Postgresql – psql empty database before restore

postgresqlpsql

I want to restore a database of postgreSQL, but before do it i need to empty the restore target database.

Is there an option of psql to do it ?

Now i use a command line as the following :

psql -U postgres db_test < testdb.sql

Best Answer

There are two options here - if your backup is plain text then you add the -c option to pg_dump - ie

pg_dump -c mydb > mydb.sql

Otherwise if your using -Fc or -Ft on pg_dump then you use the -c flag on pg_restore

pg_dump -Ft -b mydb > db.tar

pg_restore -c -d newdb db.tar

Related Solutions

Linux – Running psql in Linux Command Line

The directory /usr/local/pgsql/bin is not in your PATH (and neither is . - which is a good thing for security reasons). Simply run it like this if you're in that directory:

./psql test

which says run psql from the current directory (./).

Ubuntu – Multiple instances of Postgres after Ubuntu upgrade

Ubuntu being a Debian-based system has the ability to run multiple instances of Postgres as you are seeing. Generally unless configured otherwise the first instance started will have the default Postgres port and each subsequent instance will take the next higher port if it is available. These ports can be defined in the config files under /etc/postgresql/<version>/<cluster>/ so that they don't change should you need to but I'd actually need to. In fact a cursory look at the /etc/init.d/postgresql would also show you that you can set environment variables through /etc/postgresql/<version>/<cluster>/environment.

The package managers were even nice enough to include /usr/share/doc/postgresql-common/README.Debian.gz which has a section that quickly explains how the cluster management is handled including the pg_lsclusters command which will give you the Postgres version and port number along with other nice details about each configured cluster.

To answer question in comment regarding stopping an instance... You can edit the start.conf file under /etc/postgresql/<version>/<cluster>/ and change it from auto to disabled or manual. To quote the default start.conf file itself...

# Automatic startup configuration
# auto: automatically start/stop the cluster in the init script
# manual: do not start/stop in init scripts, but allow manual startup with
#         pg_ctlcluster
# disabled: do not allow manual startup with pg_ctlcluster (this can be easily
#           circumvented and is only meant to be a small protection for
#           accidents).

Best Answer

Related Solutions

Linux – Running psql in Linux Command Line

Ubuntu – Multiple instances of Postgres after Ubuntu upgrade

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