---
warning: DO NOT CHANGE THIS MANUALLY, THIS IS GENERATED BY https://github.com/duckdb/community-extensions repository, check README there
title: dp
excerpt: |
  DuckDB Community Extensions
  Differential-privacy publishing in SQL — dp_count/dp_sum/dp_mean with the classic Laplace mechanism (pure SQL macros, deterministic reproducible noise)

extension:
  name: dp
  description: Differential-privacy publishing in SQL — dp_count/dp_sum/dp_mean with the classic Laplace mechanism (pure SQL macros, deterministic reproducible noise)
  version: 0.1.0
  language: Rust
  build: cargo
  license: MIT
  excluded_platforms: "wasm_mvp;wasm_eh;wasm_threads;windows_amd64_rtools;windows_amd64_mingw;linux_amd64_musl;linux_arm64_musl;windows_arm64"
  requires_toolchains: "rust"
  test_config: '{"test_env_variables": {"SKIP_TESTS": "1"}}'
  maintainers:
    - alitrack

repo:
  github: alitrack/duckdb-dp
  ref: 5ec9b7a679ed916268ee5873df43cbc6b1039891

docs:
  hello_world: |
    -- (epsilon, 0)-differential-privacy publishing, straight in SQL.
    -- The Rust extension is a thin shim: on LOAD it registers the dp_*
    -- macros from a pure-SQL script. Zero per-row native work.

    CREATE TABLE patients AS
      SELECT range AS id,
             20 + (hash('age' || range) % 60) AS age
      FROM range(300);

    -- Clip + Laplace(1/eps) count, deterministic per salt (reproducible)
    D SELECT dp_count(array_agg(age), 0.1, 'pub_2026q4') AS dp_n FROM patients;
    ┌─────────────┐
    │    dp_n     │
    │   double    │
    ├─────────────┤
    │ 307.23651554674376 │
    └─────────────┘

    -- Clipped mean: eps = privacy budget, lb/ub = clipping bounds
    D SELECT dp_mean(array_agg(age), 0.1, 0, 100, 'pub_2026q4') AS dp_age FROM patients;
    D SELECT dp_sum(array_agg(age), 0.01, 0, 100, 'pub_2026q4') AS dp_sum_tighter FROM patients;

  extended_description: |
    # duckdb-dp — differential privacy for DuckDB

    Publish (epsilon, 0)-differentially-private aggregate statistics directly in
    SQL. The mechanism is the classic **Laplace** mechanism; all the privacy math
    is **pure SQL macros** (no per-row native code). The bundled Rust extension
    is a thin shim that exists only so the community registry can build a
    loadable binary: on `LOAD` it executes the SQL script and registers the
    `dp_*` macros.

    ## Functions

    | function | mechanism | sensitivity |
    |---|---|---|
    | `dp_count(x, eps, salt)` | count + Laplace(1/eps) | 1 |
    | `dp_sum(x, eps, lb, ub, salt)` | clipped sum + Laplace((ub-lb)/eps) | ub-lb |
    | `dp_mean(x, eps, lb, ub, salt)` | clipped mean + Laplace((ub-lb)/(2n·eps)) | (ub-lb)/(2n) |
    | `dp_noise_lap(b, salt)` / `dp_noise_gauss(sigma, salt)` | noise primitives | — |
    | `dp_u(salt)` / `dp_v(salt)` | deterministic uniform (internal) | — |

    Aggregates take a **LIST** (house convention, same as `duckdb_stats`):

    ```sql
    SELECT dp_count(array_agg(age), 0.1, 'pub_2026q4') FROM t;
    ```

    - **eps** = privacy budget; `eps <= 0` returns NULL (nothing published).
    - **salt** = publication identifier. Same salt → same noise on re-run
      (reproducible dashboards); different salt → independent noise (assign a
      fresh salt per publication when budget is tracked per release). The salt
      must be a single constant shared by all rows.
    - **lb / ub** = clipping bounds — semantically core, not optional: the
      noise scale is `(ub - lb)`, so no clip means no sensitivity guarantee.
    - NULL rows are not counted (matches COUNT/AVG); `ub <= lb` → NULL.

    ## Honest scope (prototype)

    1. **Single-query mechanism, no composition accounting.** Publishing several
       `dp_*` values back-to-back — you sum the budgets yourself (basic
       composition, Σeps) or use advanced composition (Dwork-Roth Thm 3.7).
    2. **Non-adaptive.** Noise derived from one salt is correlated across calls;
       reusing a salt across independent publications shares noise and breaks
       additivity.
    3. **Numerics.** 48-bit deterministic uniform; the log domain is clamped to
       `[2^-20, 1-2^-20]` (a 48-bit value within 2^-48 of 1 would otherwise
       round `1-V` to 0 → `ln(0)` → ±inf; regression-locked by the test suite).
    4. **Upgrade path.** For RDP / ledger accounting / complex queries, move to
       a C++ extension over **OpenDP** (MIT / Rust / C ABI).

    ## Verification

    - `bash run_tests.sh` — 12 assertions (determinism, salt divergence, eps
      bounds, empty, NULL semantics, clipping, numeric, grouped, ub<=lb, mean
      scale, tail-finite), all green → exit 0.
    - `python3 verify_dp.py` — moment checks vs theory (Laplace σ≈b·√2,
      Gaussian σ, uniform, no collisions), N=2000, ±10%.
    - End-to-end: the compiled binary `LOAD`s in the DuckDB CLI and produces
      values **bit-identical** to the raw `dp.sql`, deterministic across loads.

    ## Relation to the registry

    Registry 370-extension rescan (2026-10-18): no differential-privacy
    coverage. (`differential` = database versioning / time travel; `table_guard`
    = table-level access control; `semantic_profile` = PII detection only —
    none of them implement a DP mechanism.) `duckdb_stats` is the statistics
    layer (inference / hypothesis tests); this is the publishing layer
    (privacy budget) — no overlap.

extension_star_count: 0
extension_star_count_pretty: 0
extension_download_count: 529
extension_download_count_pretty: 529
image: '/images/community_extensions/social_preview/preview_community_extension_dp.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 |
|----------------|---------------|-------------|---------|----------|
| dp_clip        | macro         | NULL        | NULL    |          |
| dp_count       | macro         | NULL        | NULL    |          |
| dp_mean        | macro         | NULL        | NULL    |          |
| dp_noise_gauss | macro         | NULL        | NULL    |          |
| dp_noise_lap   | macro         | NULL        | NULL    |          |
| dp_non_null    | macro         | NULL        | NULL    |          |
| dp_sum         | macro         | NULL        | NULL    |          |
| dp_u           | macro         | NULL        | NULL    |          |
| dp_v           | macro         | 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 |