I backup my PostgreSQL database once a week. One time, during the restore, the restored database was 2.9GB in size, while original database size was 3.7GB. The reason for different sizes is well explained here and that's not a problem.
I back up database using:
pg_dump -U postgres database_name -f backup_file.sql.
To restore the database I use:
psql -U postgres -d target_database -f backup_file.sql.
My question is what is the best way to test and ensure that the restored database has all the data from original database?
Related
I am having some difficulties with restoring the schema of a table. I dumped my Heroku Postgres db and I used pg_restore to restore one table from it into my local db (it has more than 20 tables). It was successfully restored, but I was having issues when I tried to insert new data into the table.
When I opened up my database using psql, I found out that the restored table is available with all the data, but its schema has zero rows. Is there anyway I could import both the table and its schema from the dump? Thank you very much.
This is how I restored the table into my local db:
pg_restore -U postgres --dbname my_db --table=message latest.dump
Edit:
I tried something like this following the official docs, but it just gets blocked and nothing happened. My db is small, no more than a couple of megabytes and the table's schema I am trying to restore has no more than 100 row.
pg_restore -U postgres --dbname mydb --table=message --schema=message_id_seq latest.dump
As a more general answer (I needed to restore a single table from a huge backup), you may want to take a look at this post: https://thequantitative.medium.com/restoring-individual-tables-from-postgresql-pg-dump-using-pg-restore-options-ef3ce2b41ab6
# run the schema-only restore as root
pg_restore -U postgres --schema-only -d new_db /directory/path/db-dump-name.dump
# Restore per table data using something like
pg_restore -U postgres --data-only -d target-db-name -t table_name /directory/path/dump-name.dump
From the Heroku DevCenter here
Heroku Postgres is integrated directly into the Heroku CLI and offers
many helpful commands that simplify common database tasks
You can check here if your environment is correctly configured.
In this way, you can use the Heroku CLI pg:pull command to pull remote data from a Heroku Postgres database to a local database on your machine.
For example:
$ heroku pg:pull HEROKU_POSTGRESQL_MAGENTA mylocaldb --app sushi
I have postgres database with stored data.
Now i want to change my application to run in a container and reading from earlier stored data in postgres database.
But how to create volume with already stored data?
A don't want to lose any data. How to achieve it?
Better to use pg_dump https://postgrespro.com/docs/postgresql/9.6/app-pgdump
You need to dump a database to file at first
pg_dump mydb > db.sql
After your container is running you need to restore this data from file as
psql -d newdb -f db.sql
I am taking the dump of postgres database using "pg_dump database_name > backup.sql". Later on I am doing some modifications in the original database(database_name) and then I am restoring the data from the backup file(backup.sql). But the result is that, the database doesn't gets restored to the original state, instead it adds the original data to the modified data(modified + original).I just want it to restore to the original state, shall i delete all the data from the database before restoring it from the backup file, since it gives the original state of the database. Or is there any other way to do this?
The default format fo pg_dump is plain, so it creates a COPY statement. Hence when you psql backup.sql you just run those copy over existing data. To rewrite data, you should either drop tables first or pg_dump -F c and pg_restore -c.
Warning - in both cases it will destroy old data (this seems what you want though)
-c
--clean Clean (drop) database objects before recreating them. (Unless --if-exists is used, this might generate some harmless error messages, if any objects were not present in the destination database.)
As #Craig Ringer suggests, drop/recreate from backup would be much easier and cleaner. To drop database you run DROP DATABASE au - note that there should be no connected users to success. Then you have to create db: CREATE DATABASE au and run psql -f backup.sql -d au
Take the dump with -c option: pg_dump -c database_name > backup.sql. See pg_dump docs.
I'm totally new to Heroku and Postgres and I'm trying to figure out how to restore and access the Postgres db in Heroku. I do have backup that taken fro pgAdmin III .backup file.
Any help with how to restore the Postgres db in Heroku would be greatly appreciated.
Restore to local database
Load the dump into your local database using the pg_restore tool. If objects exist in a local copy of the database already, you might run into inconsistencies when doing a pg_restore. Pg_restore does not drop all of the objects in the database when loading the dump.
This will usually generate some warnings, due to differences between your Heroku database and a local database, but they are generally safe to ignore.
$ pg_restore --verbose --clean --no-acl --no-owner -h localhost -U myuser -d mydb latest.dump
I'm looking to load a database from a backup.gz. The backup is raw sql generated from pg_dump -U postgres app_development -f backup.gz -Z9.
I've tried dropping the db with psql -Upostgres -c "drop database app_development" but I get:
ERROR: database "app_development" is being accessed by other users
DETAIL: There are 3 other sessions using the database.
The same thing happens when I use dropdb.
I don't want to dump to a non-ascii version so I don't think I can use pg_restore.
Also, I'm not sure if it helps, but all this is happening in docker.