(Geo)Parquet

Added in version 3.5.

Driver short name

Parquet

Build dependencies

Parquet component of the Apache Arrow C++ library

From https://parquet.apache.org/: "Apache Parquet is an open source, column-oriented data file format designed for efficient data storage and retrieval. It provides efficient data compression and encoding schemes with enhanced performance to handle complex data in bulk. Parquet is available in multiple languages including Java, C++, Python, etc..."

This driver also supports geometry columns using the GeoParquet specification.

The GeoParquet 1.0.0 specification is supported since GDAL 3.8.0. The GeoParquet 1.1.0 specification is supported since GDAL 3.9.0.

Driver capabilities

Supports Create()

This driver supports the GDALDriver::Create() operation

Supports Georeferencing

This driver supports georeferencing

Supports VirtualIO

This driver supports virtual I/O operations (/vsimem/, etc.)

Open options

Open options can be specified in command-line tools using the syntax -oo <NAME>=<VALUE> or by providing the appropriate arguments to GDALOpenEx() (C) or gdal.OpenEx (Python). The following open options are supported:

  • GEOM_POSSIBLE_NAMES=value: (GDAL >= 3.8) Defaults to geometry,wkb_geometry,wkt_geometry. Comma separated list of possible names for geometry column(s). Only used for files without GeoParquet dataset-level metadata. Columns are recognized as geometry columns only if they are of type binary (they are assumed to contain WKB encoded geometries), or if they are of type string and contain the "wkt" substring in their name (they are then assumed to contain WKT encoded geometries).

  • CRS=value: (GDAL >= 3.8) To set or override the CRS of geometry columns. The string is typically formatted as CODE:AUTH (e.g "EPSG:4326"), or can be a PROJ.4 or WKT CRS string.

  • LISTS_AS_STRING_JSON=[YES​/​NO]: (GDAL >= 3.12.1) Defaults to NO. Whether lists of strings/integers/reals should be reported as String(JSON) fields rather than String/Integer[64]/RealList. Useful when null values in such lists must be exactly mapped as such, instead of being omitted (for lists of strings), or set to 0 (for list of boolean, integer or real).

Creation issues

The driver supports creating only a single layer in a dataset.

Layer creation options

Layer creation options can be specified in command-line tools using the syntax -lco <NAME>=<VALUE> or by providing the appropriate arguments to GDALDatasetCreateLayer() (C) or Dataset.CreateLayer (Python). The following layer creation options are supported:

  • COMPRESSION=[NONE​/​UNCOMPRESSED​/​SNAPPY​/​GZIP​/​BROTLI​/​ZSTD​/​LZ4_RAW​/​LZ4_HADOOP]:

    Compression method. Available values depend on how the Parquet library was compiled. Defaults to SNAPPY when available, otherwise NONE.

  • COMPRESSION_LEVEL=<integer>: (GDAL >= 3.12) Specify the compression level for the selected compression method. The compression level has a different meaning for each codec. The description of this option, returned at runtime for example by ogrinfo --format PARQUET, gives the range and default value for each codec.

  • GEOMETRY_ENCODING=[WKB​/​WKT​/​GEOARROW​/​GEOARROW_INTERLEAVED]: Defaults to WKB. Geometry encoding. WKB is the default and recommended choice for maximal interoperability. WKT is not allowed by the GeoParquet specification, but are handled as an extension. As of GDAL 3.9, GEOARROW uses the GeoParquet 1.1 GeoArrow "struct" based encodings (where points are modeled as a struct field with a x and y subfield, lines are modeled as a list of such points, etc.). The GEOARROW_INTERLEAVED option has been renamed in GDAL 3.9 from what was named GEOARROW in previous versions, and uses an encoding where points uses a FixedSizedList of (x,y), lines a variable-size list of such FixedSizedList of points, etc. This GEOARROW_INTERLEAVED encoding is not part of the official GeoParquet specification, and its use is not encouraged.

  • ROW_GROUP_SIZE=<integer>: Defaults to 65536. Maximum number of rows per group.

  • GEOMETRY_NAME=value: Defaults to geometry. Name of geometry column.

  • FID=value: Name of the FID (Feature Identifier) column to create. If none is specified, no FID column is created. Note that if using ogr2ogr with the Parquet driver as the target driver and a source layer that has a named FID column, this FID column name will be automatically used to set the FID layer creation option of the Parquet driver (unless -lco FID= is used to set an empty name)

  • POLYGON_ORIENTATION=[COUNTERCLOCKWISE​/​UNMODIFIED]: Defaults to COUNTERCLOCKWISE. Whether exterior rings of polygons should be counterclockwise oriented (and interior rings clockwise oriented), or left to their original orientation.

  • EDGES=[PLANAR​/​SPHERICAL]: Defaults to PLANAR. How to interpret the edges of the geometries: whether the line between two points is a straight cartesian line (PLANAR) or the shortest line on the sphere (geodesic line) (SPHERICAL).

  • CREATOR=value: Name of creating application.

  • WRITE_COVERING_BBOX=[AUTO​/​YES​/​NO]: (GDAL >= 3.9) Defaults to AUTO. Whether to write xmin/ymin/xmax/ymax columns with the bounding box of geometries. Writing the geometry bounding box may help applications to perform faster spatial filtering. Writing a geometry bounding box is less necessary for the GeoArrow geometry encoding than for the default WKB, as implementations may be able to directly use the geometry columns.

    If the USE_PARQUET_GEO_TYPES layer creation option is set to ONLY, and WRITE_COVERING_BBOX is set or let to its default AUTO value, no covering bounding box columns is written.

  • USE_PARQUET_GEO_TYPES=[YES​/​NO​/​ONLY]: (GDAL >= 3.12) Defaults to NO. Only available with libarrow >= 21.

    Whether to use Parquet Geometry/Geography logical types (introduced in libarrow 21), when using the default GEOMETRY_ENCODING=WKB encoding.

    • YES: use the Geometry logical type (or the Geography one if the EDGES=SPHERICAL creation option is also set), and also write file-level GeoParquet metadata. Such files can be read by older GDAL, but require libarrow >= 20.

    • NO (default): only file-level GeoParquet metadata is written. Such files can be read by older GDAL and libarrow versions.

    • ONLY: use the Geometry logical type (or the Geography one if the EDGES=SPHERICAL creation option is also set), but do not write file-level GeoParquet metadata. Such files will only be fully compatible of GDAL >= 3.12 and libarrow >= 21. With libarrow 20, the geometry column of such files will only be recognized if it is among one of the GEOM_POSSIBLE_NAMES open option value, and the CRS of such files will not be recognized. With older libarrow, such files cannot be opened at all.

  • SORT_BY_BBOX=[YES​/​NO]: (GDAL >= 3.9) Defaults to NO. Whether features should be sorted based on the bounding box of their geometries, before being written in the final file. Sorting them enables faster spatial filtering on reading, by grouping together spatially close features in the same group of rows.

    Note however that enabling this option involves creating a temporary GeoPackage file (in the same directory as the final Parquet file), and thus requires temporary storage (possibly up to several times the size of the final Parquet file, depending on Parquet compression) and additional processing time.

    The efficiency of spatial filtering depends on the ROW_GROUP_SIZE. If it is too large, too many features that are not spatially close will be grouped together. If it is too small, the file size will increase, and extra processing time will be necessary to browse through the row groups.

    Note also that when this option is enabled, the Arrow writing API (which is for example triggered when using ogr2ogr to convert from Parquet to Parquet), fallbacks to the generic implementation, which does not support advanced Arrow types (lists, maps, etc.).

SQL support

SQL statements are run through the OGR SQL engine. Statistics can be used to speed-up evaluations of SQL requests like: "SELECT MIN(colname), MAX(colname), COUNT(colname) FROM layername"

Dataset/partitioning read support

Starting with GDAL 3.6.0, the driver can read directories that contain several Parquet files, and expose them as a single layer. This support is only enabled if the driver is built against the arrowdataset C++ library.

It is also possible to force opening single Parquet file in that mode by prefixing their filename with PARQUET:.

Optimized spatial and attribute filtering for Arrow datasets is available since GDAL 3.10.

Metadata

Added in version 3.9.0.

Layer metadata can be read and written. It is serialized as JSON content in a gdal:metadata domain.

Multithreading

Starting with GDAL 3.6.0, the driver will use up to 4 threads for reading (or the maximum number of available CPUs returned by CPLGetNumCPUs() if it is lower by 4). This number can be configured with the configuration option GDAL_NUM_THREADS, which can be set to an integer value or ALL_CPUS.

Update support

Added in version 3.12.0.

The driver supports adding, updating, removing features and fields. Note that this is accomplished by rewriting the whole file during GDALDataset::FlushCache() or when closing the dataset, and keeping into memory all modifications between two flushes.

If the file to be updated has been created by GDAL >= 3.12, the creation options to create the original file will be re-applied when creating the updated file. Stability of feature ids is only guaranteed if the original file has been created with an explicit FID creation option.

If the file to be updated has been created outside of GDAL, the original non-scalar/nested field types will not always be preserved, but a JSON representation may be used instead.

Validation script

The validate_geoparquet.py Python script can be used to check compliance of a Parquet file against the GeoParquet specification.

To validate only metadata:

python3 validate_geoparquet.py my_geo.parquet

To validate metadata and check content of geometry column(s):

python3 validate_geoparquet.py --check-data my_geo.parquet

Conda-forge package

The driver can be installed as a plugin for the libgdal conda-forge package with:

conda install -c conda-forge libgdal-arrow-parquet

Standalone plugin compilation

Added in version 3.10.

While this driver may be built as part of a whole GDAL build, either in libgdal itself, or as a plugin, it is also possible to only build this driver as a plugin, against an already built libgdal.

The version of the GDAL sources used to build the driver must match the version of the libgdal it is built against.

For example, from a "build_parquet" directory under the root of the GDAL source tree:

cmake -S ../ogr/ogrsf_frmts/parquet -DCMAKE_PREFIX_PATH=/path/to/GDAL_installation_prefix -DArrow_DIR=/path/to/lib/cmake/Arrow -DParquet_DIR=/path/to/lib/cmake/Parquet
cmake --build .

Note that such a plugin, when used against a libgdal not aware of it, will be systematically loaded at GDAL driver initialization time, and will not benefit from deferred plugin loading capabilities <rfc-96>. For that, libgdal itself must be built with the CMake variable OGR_REGISTER_DRIVER_PARQUET_FOR_LATER_PLUGIN=ON set.