MobilityDuck

MEOS (Mobility Engine, Open Source) is a C library that enables the manipulation of temporal and spatiotemporal data based on MobilityDB's data types and functions.

MobilityDuck is a binding for DuckDB built on top of MEOS.

The MobilityDB project is developed by the Computer & Decision Engineering Department of the Université libre de Bruxelles (ULB) under the direction of Prof. Esteban Zimányi. ULB is an OGC Associate Member and member of the OGC Moving Feature Standard Working Group (MF-SWG).

This repository is based on https://github.com/duckdb/extension-template.

With MobilityDuck, users can use these data types and functions directly in DuckDB queries.

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1. Requirements

MobilityDuck needs some dependencies(including MEOS) which can be installed through VCPKG. Run the following to enable it:

cd <your-working-dir-not-the-plugin-repo>
git clone https://github.com/Microsoft/vcpkg.git
sh ./vcpkg/scripts/bootstrap.sh -disableMetrics
export VCPKG_TOOLCHAIN_PATH=`pwd`/vcpkg/scripts/buildsystems/vcpkg.cmake

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2. Building MobilityDuck

Clone the repository

git clone --recurse-submodules https://github.com/MobilityDB/MobilityDuck.git

Note that --recurse-submodules will ensure DuckDB is pulled which is required to build the extension.

Build steps

To build the extension, from the root directory (mobilityduck), run:

make

Or use ninja for faster build (subsequent builds after the first build) relying on cache:

GEN=ninja make

The main binaries that will be built are:

./build/release/duckdb
./build/release/test/unittest
./build/release/extension/mobilityduck/mobilityduck.duckdb_extension

• duckdb is the binary for the duckdb shell with the extension code automatically loaded.
• unittest is the test runner of duckdb. Again, the extension is already linked into the binary.
• mobilityduck.duckdb_extension is the loadable binary as it would be distributed.

3. Running the extension

To run the extension code, start the shell with ./build/release/duckdb.

Now we can use the features from the extension directly in DuckDB. Some examples:

D SELECT '100@2025-01-01 10:00:00+05'::TINT as tint;
┌────────────────────────────┐
│            tint            │
│            tint            │
├────────────────────────────┤
│ 100@2025-01-01 05:00:00+00 │
└────────────────────────────┘

D SELECT duration('{1@2000-01-01, 2@2000-01-02, 1@2000-01-03}'::TINT, true) as duration;
┌──────────┐
│ duration │
│ interval │
├──────────┤
│ 2 days   │
└──────────┘

D SELECT tstzspan('[2000-01-01,2000-01-01]') as ts_span;
┌──────────────────────────────────────────────────┐
│                     ts_span                      │
│                       span                       │
├──────────────────────────────────────────────────┤
│ [2000-01-01 00:00:00+00, 2000-01-02 00:00:00+00) │
└──────────────────────────────────────────────────┘

D SELECT timeSpan(tgeompoint('{Point(1 1)@2000-01-01, Point(2 2)@2000-01-02, Point(1 1)@2000-01-03}')) as span;
┌──────────────────────────────────────────────────┐
│                       span                       │
│                       span                       │
├──────────────────────────────────────────────────┤
│ [2000-01-01 00:00:00+00, 2000-01-03 00:00:00+00] │
└──────────────────────────────────────────────────┘

D SELECT * FROM setUnnest(textset('{"highway", "car", "bike"}'));
┌─────────┐
│ unnest  │
│ varchar │
├─────────┤
│ bike    │
│ car     │
│ highway │
└─────────┘

4. Running the tests

Test files are located in ./test/sql. These SQL tests can be run using:

make test