PG Dump/Restore

pg-dump-restore

PostgreSQL database server provides pg_dump and psql utilities for backup and restore databases. This article will describe various ways to use of pg_dump command to backup database. Also you will learn how to restore datbase backup.

Backup and Restore Database in PostgreSQL
Below is some connections options which you can use for connecting remote server or authenticated server with all queries given in this article.

-d, –dbname=DBNAME database name
-h, –host=HOSTNAME database server hostname or ip
-p, –port=PORT database server port number (default: 5432)
-U, –username=NAME connect as specified database user
-W, –password force password prompt
–role=ROLENAME do SET ROLE before dump
1. Backup and Restore Single Database
Backup: single database in PostgreSQL. Replace your actual database name with mydb.

$ pg_dump -U postgres -d mydb > mydb.pgsql
Restore: single database backup in PostgreSQL.

$ psql -U postgres -d mydb < mydb.pgsql
2. Backup and Restore All Databases
Backup: all databases in PostgreSQL using pg_dumpall utility.

$ pg_dumpall -U postgres > alldbs.pgsql
Restore: all database backup using following command.

$ psql -U postgres < alldbs.pgsql
3. Backup and Restore Single Table
Backup: a single table named mytable from mydb database.

$ pg_dump -U postgres -d mydb -t mytable > mydb-mytable.pgsql
Restore: single table backup to database. Make sure your backup file contains only single table backup which you want to restore.

$ psql -U postgres -d mydb < mydb-mytable.pgsql
4. Compressed Backup and Restore Database
Backup: PostgreSQL database in compressed format.

$ pg_dump -U postgres -d mydb | gzip > mydb.pgsql.gz
Restore: database from compressed backup file directly.

$ gunzip -c mydb.pgsql.gz | psql -U postgres -d mydb
5. Split Backup in Multiple Files and Restore
Backup: PostgreSQL database and split backup in multiple files of specified size. It helps us to backup a large database and transfer to other host easily. As per below example it will split backup files of 100mb in size.

$ pg_dump -U postgres -d mydb | split -b 100m – mydb.pgsql
Restore: database backup from multiple splited backup files.

$ cat mydb.pgsql* | psql -U postgres -d mydb
Backup: database in compressed splited files of specified size.

$ pg_dump -U postgres -d mydb | gzip | split -b 100m – mydb.pgsql.gz
Restore: database from multiple files of compressed files.

$ cat mydb.pgsql.gz* | gunzip | psql -U postgres -d mydb