---
warning: DO NOT CHANGE THIS MANUALLY, THIS IS GENERATED BY https://github.com/duckdb/community-extensions repository, check README there
title: duckomo
excerpt: |
  DuckDB Community Extensions
  Query Open-Meteo OM arrays with selective reads and geographic coordinates

extension:
  name: duckomo
  description: Query Open-Meteo OM arrays with selective reads and geographic coordinates
  version: 0.3.5-rc.1
  language: C++
  build: cmake
  license: Apache-2.0
  maintainers:
    - blizhan
  # Linux glibc and macOS, x86_64 and ARM64, have verified release artifacts.
  excluded_platforms: "linux_amd64_musl;linux_arm64_musl;windows_amd64;windows_arm64;windows_amd64_mingw;windows_amd64_rtools;wasm_mvp;wasm_eh;wasm_threads"

repo:
  github: chorust/duckomo
  ref: 55d66f3fbd3199d7471b8cd569c43cc91a8cec7e

docs:
  hello_world: |
    LOAD duckomo;
    SELECT DISTINCT function_name
    FROM duckdb_functions()
    WHERE function_name IN ('read_om', 'read_om_raw', 'read_om_regions', 'om_grid_info')
    ORDER BY function_name;
  extended_description: |
    DuckOMO reads Float32 arrays in Open-Meteo OM v3 files as SQL tables.
    It supports selective value reads, geographic coordinates, explicitly
    declared semantic axes, polygon regions, and nearest-point sampling.
    Local files need no HTTPFS dependency. HTTP(S) and S3 reads use DuckDB's
    official httpfs extension: INSTALL httpfs; LOAD httpfs;

    DuckDB 2.0.0 compatibility and release artifacts have been verified on
    Linux glibc x86_64/ARM64 and macOS Intel/Apple Silicon. Separate source
    compatibility checks also cover DuckDB 1.5.4, 1.5.5, and 1.5.6.

    This source version is a prerelease. Async remote I/O remains experimental
    and has not shown a consistent speedup. Experimental cross-batch prefetch
    is disabled by default; some first local queries exceed the project's
    performance target. Grid validation is limited to the documented objects
    and domains; it does not establish support for every OM file or grid.
    See https://github.com/chorust/duckomo for supported inputs and examples.

extension_star_count: 1
extension_star_count_pretty: 1
extension_download_count: 1
extension_download_count_pretty: 1
image: '/images/community_extensions/social_preview/preview_community_extension_duckomo.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 |
|---------------------------|---------------|-------------|---------|----------|
| duckomo_last_scan_metrics | table         | NULL        | NULL    |          |
| om_grid_info              | table         | NULL        | NULL    |          |
| read_om                   | table         | NULL        | NULL    |          |
| read_om_raw               | table         | NULL        | NULL    |          |
| read_om_regions           | table         | 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 |
|--------------------------------|-----------------------------------------------------------------------------------------|------------|--------|---------|-------------|
| duckomo_async_io               | Read merged remote OM ranges concurrently (DuckDB 2.0 only)                             | BOOLEAN    | GLOBAL | []      | true        |
| duckomo_async_max_inflight     | Maximum concurrent remote OM reads per worker                                           | UBIGINT    | GLOBAL | []      | 8           |
| duckomo_async_prefetch_batches | Experimental remote full-scan prefetch window (1 disables cross-batch reads)            | UBIGINT    | GLOBAL | []      | 1           |
| duckomo_max_threads            | Maximum workers used by read_om (0 uses DuckDB's thread limit)                          | BIGINT     | GLOBAL | []      | 0           |
| duckomo_remote_max_request     | Maximum bytes of one merged remote OM read                                              | UBIGINT    | GLOBAL | []      | 65536       |
| duckomo_remote_merge           | Merge nearby remote OM reads (local files ignore this)                                  | BOOLEAN    | GLOBAL | []      | true        |
| duckomo_remote_merge_gap       | Maximum gap in bytes merged into one remote OM read                                     | UBIGINT    | GLOBAL | []      | 4096        |
| duckomo_revalidate_metadata    | Re-read every OM variable before scanning (slower; detects metadata changes after bind) | BOOLEAN    | GLOBAL | []      | false       |
| temp_directory                 | Set the directory to which temporary files are written.                                 | VARCHAR    | GLOBAL | []      | post.db.tmp |