We are migrating some products, one of the steps is to migrate the product databases.
I have steps to
export the existing DB pg_dump --no-owner --clean --blobs --no-privileges -U dbuser old_dbname -f bkpfile.sql
import the dump to a different DB psql -U dbuser2 new_dbname -f bkpfile.sql
The problem is the old database contains statement COMMENT ON DATABASE old_dbname IS 'Rxxxxx';
The new DB user must not have permissions on the old database and imho it's not good to refer the old database name anyway in the dump.
Is there a way to create a complete DB dump without the COMMENT ON DATABASE statement?
Edit:
PostgreSQL 9.6
Steps to reproduce:
CREATE DATABASE testdb;
COMMENT ON DATABASE testdb IS 'some comment';
CREATE TABLE xx (id int);
and then dump the database, the dump contains reference to the database name COMMENT ON DATABASE testdb IS 'some comment'; which prevents importing the backup to a new database
pg_dump --no-owner --clean --blobs --no-privileges testdb
We could manually remove the comment statement or filter the comment using different tools (grep), but manual intervention or text-based filtering on top of the backup could cause data corruption.
This comment is only dumped in PostgreSQL versions below v11. See this entry in the release notes:
pg_dump and pg_restore, without --create, no longer dump/restore database-level comments and security labels; those are now treated as properties of the database.
9.6 will go out of support soon anyway, so this is a good opportunity to upgrade.
Related
After making some schema change in table message in postgresql 13 database, the table is backed up in pgadmin4 in a file named message.sql. The schema change needs to be populated in another database. What I did is to drop the table message in that database. But I have hard time to re-create table message from the backup file messages.sql (not using CREATE table message ....). I use pg_restore to restore data but was not successful for re-creating table schema. Here is command I tried with no luck:
pg_restore --data-only -h localhost -U postgres -W -d dynamo -t messages /home/download/messages.sql
pg_restore --clean -h localhost -U postgres -W -d dynamo -t messages /home/download/messages.sql
I also tried to create an blank table (no column) called messages in the database and repeated above command, again without luck.
Here is how a new table is added to the current database:
backup the current db on the server with pg_dump
create the new database on dev PC with addition of new table
On dev PC, use pgadmin to restore the backup file in step 1 to new database created in step 2.
backup in pgadmin and create a .backup file for db in step 3.
on server, use pg_restore to overwrite the current db with new database backup file created in step 4:
pg_restore --clean -U postgres --dbname=mydb -W -h localhost --verbose /home/download/mydb.backup
open psql terminal to verify the new table
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 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 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.
I search for a while to find this answer but with no luck.
The situation:
I have Postgresql currently running on my production environment. I am preparing to scale my database and move it to a large server instance. I made the mistake of setting up the initial database with the postgres user who has all permissions, and I would like the new database to be controlled by a custom user I have created. ie The current database's owner is postgres, and I want the new database owner to be pooper.
To dump, I am running:
pg_dump -d database_name > database_name.sql
To restore on separate machine, I am running:
psql database_name < database_name.sql
If the user is the same, ie both postgres, then it will work just fine, but when switching users, my app does not load correctly. Is there a secret to the madness. Nothing stood out to me.
My system:
Debian Wheezy
Postgresql 9.1
Postgis Extension
pg_dump with the --no-owner flag (see pg_dump --help)
Create the new db with the new owner CREATE DATABASE foo OWNER pooper;,
Load via psql -U pooper -d database_name -f database_name.sql.