Dump All Databases To A SQL File

I recently needed to reinstall my local Postgres installation. I had several databases with data in that cluster that I wanted to preserve. Before I could go uninstalling and re-installing Postgres, I needed to dump the entire cluster of databases.

The pg_dumpall command that installs with Postgres can be used for this.

$ pg_dumpall > postgres_13_1_cluster_dump.sql

The command outputs to stdout a SQL dump of all the databases stored in the data directory of this Postgres instance.

I took this a step further and ignored the template0 and template1 directories because I knew those would come with the new install. I did that by adding the --exclude-database flag with a pattern.

$ pg_dumpall \
  --exclude-database="template*" \
  > postgres_13_1_cluster_dump.sql

This data dump can be restored with the new install using:

$ psql -f postgres_13_1_cluster_dump.sql postgres

I wrote more about this process in Reinstall Postgres with OpenSSL Using asdf.

Also, see pg_dumpall --help or the Postgres docs for more details.