Add Dump All Databases To A SQL File as a postgres til

README.md

@@ -10,7 +10,7 @@ pairing with smart people at Hashrocket.
 
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@@ -532,6 +532,7 @@ _1066 TILs and counting..._
 - [Determine Types Of JSONB Records](postgres/determine-types-of-jsonb-records.md)
 - [Determining The Age Of Things](postgres/determining-the-age-of-things.md)
 - [Difference Between Explain And Explain Analyze](postgres/difference-between-explain-and-explain-analyze.md)
+- [Dump All Databases To A SQL File](postgres/dump-all-databases-to-a-sql-file.md)
 - [Dump And Restore A Database](postgres/dump-and-restore-a-database.md)
 - [Duplicate A Local Database](postgres/duplicate-a-local-database.md)
 - [Edit Existing Functions](postgres/edit-existing-functions.md)

postgres/dump-all-databases-to-a-sql-file.md

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+# 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.
+
+```bash
+$ 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.
+
+```bash
+$ pg_dumpall \
+  --exclude-database="template*" \
+  > postgres_13_1_cluster_dump.sql
+```
+
+This data dump can be restored with the new install using:
+
+```bash
+$ psql -f postgres_13_1_cluster_dump.sql postgres
+```
+
+I wrote more about this process in [Reinstall Postgres with OpenSSL Using
+asdf](https://dev.to/jbranchaud/reinstall-postgresql-with-openssl-using-asdf-cmj).
+
+Also, see `pg_dumpall --help` or the [Postgres
+docs](https://www.postgresql.org/docs/current/app-pg-dumpall.html) for more
+details.