Contents

• PostgreSQL bindings for H3
  • Prerequisites
  • Quick Overview
  • Manual Installation
  • h3_h3_to_children
  • Development
  • Usage
  • License

PostgreSQL bindings for H3

This library provides PostgreSQL bindings for the H3 Core Library. For API reference, please see the H3 Documentation.

Developed in collaboration with Scandinavian Highlands.

Prerequisites

• PostgreSQL 9.6 or higher (including server headers). It might work with earlier versions, we have not tested earlier than 9.6.
• C compiler (e.g., gcc)
• GNU Make
• H3

Quick Overview

If the prerequsites are met you can use the PGXN Client to download, build, and install, e.g.:

$ pgxn install h3 $ pgxn load -d mydb h3 $ psql -d mydb =# SELECT h3_geo_to_h3(POINT('37.3615593,-122.0553238'), 5);

Manual Installation

First, you must build H3.

git clone https://github.com/uber/h3.git cd h3 cmake -DCMAKE_C_FLAGS=-fPIC . make sudo make install

Then build h3-pg:

git clone ... cd h3-pg make sudo make install

Run psql and load/use extension in database:

``` CREATE_EXTENSION h3;

SELECT h3_h3_to_children('880326b88dfffff', 9);

h3_h3_to_children

890326b88c3ffff 890326b88c7ffff 890326b88cbffff 890326b88cfffff 890326b88d3ffff 890326b88d7ffff 890326b88dbffff ```

Development

We provide a Dockerfile for development without installation of H3 and Postgres. The following requires that your system has docker installed.

First, build the docker image:

docker build -t h3-pg .

Then, build the extension and run the test suite:

docker run --rm h3-pg

Afterwards, to quickly build and test changes, run:

chmod -R 777 . docker run --rm -it -v "$PWD":/tmp/h3-pg h3-pg

It will mount the code as a volume, and also mount the test output directory, so output can be inspected. The chmod might be needed if you get permission denied errors.

Usage

Generally all functions have been renamed from camelCase to snake_case with an added h3_ prefix. This means a few functions will have a double h3_h3_ prefix, but we chose this for consistency. For example h3ToChildren becomes h3_h3_to_children.

See API reference

License

This project is released under the Apache 2.0 License.