Tendermint DB

Common database interface for various database backends. Primarily meant for applications built on Tendermint, such as the Cosmos SDK, but can be used independently of these as well.

Minimum Go Version

Go 1.13+

Supported Database Backends

• GoLevelDB [stable]: A pure Go implementation of LevelDB (see below). Currently the default on-disk database used in the Cosmos SDK.

• MemDB [stable]: An in-memory database using Google's B-tree package. Has very high performance both for reads, writes, and range scans, but is not durable and will lose all data on process exit. Does not support transactions. Suitable for e.g. caches, working sets, and tests. Used for IAVL working sets when the pruning strategy allows it.

• LevelDB [experimental]: A Go wrapper around LevelDB. Uses LSM-trees for on-disk storage, which have good performance for write-heavy workloads, particularly on spinning disks, but requires periodic compaction to maintain decent read performance and reclaim disk space. Does not support transactions.

• BoltDB [experimental]: A fork of BoltDB. Uses B+trees for on-disk storage, which have good performance for read-heavy workloads and range scans. Supports serializable ACID transactions.

• RocksDB [experimental]: A Go wrapper around RocksDB. Similarly to LevelDB (above) it uses LSM-trees for on-disk storage, but is optimized for fast storage media such as SSDs and memory. Supports atomic transactions, but not full ACID transactions.

Meta-databases

• PrefixDB [stable]: A database which wraps another database and uses a static prefix for all keys. This allows multiple logical databases to be stored in a common underlying databases by using different namespaces. Used by the Cosmos SDK to give different modules their own namespaced database in a single application database.

• RemoteDB [experimental]: A database that connects to distributed Tendermint db instances via gRPC. This can help with detaching difficult deployments such as LevelDB, and can also ease dependency management for Tendermint developers.

Tests

To test common databases, run make test. If all databases are available on the local machine, use make test-all to test them all.