Databases

MySQL/MariaDB, PostgreSQL and MongoDB side by side. Each has its own admin tool, and backups are offered before anything destructive.

Engines

The Database page has a tab for each engine. Each one installs, starts and stops independently, and an engine you stop stays stopped until you start it. The stack and autostart won't bring it back.

Engine	Default	Admin tool	CLI
MySQL / MariaDB	8.4 LTS on 127.0.0.1:3306, user root, no password	phpMyAdmin at https://phpmyadmin.test (HeidiSQL also available on Windows)	mullion mysql, db, mariadb
PostgreSQL	17 on 127.0.0.1:5432, user postgres	pgAdmin 4, with a "Mullion (PostgreSQL)" server already registered	mullion postgres (pg), pgadmin
MongoDB	8.0 on 127.0.0.1:27017	mongo-express at https://mongo.test	mullion mongo, mongo-express

Installed admin tools appear as buttons in the panel's top bar and can be uninstalled from their engine's tab. Uninstalling an admin tool leaves the database server alone.

MySQL and MariaDB

$ mullion mysql install          # newest 8.4 LTS
$ mullion mysql install 8.0      # a branch, "latest", or a full version
$ mullion mariadb                # switch to MariaDB (newest stable)
$ mullion mysql password secret  # phpMyAdmin follows automatically
$ mullion db create shop         # utf8mb4
$ mullion db list
$ mullion mysql restore ~/Mullion-Backups/2026-09-23_092011-mysql

When you switch versions, your databases migrate automatically: Mullion dumps them from the old server, starts the new one with a fresh data folder, and restores the dump. The old data folder and the dump are kept as backups. If it replaces another MySQL (Laragon, XAMPP, a Homebrew service), it always offers a backup first and imports it.

PostgreSQL

$ mullion postgres install       # newest 17; "16", "latest" or "16.4" also work
$ mullion pg db create analytics
$ mullion pg password secret
$ mullion pgadmin                # installs (first time) and opens pgAdmin 4

Switching to a different major version stops the previous server. Data folders are per major version, so the old data stays on disk untouched, and Mullion prints where it is.

MongoDB

$ mullion mongo install          # newest 8.0; "7.0", "latest" or a full version
$ mullion mongo db create events
$ mullion mongo-express          # admin UI at https://mongo.test

Backups

• Back up now on an engine's tab writes a timestamped folder, such as 2026-09-24_181502-postgres. You can also run mullion mysql backup, mullion postgres backup, or mullion mongo backup.
• Each engine's Backups card lists its backups with their size and contents, and has Restore and Delete buttons.
• mullion backups lists every backup from the CLI.
• Backups go to a folder next to the install folder by default: ~/.mullion-Backups or C:\Mullion-Backups. That way they survive an uninstall. Change the folder in Settings.

$ mullion postgres restore <backup-folder>            # every database, plus roles (best effort)
$ mullion postgres restore <backup-folder> shop       # just one database
$ mullion mongo restore <backup-folder-or-.archive.gz>
$ mullion mysql restore <file.sql-or-folder>

Note: Backups are also taken automatically when you switch MySQL versions and, if you choose, before uninstalling an engine.

Uninstalling an engine

An engine's Uninstall… button, or mullion <engine> uninstall, stops the server, backs it up, and removes the binaries, the data and its admin tool. The PostgreSQL and MongoDB commands take --keep-data, --no-backup and --yes.

Changing ports

If another program already uses a database's port, move the engine. Mullion checks the new port for conflicts and restarts the engine if it's running.

$ mullion port set postgres 5433
$ mullion port set mysql 3307 --force   # even if something holds it

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