# Dolt Dolt is a SQL database with [[Git]]-style versioning baked into the storage engine. Branch, diff, merge, log, and pull requests work on tables instead of files. Created by DoltHub (the company also runs a hosted hub for shared databases), Dolt is wire-compatible with MySQL; existing clients connect without modification, but every commit produces a content-addressable, replayable history. ## What Makes It Different Most databases treat history as an afterthought (audit logs, change-data-capture, temporal tables bolted on). Dolt inverts the model: every state of every table is a content-addressed commit. The query engine reads the working set; everything else (branches, tags, diffs, merges) operates on the commit graph beneath. The result is a database where time travel, blame, and merge are first-class operations rather than tooling glued on top. ## Core Operations (the Git verbs, on tables) - `dolt init` / `dolt clone`: create or copy a versioned database - `dolt branch` / `dolt checkout`: work on parallel timelines of the same data - `dolt diff`: row-level diff between any two commits or branches - `dolt merge`: three-way merge of table contents with conflict resolution - `dolt log` / `dolt blame`: full history of who changed which row, when, and why - `dolt push` / `dolt pull`: sync with remote databases, including DoltHub - `AS OF` SQL: query any past state of any table from a normal SELECT ## Why It Matters Three problems Dolt solves cleanly that most stacks bolt together with duct tape: 1. **Reproducible analytics**: pin a query to a specific commit; the result is deterministic forever 2. **Collaborative datasets**: branch, edit, and PR a shared database the same way teams do code 3. **Auditability**: every row change is signed, dated, and replayable; compliance "for free" This is the durability and observability story that frames it as a foundational layer for systems like [[Gas City]], where every action of every agent must be replayable. ## Trade-offs - **Storage overhead**: keeping every version of every row costs space (mitigated by content-addressed deduplication, but real) - **Write throughput**: not in the same league as a tuned MySQL on point updates; the commit graph adds bookkeeping - **Maturity**: production-ready for moderate workloads, not yet a drop-in replacement for high-throughput OLTP at scale ## Where It Fits - Versioned reference data (mappings, codelists, configuration, ML feature stores) - Public datasets with collaborative editing (DoltHub hosts many) - Audit-critical systems where "who changed what and when" must be replayable - Agent infrastructure (see [[Gas City]]); making every agent action a commit on a queryable timeline ## References - Official site: https://www.dolthub.com/ - GitHub: https://github.com/dolthub/dolt - Documentation: https://docs.dolthub.com/ ## Related - [[Git]] - [[Database]] - [[Database Management Systems (DBMS)]] - [[Relational Databases (RDBMS)]] - [[SQL]] - [[Gas City]]