---
warning: DO NOT CHANGE THIS MANUALLY, THIS IS GENERATED BY https://github.com/duckdb/community-extensions repository, check README there
title: ivf
excerpt: |
  DuckDB Community Extensions
  OSA Levenshtein + Meilisearch-style typo tolerance for FTS (ivf_levenshtein, transposition = 1), with an exact-recall IVF-Flat vector baseline

extension:
  name: ivf
  description: "OSA Levenshtein + Meilisearch-style typo tolerance for FTS (ivf_levenshtein, transposition = 1), with an exact-recall IVF-Flat vector baseline"
  version: 0.1.0
  language: Rust
  build: cargo
  license: MIT
  requires_toolchains: rust
  maintainers:
    - alitrack
  excluded_platforms: "wasm_mvp;wasm_eh;wasm_threads"

repo:
  github: alitrack/duckdb-ivf
  ref: 74b06baaa68c46d7579bcb1ad6b13df3f171ec9b

docs:
  hello_world: |
    LOAD ivf;

    -- Edit distance: OSA Damerau-Levenshtein, a transposition counts as ONE edit
    SELECT ivf_levenshtein('sachin', 'sahcin');   -- 1  (swap h/c)
    SELECT ivf_levenshtein('cruide', 'crude');    -- 1  (deleted char)
    SELECT ivf_levenshtein('abcd', 'dcba', 2);    -- 2  (saturates at maxd)

    -- Exact-recall vector search (IVF-Flat, brute-force baseline / eval ground truth)
    CREATE TABLE items(id BIGINT, vec FLOAT[]);
    INSERT INTO items VALUES (0, [0.0,1.0]), (1, [1.0,0.0]), (2, [0.9,0.1]);
    SELECT * FROM ivf_create_index('items_vec', 'items', 'id', 'vec', 4, 10, true);
    SELECT * FROM ivf_search_exact('items_vec', 'items', 'vec', 2);

  extended_description: |
    ## ivf — OSA Levenshtein + typo tolerance for DuckDB FTS

    Pure-Rust (zero non-std dependencies), C-API v1.2.0. Two capability
    groups:

    **1. `ivf_levenshtein(a, b[, maxd])` — OSA Damerau-Levenshtein.**
    An adjacent transposition counts as ONE edit (the dominant class of real
    keyboard typos; plain Levenshtein counts 2) — the same semantics
    Meilisearch uses for typo tolerance. Banded with early exit, optional
    `maxd` saturation.

    On top of the official `fts` extension (DuckDB >= 2.0) this powers a
    SQL macro layer (`test/fts_typo.sql`, load with `CREATE MACRO` from the
    file) implementing Meilisearch-style search: length-tiered edit budgets
    (<=3 letters never corrected, 4-5 tolerate 1, 6+ tolerate 2), correction
    against the fts `raw_dict` (surface forms), two-way `synonyms` that
    outrank typo correction, and an **expand-not-replace** entry point —
    the original and corrected queries both run and are fused, so a wrong
    correction can never hurt recall. Measured on 120k ag_news headlines
    (bge-m3 vectors, 50 single-typo queries): nDCG@10 0.657 (no correction)
    -> 0.705 (expand) -> 0.909 with vector fusion; word-level correction
    recall 13/50 (the ceiling is the corpus dictionary — names/new words
    are OOV).

    **2. IVF-Flat vector index — exact-recall baseline.**
    `ivf_create_index` / `ivf_search` (nprobe) / `ivf_search_exact`
    (brute force) / `ivf_list`. Positioning: a dependency-free,
    uncompressed exact-recall control for eval harnesses and
    ground-truth checks — not a competitive ANN engine (see official `vss`
    for HNSW, `vindex`/turbovec for quantized ANN).

    **Platforms:** Linux x64, macOS arm64/x64, Windows x64 (CI-built).
    Load with `INSTALL ivf FROM community;` (or `LOAD 'ivf.duckdb_extension'`
    with `-unsigned` for local builds).

extension_star_count: 0
extension_star_count_pretty: 0
extension_download_count: null
extension_download_count_pretty: n/a
image: '/images/community_extensions/social_preview/preview_community_extension_ivf.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 |
|------------------|---------------|-------------|---------|----------|
| ivf_create_index | table         | NULL        | NULL    |          |
| ivf_levenshtein  | scalar        | NULL        | NULL    |          |
| ivf_list         | table         | NULL        | NULL    |          |
| ivf_search       | table         | NULL        | NULL    |          |
| ivf_search_exact | table         | NULL        | NULL    |          |
| ivf_version      | 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 |