History[03][04]

In 2011, Howard Chu introduced MDB, a memory-mapped database backend for OpenLDAP, later renamed to [LMDB] (https://symas.com/lmdb/technical/)(Lightning Memory-Mapped Database). In 2013, BoltDB was initially started by Ben Johnson as a port of LMDB to Go, but then the two projects diverged as the author of Bolt decided to focus on simplicity and providing the easy-to-use Go API. The goal of BoltDB became to provide a simple, fast, and reliable database for projects that don't require a full database server such as Postgres or MySQL. With BoltDB being stable, its API fixed, and its file format fixed, the author considered the project a success. Leaving it in such a state, the project was abandoned by its author in 2017.

Checkpoints

Concurrency Control

BoltDB allows only one read-write transaction at a time.

Data Model[04]

Bolt is a key-value store that provides an ordered map, which allows easy access and lookup.

Foreign Keys

Indexes

Isolation Levels

Joins

Logging[04]

Bolt saves data into a single memory-mapped file on disk. It doesn’t have a separate journal or write-ahead log.

Query Compilation

Query Interface

Storage Model

Storage Organization

System Architecture

Views[04]

Bolt allows only one read-write transaction at a time but allows as many read-only transactions as you want at a time. Each transaction has a consistent view of the data as it existed when the transaction started. BoltDB recommends three types of transactions: read-write transactions with DB.Update, read-only transactions with DB.View and batch read-write transactions with DB.Batch. Along with the three recommended transactions, BoltDB also allows manual transaction management with DB.Begin.