> ## Documentation Index
> Fetch the complete documentation index at: https://moridb.sh/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# MariaDB

> MariaDB engine — thin adapter over MySQL with RETURNING support and MariaDB-specific tooling.

## Overview

| Property      | Value                                                        |
| ------------- | ------------------------------------------------------------ |
| Engine ID     | `mariadb`                                                    |
| Wire Protocol | MySQL wire protocol (shared with MySQL)                      |
| Classifier    | AST-based (`vitess/sqlparser`) with MariaDB regex extensions |
| Shadow        | Docker `mariadb:<version>`                                   |

MariaDB is a thin adapter over the MySQL engine. It overrides three methods: `ID()`, `Init()` (passes `mariadb` engine name), and `NewProxy()` (enables `RETURNING` support for MariaDB 10.5+).

**Connection Parameters:** Same as MySQL.

```bash theme={null}
mori init --from "mysql://user:pass@host:3306/mydb"
```

## Differences from MySQL

* **INSERT ... RETURNING** — MariaDB 10.5+ supports `RETURNING` on INSERT/DELETE. The proxy appends `RETURNING pk_col1, pk_col2` to INSERTs sent to shadow, parses the result set for exact PKs, providing PostgreSQL-level delta tracking fidelity.
* **`mariadb-dump`** — Uses `mariadb-dump` instead of `mysqldump` for schema dumps (MySQL's `mysqldump` queries `COLUMN_STATISTICS` which MariaDB doesn't support).
* **`mariadb-admin`** — Uses `mariadb-admin` for container readiness checks (falls back to `mysqladmin`).
* **Container prefix** — Shadow containers use `mori-mariadb-shadow-` prefix instead of `mori-mysql-shadow-`.
* **No `only_full_group_by` issue** — MariaDB does not enable this SQL mode by default, avoiding the aggregate re-aggregation conflict that affects MySQL.
* **MariaDB-specific classification** — Regex patterns added for `INSERT/DELETE/REPLACE ... RETURNING`, `EXECUTE IMMEDIATE`, and `CREATE/DROP SEQUENCE`.

## Differences from PostgreSQL

Inherits all MySQL differences from PostgreSQL (no `ctid`, no cursors, no LISTEN/UNLISTEN, auto-increment offsets, etc.). See the [MySQL engine page](/docs/engines/mysql) for the full list.

## Known Limitations

* Inherits all MySQL limitations
* Vitess parser is hardcoded to MySQL 8.0.30 — MariaDB-specific syntax falls through to regex fallback which may be a little less accurate.