I'm trying to backup up an entire postgres database and restore it properly, however I am seeing a list of errors when trying to restore the backup.
I am using pg_dump to create a backup sql file. (I have a .pgpass file for password)
sudo -u postgres pg_dump -d db-w > backup.sql
When I try to restore the database with:
sudo -u postgres psql db < backup.sql
I get a list of errors like:
ERROR: duplicate key value violates unique constraint
ERROR: multiple primary keys for table
ERROR: relation <relation> already exists
ERROR: trigger <trigger> for relation <relation> already exist
I haven't made any changes to the database. I simply performed a backup and restore the backup right after.
What am I doing wrong?
your restoring on an existing database, if you want and sure to replace database with the backup you can use option --clean and --create
-c, --clean
Clean (drop) database objects before recreating them. (This might
generate some harmless error messages, if any objects were not
present in the destination database.)
-C, --create
Create the database before restoring into it. If --clean is also
specified, drop and recreate the target database before connecting
to it.
Related
I try dumping tables from a production environment to a dev one. However, when dumping and restoring this table, using the following command:
pg_restore --no-owner --no-acl --clean --if-exists -d database dump_file.dump
I get an error stating that I can't drop that table unless I use something like CASCADE (i.e. dropping all other tables that depend on that one). Is there a way to determine the tables to be dropped? is there a way of maybe state in the pg_dump command to dump the table I'm looking to dump and all related tables ?
Here's the error raised:
pg_restore: while PROCESSING TOC:
pg_restore: from TOC entry 4066; 2606 30526 CONSTRAINT table1 pkey user
pg_restore: error: could not execute query: ERROR: cannot drop constraint pkey on table public.table1 because other objects depend on it
DETAIL: constraint id_fkey on table public.dag depends on index public.pkey
constraint id_fkey on table public.dag depends on index public.pkey
HINT: Use DROP ... CASCADE to drop the dependent objects too...
You have a table on the dev database that has a pkey that is dependent and therefore can not be dropped before the restore. This is proper behavior.
I am not seeing dumping/restoring a particular table. You are dumping/restoring the entire database.
If you want recreate the production database as a dev one then do:
pg_restore -C --no-owner --no-acl --clean --if-exists -d postgres dump_file.dump
The -C with --clean will DROP DATABASE db_name and then rebuild it from scratch by connecting to the database postgres to do the DROP/CREATE db_name and then connect to db_name to load the rest of the objects.
This is the best way to clean out cruft and start at a consistent state.
UPDATE
Update your question with the pg_dump command so it is evident what you are doing.
If you want to see whether a particular table has dependencies, in the original database use psql and do \d the_table to see what the dependencies to and from the table are. If you tell pg_dump to dump a single table it will dump just that table. It will not follow dependencies and dump those also. That is up to you to do.
Look into using a schema management tool to do your changes/migrations. I use Sqitch for this.
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 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 have created a backup of my database using the following commands:
pg_dump -Fc mydatabase > db.dump
I can restore this backup using the pg_restore -C by first creating the database outlined in the backup file and then connecting to it. However, when I try to restore the backup with pg_restore without the -C into a newly created database nothing happens. I run the following command:
pg_restore -d newdatabase
When I attempt to view all columns of newdatabase I get:
ERROR: relation "newdatabase" does not exist
I am essentially doing what the documentation told me:
Any help as to why this is happening or how to restore into a newly created database using pg_restorewould be great.
EDIT:
I just checked if newdatabase exists and it does:
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.