---
warning: DO NOT CHANGE THIS MANUALLY, THIS IS GENERATED BY https://github.com/duckdb/community-extensions repository, check README there
title: mentat
excerpt: |
  DuckDB Community Extensions
  Datomic-compatible Datalog query engine as a DuckDB extension

extension:
  name: mentat
  description: Datomic-compatible Datalog query engine as a DuckDB extension
  version: 1.19.1
  language: Rust
  build: cargo
  license: Apache-2.0
  maintainers:
    - gburd
  requires_toolchains: "rust;python3"
  excluded_platforms: "wasm_mvp;wasm_eh;wasm_threads;windows_amd64_mingw;linux_amd64_musl"
repo:
  github: gburd/mentat
  ref: c9ebe020f8ff5feb71c7792fc56669101b367868
  variegata: c9ebe020f8ff5feb71c7792fc56669101b367868
docs:
  hello_world: |
    LOAD mentat;
    -- Transact a schema and data into the mentat store 'default'. Its datoms are
    -- DuckDB tables (schema `mentat`) in the database you have open.
    SELECT edn_t('default',
      '[{:db/ident :person/name :db/valueType :db.type/string :db/cardinality :db.cardinality/one}]');
    SELECT edn_t('default', '[{:person/name "Alice"} {:person/name "Bob"}]');
    -- Datalog: a table function, so the rows join against your own tables.
    SELECT * FROM edn_q('default',
      '[:find ?e ?name :where [?e :person/name ?name]]', '{}');
    SELECT * FROM edn_q('default',
      '[:find ?e . :in ?name :where [?e :person/name ?name]]', '{"inputs": ["Alice"]}');
    -- The datoms are plain DuckDB rows.
    SELECT count(*) FROM mentat.datoms;
  extended_description: |
    mentat is a Datomic-compatible database: an EDN/Datalog front-end over an
    entity-attribute-value store with history. This extension stores mentat's
    datoms in DuckDB: each mentat store is a schema of ordinary tables in the
    database the extension is loaded into, so the data persists with that
    database and plain SQL can read it. It exposes `edn_t` (transact), `edn_q`
    (Datalog query table function, with :in inputs and asOf/since), `edn_pull`
    (pull pattern -> JSON) and `edn_eval` (sandboxed mino script), so Datalog
    query results can be joined against native DuckDB tables. The same engine is also
    available as an embedded Rust library and CLI (on SQLite) and a PostgreSQL
    extension (`pg_mentat`). Source: https://codeberg.org/gregburd/mentat

extension_star_count: 2
extension_star_count_pretty: 2
extension_download_count: 679
extension_download_count_pretty: 679
image: '/images/community_extensions/social_preview/preview_community_extension_mentat.png'
layout: community_extension_doc
---
### Compatibility Matrix

This table covers all DuckDB releases that have not reached [end-of-life](https://duckdb.org/release_calendar), including LTS releases, and shows the 2 most recent patch releases of each. Older patch releases are not listed, but the extension may be available for them as well.

<div class="extension_compatibility_table"></div>

| Platform | 1.4.4 | 1.4.5 | 1.5.5 | 1.5.6 | 2.0.0 |
| :--- | :---: | :---: | :---: | :---: | :---: |
| Linux AMD64 | ❌ | ❌ | ❌ | ✅ | ✅ |
| Linux ARM64 | ❌ | ❌ | ❌ | ✅ | ✅ |
| macOS AMD64 | ❌ | ❌ | ❌ | ✅ | ✅ |
| macOS ARM64 | ❌ | ❌ | ❌ | ✅ | ✅ |
| Windows AMD64 | ❌ | ❌ | ❌ | ✅ | ✅ |
| Windows ARM64 | ❌ | ❌ | ❌ | ❌ | ❌ |
| WebAssembly | ❌ | ❌ | ❌ | ❌ | ❌ |

### Installing and Loading
```sql
INSTALL {{ page.extension.name }} FROM community;
LOAD {{ page.extension.name }};
```

{% if page.docs.hello_world %}
### Example
```sql
{{ page.docs.hello_world }}```
{% endif %}

{% if page.docs.extended_description %}
### About {{ page.extension.name }}
{{ page.docs.extended_description }}
{% endif %}
### Added Functions

<div class="extension_functions_table"></div>

| function_name | function_type | description | comment | examples |
|---------------|---------------|-------------|---------|----------|
| edn_eval      | scalar        | NULL        | NULL    |          |
| edn_pull      | scalar        | NULL        | NULL    |          |
| edn_q         | table         | NULL        | NULL    |          |
| edn_t         | scalar        | NULL        | NULL    |          |
| mentat_import | scalar        | NULL        | NULL    |          |

### Overloaded Functions

<div class="extension_functions_table"></div>

This extension does not add any function overloads.

### Added Types

<div class="extension_types_table"></div>

This extension does not add any types.

### Added Settings

<div class="extension_settings_table"></div>

|      name      |                       description                       | input_type | scope  | aliases | typed_value |
|----------------|---------------------------------------------------------|------------|--------|---------|-------------|
| temp_directory | Set the directory to which temporary files are written. | VARCHAR    | GLOBAL | []      | post.db.tmp |