Database backends

Minetest supports several database backends. This page provides a comparison of all 4 (actually 5, but the dummy backend generally isn't useful) backends.

The database backend is set using the backend setting in world.mt.

If you want to migrate a world to a new backend, use minetestserver --migrate <name of new backend> --world <path to your world directory>.

Comparison table

Backend	Speed	Reliability	Compatibility with builds
SQLite3	Good	Acceptable (problems can arise with concurrent accesses)	Very good (always supported)
LevelDB	Good	Good	Mostly supported
Redis	Very good (data kept in RAM)	Good	Inconvenient (redis server required)
PostgreSQL	Very good (most used data are in memory, other are fetched from disk)	Very good	Inconvenient (PostgreSQL server required)
Dummy	Blazing fast	N/A (nothing is saved to disk)	N/A (nothing is saved to disk)

The Compatibility with builds column is only relevant if you want to distribute the worlds.

SQLite3

SQLite3 is the default backend for all Minetest worlds, it is supported by every Minetest build and is therefore the standard database format that is used to distribute worlds.

LevelDB

LevelDB is mostly used on servers because of its improved reliability and possibly speed. You need to install it additionally.

Redis

Redis support was added to Minetest in April 2014, redis is mainly useful for servers as it allows multiple worlds to be stored in one redis instance. You need to install it additionally (libhiredis library).

Information about setting up a redis server can be found here: http://redis.io/topics/quickstart

world.mt settings for Redis

redis_address -- The IP or hostname of the redis server.

redis_port -- The port of the redis server. Optional, default: 6379

redis_hash -- Hash where the MapBlocks are stored in, if you want multiple worlds in one redis instance this needs to be different for each world. If you don't need that you can use e.g. IGNORED.

PostgreSQL

PostgreSQL support was added to Minetest in May 2016, it's mainly useful for servers as it allows multiple worlds in a single instance, in multiple databases.

PostgreSQL is an excellent alternate to Redis. It doesn't store all data in memory, only recent and frequent data are in memory. All data is on disk storage and data storage is very robust. You can also interface easily a website in front of your database to offer a frontend to your users.

Whereas we support older versions, it's recommended to use PostgreSQL 9.5 at least.

world.mt for PostgreSQL

pgsql_connection -- PostgreSQL connection string | host=<db_host> user=<db_user> password=<db_password> dbname=<db_name>

Dummy

A dummy database backend, which stores all MapBlocks in RAM without saving them and will most likely not be of any use for you.