GeoParquet Class

The geometries are read as WellKnownBinary reads them, with their altitudes (Z) and measures (M). A null or empty geometry gives a feature without geometry. The geometry columns encoded with the native (GeoArrow) encodings throw a FormatException. The coordinate system of the column is not read: the coordinates are expected to be longitudes and latitudes (OGC:CRS84, the default of GeoParquet), and are not converted otherwise.

The properties are the other top-level columns, with the .NET type of the column, such as an Int32, a Int64, a Double, a String, a DateTime or an array of bytes. A null value is not a property. The columns of structures, lists and maps, such as the bbox covering column, are not read. The features have no identifier.

The Parquet files are read without dependency: the pages of versions 1 and 2, with the PLAIN, dictionary, RLE, delta and BYTE_STREAM_SPLIT encodings, uncompressed or compressed with Snappy, GZIP, Brotli, LZ4 or Zstandard. Zstandard needs .NET 11 or later: on .NET 10, such a file throws a NotSupportedException, as do LZO, encrypted files and column chunks stored in other files.

The file is read one row group at a time: the memory holds the columns of a row group, not the whole file. With GeoParquetReaderOptions.Bounds, the row groups whose bbox covering statistics are outside of the box are skipped.