Can I drop & create db while executing pg_restore command? - postgresql

I am trying to execute the following command to restore db in a Docker container:
cmd /c "docker exec -i database-container pg_restore -C -U postgres -d employee -v < C:\\backup\\employee.tar"
But it throws: "pg_restore: error: connection to database "employee" failed: FATAL: database "employee" does not exist" (If I create an empty database with the same name, it is created without any problem).
The reason may be:
When this option is used, the database named with -d is used only to issue the initial DROP DATABASE and CREATE DATABASE commands. All data is restored into the database name that appears in the archive.
So, is it possible to restore db using the same pg_restore command? Or should I modify it by adding drop and create commands to fix the problem?

Finally I concluded to drop and create db before restore. If you have a better solution you are welcome and I will give a try.
docker exec database-container bash -c "dropdb -U postgres employee"
docker exec database-container bash -c "createdb -U postgres employee"
cmd /c "docker exec -i database-container pg_restore -C -U postgres -d employee -v
< C:\\backup\\employee.tar"

You can let pg_restore drop and recreate the database before restoring your backup by providing both parameters --create --clean together.
--create
Create the database before restoring into it. If --clean is also specified, drop and recreate the target database before connecting to it.
See https://www.postgresql.org/docs/12/app-pgrestore.html

Related

Cannot restore Postgresql databases got "database already exists" error

I have take backup by pg_dumpall > test.out
and test.out successfully generated, hence backup completed.
I have used command psql -f test.out postgres for restore
But got following errors with restoring backup:
databases already exists
relation "products" already exists
duplicate key value violates unique constraint "products_pkey"
I actually want to replace the data in the existing db with backup. How to do that?
The problem is that the database you're trying to restore already exists.
You can run a DROP DATABASE database_name command that will delete your existing database and then you can run your test.out file.
Or you can run pgdumpall --clean > test.out and then run the resulting file. The clean flag will make the resulting files have the DROP DATABASE command in them.
Do you use the bellow command ?
psql -h localhost -U [login role] database_name -f /home/database.backup
I think a flow like this might help, because we don't want drop the database each time we call the backup file.
First, we need to create a backup file using the --format=custom [-Fc] to restore it using pg_restore. We can use a connection string postgresql://<user>:<pass>#localhost:5432/<dbname> and replace <user>, <pass>, and <dbname> with your information.
pg_dump -v -Fc \
postgresql://<user>:<pass>#localhost:5432/<dbname> \
> db-20211122-163508.sql
To restore we will call it using --clean [-c] and --create [-C] to drop the database before restoring. Replace <user>, <host>, <port>, and <dbname> with your information.
pg_restore -vcC \
-U <user> \
-h <host> \
-p <port> \
-d <dbname> \
< db-20211122-163508.sql
This way you don't need to use clean when you create the backup file.

clone postgres database with new name

I have a users-production database on 157.157.35.333
I would like to clone it to another host as users-sandbox
here is what I tried:
PRODUCTION_HOST=111.111.11.111
SANDBOX_HOST=222.222.22.222
echo "creating db on sanbox"
psql -h ${SANDBOX_HOST} -U postgres -c "CREATE DATABASE \"users-sandbox\";"
pg_dump -h ${PRODUCTION_HOST} -U postgres -d users-production -F c -b -v | \
pg_restore -C -c -h ${SANDBOX_HOST} -U postgres -d users-sandbox -v
but this creates the database with the old name
how do I create with a new name?
https://www.postgresql.org/docs/current/static/app-pgrestore.html
-d dbname
Connect to database dbname and restore directly into the database.
but!
-C
--create
Create the database before restoring into it. If --clean is also
specified, drop and recreate the target database before connecting to
it.
When this option is used, the database named with -d is used only to
issue the initial DROP DATABASE and CREATE DATABASE commands. All data
is restored into the database name that appears in the archive.
so remove -C from pg_restore arguments...
(formatting of quotes mine)

pg_restore ERROR: “Relation does not exist” and creating new database

I have made a backup of my specific tables that I want to restore into a new database using:
call pg_dump -Fc -h server -d database -U user -p password -v -f dump.sql -t public.table1 -t public.table2
And I have no problems.
I then want to restore the dump by creating a new database with pg_restore using:
call pg_restore --clean --create -d temp -h server -p password -U user dump.sql
This gives me a "database temp does not exist" error. This should have created the database and restored it as far as I understand.
I However then create the "temp" database manually and run:
call pg_restore --clean --create -d temp -h server -p password -U user dump.sql
This follows through, but does not create the tables and gives me an error "relation table1" and "relation table2" does not exist and only creates the corresponding id_sequences for the two tables.
What I actually want is to not have to manually create the new database and that all tables in the backup is restored into a brand new database via pg_restore using:
call pg_restore --clean --create -d temp -h server -p password -U user dump.sql
as I understand it.
In order to create the database temp, pg_restore needs to be connected to a different database first.
So it won't do to use -d temp; you must specify an existing database, typically postgres.
pg_restore will connect to that database, issue CREATE DATABASE temp, connect to temp and proceed to restore the data.

Ignoring a table in pg_dump and restore

This is what I currently do to copy a database from my local machine to a remote server.
Dump local database:
pg_dump dbname --clean -U postgres > dumpfile
Restore remote database:
psql --single-transaction dbname -U postgres < dumpfile
This does a perfect replication.
How do I modify this to ignore particular table names, both in the source and destination?
This will be useful for tables that log website visits. I want to retain my existing remote visit logs, while ignoring my local "visit" logs (which is just me visiting my own website locally).
Using the -t switch, you can be selective about what tables to include:
pg_dump <your switches> -t my_schema.awesome* -f backup.bat postgres
Which will only include those tables.
Likewise, the -T switch will do the opposite -- dump everything but the tables you specified:
pg_dump <your switches> -T my_schema.lame* -f backup.bat postgres
You can use each switch multiple times as well:
pg_dump <your switches> \
-t my_schema.awesome* \
-t my_schema.amazing* \
-t my_schema.great -f backup.bat postgres
When you restore, it won't bother trying to restore something it didn't back up, so that part should be handled somewhat natively.

Restore a postgres backup file using the command line?

Locally, I use pgadmin3. On the remote server, however, I have no such luxury.
I've already created the backup of the database and copied it over, but is there a way to restore a backup from the command line? I only see things related to GUI or to pg_dumps.
There are two tools to look at, depending on how you created the dump file.
Your first source of reference should be the man page pg_dump as that is what creates the dump itself. It says:
Dumps can be output in script or
archive file formats. Script dumps are
plain-text files containing the SQL
commands required to reconstruct
the database to the state it was
in at the time it was saved. To
restore from such a script, feed it to
psql(1). Script files can be used
to reconstruct the database even
on other machines and other
architectures; with some modifications
even on other SQL database products.
The alternative archive file formats
must be used with pg_restore(1) to
rebuild the database. They allow
pg_restore to be selective about what
is restored, or even to reorder the
items prior to being restored. The
archive file formats are designed to
be portable across architectures.
So depends on the way it was dumped out. If using Linux/Unix, you can probably figure it out using the excellent file(1) command - if it mentions ASCII text and/or SQL, it should be restored with psql otherwise you should probably use pg_restore.
Restoring is pretty easy:
psql -U username -d dbname < filename.sql
-- For Postgres versions 9.0 or earlier
psql -U username -d dbname -1 -f filename.sql
or
pg_restore -U username -d dbname -1 filename.dump
Check out their respective manpages - there's quite a few options that affect how the restore works. You may have to clean out your "live" databases or recreate them from template0 (as pointed out in a comment) before restoring, depending on how the dumps were generated.
create backup
pg_dump -h localhost -p 5432 -U postgres -F c -b -v -f
"/usr/local/backup/10.70.0.61.backup" old_db
-F c is custom format (compressed, and able to do in parallel with -j N) -b is including blobs, -v is verbose, -f is the backup file name.
restore from backup
pg_restore -h localhost -p 5432 -U postgres -d old_db -v
"/usr/local/backup/10.70.0.61.backup"
important to set -h localhost - option
You might need to be logged in as postgres in order to have full privileges on databases.
su - postgres
psql -l # will list all databases on Postgres cluster
pg_dump/pg_restore
pg_dump -U username -f backup.dump database_name -Fc
switch -F specify format of backup file:
c will use custom PostgreSQL format which is compressed and results in smallest backup file size
d for directory where each file is one table
t for TAR archive (bigger than custom format)
-h/--host Specifies the host name of the machine on which the server is running
-W/--password Force pg_dump to prompt for a password before connecting to a database
restore backup:
pg_restore -d database_name -U username -C backup.dump
Parameter -C should create database before importing data. If it doesn't work you can always create database eg. with command (as user postgres or other account that has rights to create databases) createdb db_name -O owner
pg_dump/psql
In case that you didn't specify the argument -F default plain text SQL format was used (or with -F p). Then you can't use pg_restore. You can import data with psql.
backup:
pg_dump -U username -f backup.sql database_name
restore:
psql -d database_name -f backup.sql
POSTGRESQL 9.1.12
DUMP:
pg_dump -U user db_name > archive_name.sql
put the user password and press enter.
RESTORE:
psql -U user db_name < /directory/archive.sql
put the user password and press enter.
Below is my version of pg_dump which I use to restore the database:
pg_restore -h localhost -p 5432 -U postgres -d my_new_database my_old_database.backup
or use psql:
psql -h localhost -U postgres -p 5432 my_new_database < my_old_database.backup
where -h host, -p port, -u login username, -d name of database
Backup and restore with GZIP
For larger size database this is very good
backup
pg_dump -U user -d mydb | gzip > mydb.pgsql.gz
restore
gunzip -c mydb.pgsql.gz | psql dbname -U user
https://www.postgresql.org/docs/14/backup-dump.html
This worked for me:
pg_restore --verbose --clean --no-acl --no-owner --host=localhost --dbname=db_name --username=username latest.dump
Backup: $ pg_dump -U {user-name} {source_db} -f {dumpfilename.sql}
Restore: $ psql -U {user-name} -d {desintation_db} -f {dumpfilename.sql}
try this:
psql -U <username> -d <dbname> -f <filename>.sql
Restore DB psql from .sql file
Backup & Restore
This is the combo I'm using to backup, drop, create and restore my database (on macOS and Linux):
sudo -u postgres pg_dump -Fc mydb > ./mydb.sql
sudo -u postgres dropdb mydb
sudo -u postgres createdb -O db_user mydb
sudo -u postgres pg_restore -d mydb < ./mydb.sql
Misc
-Fc will compress the database (Format custom)
List PostgreSQL users: sudo -u postgres psql -c "\du+"
You may want to add hostname and date to ./mydb.sql, then change it by:
./`hostname`_mydb_`date +"%Y%m%d_%H%M"`.sql
If you create a backup using pg_dump you can easily restore it in the following way:
Open command line window
Go to Postgres bin folder. For example: cd "C:\ProgramFiles\PostgreSQL\9.5\bin"
Enter the command to restore your database. For example: psql.exe -U postgres -d YourDatabase -f D:\Backup\.sql
Type password for your postgres user
Check the restore process
I didnt see here mentions about dump file extension (*.dump).
This solution worked for me:
I got a dump file and needed to recover it.
First I tried to do this with pg_restore and got:
pg_restore: error: input file appears to be a text format dump. Please use psql.
I did it with psql and worked well:
psql -U myUser -d myDataBase < path_to_the_file/file.dump
1. Open the Terminal.
2. Backup your database with following command
your postgres bin -> /opt/PostgreSQL/9.1/bin/
your source database server -> 192.168.1.111
your backup file location and name -> /home/dinesh/db/mydb.backup
your source db name -> mydatabase
/opt/PostgreSQL/9.1/bin/pg_dump --host '192.168.1.111' --port 5432 --username "postgres" --no-password --format custom --blobs --file "/home/dinesh/db/mydb.backup" "mydatabase"
3. Restore mydb.backup file into destination.
your destination server -> localhost
your destination database name -> mydatabase
Create database for restore the backup.
/opt/PostgreSQL/9.1/bin/psql -h 'localhost' -p 5432 -U postgres -c "CREATE DATABASE mydatabase"
Restore the backup.
/opt/PostgreSQL/9.1/bin/pg_restore --host 'localhost' --port 5432 --username "postgres" --dbname "mydatabase" --no-password --clean "/home/dinesh/db/mydb.backup"
1) Open psql terminal.
2) Unzip/ untar the dump file.
3) Create an empty database.
4) use the following command to restore the .dump file
<database_name>-# \i <path_to_.dump_file>
To restore a dump file
psql -d [Dbname] -U [UserName] -p 5432 < [FileLocation]
To restore a .SQL file
pg_restore -U [Username] -d [Dbname] -1 [FileLocation]
If you get user authentication errors, go to the file pg_hba.conf which is in PSQL/data folder in your program files, and change the "METHOD" to "Trust".
Restart you psql serive in windows services(Win + R --> services.msc).
try:
pg_restore -h localhost -p 5432 -U <username> -d <dbname> -1 <filename>
Restoring a postgres backup file depends on how did you take the backup in the first place.
If you used pg_dump with -F c or -F d you need to use pg_restore otherwise you can just use
psql -h localhost -p 5432 -U postgres < backupfile
9 ways to backup and restore postgres databases
As below link said, you can use psql command for restoring the dump file:
https://www.postgresql.org/docs/8.1/static/backup.html#BACKUP-DUMP-RESTORE
psql dbname < infile
if you need to set username just add the username after the command like:
psql dbname < infile username
Sorry for the necropost, but these solutions did not work for me. I'm on postgres 10. On Linux:
I had to change directory to my pg_hba.conf.
I had to edit the file to change method from peer to md5 as stated here
Restart the service: service postgresql-10 restart
Change directory to where my backup.sql was located and execute:
psql postgres -d database_name -1 -f backup.sql
-database_name is the name of my database
-backup.sql is the name of my .sql backup file.
Try to see if the following commands can help you:
sudo su - yourdbuser
psql
\i yourbackupfile
If you have a backup SQL file then you can easily Restore it.
Just follow the instructions, given in the below
1. At first, create a database using pgAdmin or whatever you want (for example my_db is our created db name)
2. Now Open command line window
3. Go to Postgres bin folder. For example: cd "C:\ProgramFiles\PostgreSQL\pg10\bin"
4. Enter the following command to restore your database: psql.exe -U postgres -d my_db -f D:\Backup\backup_file_name.sql
Type password for your postgres user if needed and let Postgres to do its work. Then you can check the restore process.
The shortest way with no password prompt
psql "postgresql://<db_user>:<db_pass>#<ip>:<port>/<db_name>" < "backup.sql"
If you are using Windows OS
psql.exe "postgresql://<db_user>:<db_pass>#<ip>:<port>/<db_name>" < "backup.sql"
I was having authentication problems running pg_dump, so I moved my dump file
mv database_dump /tmp
into the temp directory and then ran
su -u postgres
cd /tmp
pg_restore database_dump
If you have a large database dump, you may just want to create another directory where your current user and the postgres user can access and putting the database dump file into that.
Backup==>
Option1: To take backup along with password in cmd
1.PGPASSWORD="mypassword" pg_dump -U postgres -h localhost --inserts mydb>mydb.sql
Option2: To take backup without password in cmd
2. pg_dump -U postgres -h localhost --inserts mydb>mydb.sql
Option3: To take backup as gzip(if database is huge)
3. pg_dump -U postgres -h localhost mydb --inserts | gzip > mydb.gz
Restore:
1. psql -h localhost -d mydb -U postgres -p 5432 < mydb.sql
This solution only works for Windows.
First, ensure you have already added the postgres bin folder to the "Path" environment variable (in my case this folder is C:\Program Files\PostgreSQL\12\bin).
Then, open the Windows command interpreter (cmd), go to the folder where you have the .sql file and execute this command:
pg_restore -U userName -d database-1 backupfile.sql
For example:
pg_restore -U sam -d SamDataBase -1 SamDataBaseBackup.sql
(It can ask you for the password of the user so ensure to type it correctly and then click enter)
Pura vida!
If you have created a new database named mydb, To restore a .sql dump to that database with psql,
psql --file=dump.sql --username=postgres --host=localhost --port=5432 mydb
the password will be prompted by psql
The connection options are
-h, --host=HOSTNAME database server host or socket directory (default: "/var/run/postgresql")
-p, --port=PORT database server port (default: "5432")
-U, --username=USERNAME database user name (default: "xyz")
-w, --no-password never prompt for password
-W, --password force password prompt (should happen automatically)
If you are using docker, this answer may be helpful.
Start the container
docker start <postgres_container_id>
Access bash inside container
docker exec -it <postgres_container_id> bash
Copy the .tar backup file to docker container (In another window)
docker cp postgres_dump.tar <postgres_container_id>:/
Restore the backup
pg_restore -c -U <postgres-user> -d <password> -v "postgres_dump.tar" -W
Enter password
Save and restore the exact same state with compressed dump
Other answers gave all the key bits separately, but hopefully this will provide be the "just works save and restore to exact state" command pair.
Dump to file mydb.psql:
PGPASSWORD=mypassword pg_dump -U my_username -h localhost mydb -Fc -f mydb.psql
Restore:
PGPASSWORD=mypassword pg_restore -U my_username -h localhost \
--clean -d mydb -v mydb.psql
Some of the flags:
-Fc: Format Compressed, as opposed to plaintext.
file tmp.psql says:
tmp.psql: PostgreSQL custom database dump - v1.14-0
--clean: destroy the target DB before restoring it, thus returning to the exact same pristine state.
Any data created after the dump will be lost.
PGPASSWORD, -U and -h can of course be modified depending on your login method, e.g. without PGPASSWORD you're prompted for a password, and none of those are needed if you set up peer auth locally.
Tested on Ubuntu 22.04, PostgreSQL 14.5.
If you want to backup your data or restore data from a backup, you can run the following commands:
To create backup of your data, go to your postgres \bin\ directory like C:\programfiles\postgres\10\bin\ and then type the following command:
pg_dump -FC -U ngb -d ngb -p 5432 >C:\BACK_UP\ngb.090718_after_readUpload.backup
To restore data from a backup, go to your postgres \bin\ directory like C:\programfiles\postgres\10\bin\ and then type below command:
C:\programFiles\postgres\10\bin> pg_restore -Fc -U ngb -d ngb -p 5432 <C:\ngb.130918.backup
Please make sure that the backup file exists.
Follow these 3 steps :
start postgres server - sudo systemctl start postgresql
enable same - sudo systemctl enable postgresql
restore command - pg_restore -h localhost -p 5432 -U postgres -d old_db
assuming that the dump is there in the same directory
Links :
https://www.postgresqltutorial.com/postgresql-restore-database
https://askubuntu.com/questions/50621/cannot-connect-to-postgresql-on-port-5432