Database backends

Minetest supports several database backends. This page provides a comparison of all 3 (actually 4, 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	Acceptable	Acceptable (db can corrupt if accessed while open)	Very good (supported by any Minetest version)
LevelDB	Good	Good	Mostly supported
Redis	Very good (most data is always kept in RAM)	Good	Bad (needs a running Redis server)
Dummy	Very good (all data is always kept in RAM)	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 the ability to use more than 4 GB of space. Installing apart.

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.

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.

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.