Export an indexed FlatGeobuf file

A runnable Apache Hop tutorial for FlatGeobuf.

All vector examples · Vector Raster plugin

Export the three sites into one indexed FlatGeobuf file for downstream tools that support the format.

Before you begin

Download and set up the example project. This walkthrough uses Apache Hop 2.19.0, distribution 0.2.1-SNAPSHOT.build.35761791293.1, with the local run configuration. Keep the supplied input unchanged and use a writable output directory.

Download flatgeobuf.hpl · Complete project ZIP

The individual pipeline requires the data and project configuration from the complete ZIP.

The FlatGeobuf pipeline in Hop GUI.

The FlatGeobuf pipeline in Hop GUI.

Read the source

  1. Open flatgeobuf.hpl from the example project.
  2. Click Read vector and choose Edit. The file is ${PROJECT_HOME}/data/sites.gpkg, format AUTO, layer sites, and geometry output field geometry.
  3. Use the source schema/preview controls to inspect the fields. Expect site_id, name, height_m and a geometry field. The source contains three point features in EPSG:2056.
  4. Close the reader dialog with OK, then click the writer and choose Edit.

Vector Reader configured for the supplied GeoPackage layer.

Vector Reader configured for the supplied GeoPackage layer.

Configure the writer

Setting Value
Format FLATGEOBUF
Output file ${PROJECT_HOME}/output/sites.fgb
Geometry field geometry
Layer geometry type POINT
Layer dimension XY
Assign CRS EPSG:2056
Spatial index (reorders features) On
Skip NULL/EMPTY geometries with warning Off
Overwrite existing file Off

Vector Writer settings for FlatGeobuf.

Vector Writer settings for FlatGeobuf.

Run and check the result

Save and run flatgeobuf.hpl. Expect one .fgb file containing three XY point features with all three attributes. Check the result by matching site_id, rather than comparing row positions: the spatial index can reorder features.

Open the output in a FlatGeobuf-capable GIS or inspect it with ogrinfo -al output/sites.fgb if GDAL is installed. GDAL is an optional independent checker; it is not required by GeoHop. Vector Reader cannot read this format in the documented distribution.

Completed FlatGeobuf pipeline with processing metrics.

Completed FlatGeobuf pipeline with processing metrics.

Things to watch out for

  • Indexed output rejects NULL/EMPTY geometries by default. Turning on the skip option drops those rows with a warning; reconcile the output count if you choose it.
  • Disabling the spatial index preserves input order. Index creation can require substantial memory and temporary disk space for larger datasets.
  • Select an explicit geometry type and dimension for empty input instead of depending on schema inference.
  • Supported curve inputs are linearized for this output. The tutorial’s plain XY points do not exercise curve or Z/M behaviour.
  • Do not connect this file to Vector Reader for a roundtrip: this format is output-only here.

The CRS controls assign a coordinate reference system; they do not reproject coordinates. All coordinates in this example already use EPSG:2056.

Further reading