumes ~/BACKUP_LOCATION/FOLDERNAME
docker exec -i FOLDERNAME_postgres_1 psql -U lemmy -c "alter user lemmy with password 'bleh'"
```
+### Changing your domain name
+
+If you haven't federated yet, you can change your domain name in the DB. **Warning: do not do this after you've federated, or it will break federation.**
+
+Get into `psql` for your docker:
+
+`docker-compose exec postgres psql -U lemmy`
+
+```
+-- Post
+update post set ap_id = replace (ap_id, 'old_domain', 'new_domain');
+update post set url = replace (url, 'old_domain', 'new_domain');
+update post set body = replace (body, 'old_domain', 'new_domain');
+update post set thumbnail_url = replace (thumbnail_url, 'old_domain', 'new_domain');
+
+delete from post_aggregates_fast;
+insert into post_aggregates_fast select * from post_aggregates_view;
+
+-- Comments
+update comment set ap_id = replace (ap_id, 'old_domain', 'new_domain');
+update comment set content = replace (content, 'old_domain', 'new_domain');
+
+delete from comment_aggregates_fast;
+insert into comment_aggregates_fast select * from comment_aggregates_view;
+
+-- User
+update user_ set actor_id = replace (actor_id, 'old_domain', 'new_domain');
+update user_ set avatar = replace (avatar, 'old_domain', 'new_domain');
+
+delete from user_fast;
+insert into user_fast select * from user_view;
+
+-- Community
+update community set actor_id = replace (actor_id, 'old_domain', 'new_domain');
+
+delete from community_aggregates_fast;
+insert into community_aggregates_fast select * from community_aggregates_view;
+```
+
## More resources
- https://stackoverflow.com/questions/24718706/backup-restore-a-dockerized-postgresql-database