---
warning: DO NOT CHANGE THIS MANUALLY, THIS IS GENERATED BY https://github.com/duckdb/community-extensions repository, check README there
title: duckdb_rphonetic
excerpt: |
  DuckDB Community Extensions
  Phonetic algorithms for German and European name matching

extension:
  name: duckdb_rphonetic
  description: Phonetic algorithms for German and European name matching
  version: 0.2.0
  language: Rust
  build: cmake
  license: Apache-2.0
  requires_toolchains: "rust;python3"
  excluded_platforms: "linux_amd64_musl"
  maintainers:
    - guizmaii

repo:
  github: guizmaii-opensource/duckdb_rphonetic
  # v0.2.0
  ref: ac89f6debd3f5339df18553fc504b682f05d1185

docs:
  hello_world: |
    -- Kölner Phonetik: a German-language counterpart to Soundex.
    -- Spelling variants of the same name encode identically.
    SELECT cologne_phonetic('Müller'), cologne_phonetic('Mueller');
    -- 657, 657

    -- Daitch-Mokotoff Soundex returns SEVERAL codes for ambiguous spellings,
    -- so a match is a set overlap rather than an equality test.
    SELECT daitch_mokotoff('Klein'), daitch_mokotoff('Cleyn');
    -- [586000], [586000, 486000]

    SELECT list_has_any(daitch_mokotoff('Klein'), daitch_mokotoff('Cleyn'));
    -- true
  extended_description: |
    Two phonetic encoders aimed at European name matching, wrapping the
    [rphonetic](https://crates.io/crates/rphonetic) crate by Dalvany — a Rust
    port of Apache Commons Codec.

    * `cologne_phonetic(VARCHAR) -> VARCHAR` — Kölner Phonetik (Postel, 1969),
      the German-language counterpart to Soundex. Handles umlauts and ß, so
      `Müller` and `Mueller` share a code.
    * `daitch_mokotoff(VARCHAR) -> VARCHAR[]` — Daitch-Mokotoff Soundex, built
      for Germanic and Slavic surnames. Returns a list because ambiguous
      spellings legitimately encode several ways; match with `list_has_any`.

    Neither exists in core DuckDB, whose `soundex` and `double_metaphone` are
    tuned for English. Trigram similarity is not a substitute: `Klein` and
    `Cleyn` share no trigrams at all, yet both encoders match them.

    **Behavioural note.** Kölner Phonetik implementations disagree on whether a
    dropped `0` breaks a run of identical digits. This extension follows
    `rphonetic`, which yields `cologne_phonetic('Dieter') = '227'`; Apache
    Commons Codec yields `27`. The two differ on 36 of a 279-name test corpus.
    Every divergence is committed to the repository and pinned by a test, so the
    output cannot change silently. An `H` carries no code at all and, since
    0.2.0, never breaks a run: `cologne_phonetic('Mülhler') = '657'`, the same
    as `Müller`, on which both implementations agree. The published reference vectors
    (`Müller-Lüdenscheidt` -> `65752682`, `Wikipedia` -> `3412`,
    `Breschnew` -> `17863`) are unaffected. Daitch-Mokotoff agrees with
    Commons Codec on all 279 names.

extension_star_count: 1
extension_star_count_pretty: 1
extension_download_count: 1443
extension_download_count_pretty: 1.4k
image: '/images/community_extensions/social_preview/preview_community_extension_duckdb_rphonetic.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 |
|------------------|---------------|-------------|---------|----------|
| cologne_phonetic | scalar        | NULL        | NULL    |          |
| daitch_mokotoff  | 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>

This extension does not add any settings.