How to Create Database dump Backup and restore postgresql

To create dump file as a backup from postgresql follow the simple commands below:
pg_dump is an effective tool to backup postgres database. It creates a *.sql file with CREATE TABLE, ALTER TABLE, and COPY SQL statements of source database. To restore these dumps psql command is enough.
 
1: login to your server through ssh
and run the commands:

2: pg_dump -U {user-name} {source_db} -f > {dumpfilename.sql}
In my case it will be 
    pg_dump -U shahmeer firstdb > firstdb.sql

Backup all postgres databases
To backup all databases, list out all the available databases;
login as postgres /psql user:
# su - postgres
#psql -l
will show you list of the databases;
\q
run the command to backup all the databases:
#pg_dumpall > alldbs.sql
now as the backup completed you have to verify the backup;
# grep "^[\]connect" alldbs.sql
\connect db1
\connect db2
\connect db3...


3: Backup a single table from specific database:
# pg_dump --table contacts -U shahmeer -d firstdb -f conatactstable.sql

How To Restore Postgres Database;

1: Restore postgres database
# psql -U shahmeer firstdb.sql < newdb
if you are going to restore the local database on the remote server then use the below command
#pg_dump firstdb.sql | psql -h hostname dbname

3: Restore All the postgres databases
#su postgres
#psql -f alldb.sql
4: Restore a single postgres table
#psql -f contacts.sql newdb
where new db is the database name and contacts.sql is a dump of table contacts

5:To create a dump of two tables in a single command:
# pg_dump -t table1, -t table2 -U firstdb > 2tables.sql

Thats it, if you have any query regarding this post or if facing any issue please comments here.