geo-arrow-spec

Specifications for storing geospatial data in Apache Arrow and Apache Parquet.

The Apache Arrow project specifies a standardized language-independent columnar memory format. It enables shared computational libraries, zero-copy shared memory and streaming messaging, interprocess communication, etc and is supported by many programming languages. The Feather file format is an on-disk representation of this memory format.

Apache Parquet is an efficient, columnar storage format (originating from the Hadoop ecosystem). It is a widely used file format for tabular data, and its implementation for C-based languages (Python, R) is included in the Apache Arrow project.

Geospatial data often comes in tabular format, with one (or multiple) column with feature geometries and additional columns with feature attributes.

Defining a standard way to store geospatial data in the Arrow memory layout can help interoperability between different tools and enable fast data transfer:

• Ensure that different tools can read Parquet or Feather files with geospatial data and correctly interpret the geometry information. Concrete example: we want that the R sf package can read a parquet file produced by the Python geopandas package and vice versa.
• A standard in-memory specification for geometry data using the Arrow memory layout. This ensures geospatial data can be used in a growing number of applications that use the Arrow standard for in-memory data sharing or fast data transfer.

The goal of this repository is to discuss and move towards specifications on metadata and memory layout for storing geospatial data in the Arrow memory layout or related formats (Feather, Parquet).

Implementations

Parquet and Feather IO using standard metadata

• GeoPandas (Python)
• sfarrow (R)