Added SQLite backups blog article

content/blog/miscellaneous/sqlite-backups.md

@@ -0,0 +1,34 @@
+---
+title: How to properly backup your SQLite databases
+description: I used to simply .dump those
+date: 2021-11-09
+tags:
+- backups
+- SQLite
+---
+
+## Introduction
+
+SQLite is great and I have been using it for years while self-hosting various services. It is easier, lighter and fast enough for most needs which is critical when the time you can spend managing your personal infrastructure is finite.
+
+Recently while talking with a developer friend I learned about the `user_version` PRAGMA, which could be a simple way to handle migrations in a custom app. For migrations to work you need a way to save the current revision of your schema somewhere : I was using a table for that, with a single column and a single row to store that revision. This PRAGMA would be a nice way to handle this in SQLite.
+
+## The backup problem
+
+The problem with this PRAGMA is that it does not appear in a `.dump`! So if you rely on this to backup your databases (like I did) then you would lose the schema revision upon restoring your service, or migrating it to another host.
+
+When looking into this problem I learned that a better way to handle SQLite backups is with `VACUUM INTO 'file.db';` (added in SQLite 3.27 in early 2019). Not only does this create a perfect copy of your database at the point in time you run this command, the PRAGMA are kept and the indexes will not need to be rebuilt!
+
+## Conclusion
+
+I switched all my SQLite backups to `VACUUM INTO` and will not look back!
+
+If by chance you are using my [borg ansible role]({{< ref "docs/adyxax.org/backups/borg-ansible-role.md" >}}) to manage your backups, here is what an SQLite job entry looks like :
+```
+- name: srv-short-db
+  path: "/tmp/short.db"
+  pre_command: "echo 'VACUUM INTO \"/tmp/short.db\"'|sqlite3 /srv/short-data/short.db"
+  post_command: "rm -f /tmp/short.db"
+```
+
+I did not yet migrate away from my schema version table to replace it with the pragma : I need to think about it more before committing to this kind of change.