This page lists GeoPackage extensions that are not currently part of the GeoPackage Encoding Standard. Often these are developed outside of OGC. It is often preferable to use an existing extension (even if it is proprietary) instead of developing your own. Extensions that have widespread adoption will be considered for OGC approval.
To publish a new extension, fill out the extension template and let us know on the GeoPackage Mailing List.
- Related Tables
- This extension provides a mechanism for associating tables with existing feature or attribute tables in a GeoPackage. Among other things, it can be used to establish a many-to-many relationship between features and multimedia files. It was originally developed by Compusult and the plan is to test it during an upcoming OGC Interoperability Experiment.
- OWS Context
- The main goal of the extension is to store context and styling of a mapping project as part of a GeoPackage file containing the data it refers to. The extension aims at similar use cases as presented in The USGS GeoPackage Styling Experiment in Testbed 12, however the approach is a bit different.
- QGIS Map Styling Information
- This extension stores QGIS projects with their resources like images in print templates in a GeoPackage file.
- Feature Tile Link
- This extension creates a link between a feature and tile table. A tile table containing tiles that represent or were generated from features can be linked to the feature table. The link enables feature queries when dealing with tiles representing features.
- Geometry Index
- This extension defines a SQLite version agnostic way to index user feature table geometries by their bounding envelopes for fast ranged searches. Mobile implementations, including Android and iOS, use earlier versions of SQLite and can not rely on the R*Tree Module implementation. Each geometry in a feature table is indexed by it's geometry id and x, y, z, and m value ranges. The geometry index can be queried for fast retrieval of only geometries overlapping a desired envelope bounds.
- Aspatial Support (Legacy)
- Support for aspatial data (ie. SQLite tables/views without a geometry column), potentially with associated metadata. This was used in GDAL 2.0 and GDAL 2.1, before the introduction of the 'attributes' data_type of GeoPackage v1.2. Starting with GDAL 2.2, 'attributes' will be used by default instead.
- Tiled Gridded Elevation Data Extension (Draft)
- Defines the rules for encoding and storing 16-bit and 32-bit tiled regular grid coverages composed of regular gridded data, such as elevation. This extension is currently under revision and this document is scheduled to be updated in August 2017.
- User Defined Geometry Types (Deprecated)
- Enables encoding of additional user-defined geometry types in ExtendedGeoPackageBinary format in an Extended GeoPackage. Removed from GeoPackage 1.2 due to interoperability reasons.
- Geometry Type Triggers (Deprecated)
- Geometry type triggers prevent the storage of geometries of types that are not assignable from the geometry types specified in the gpkg_geometry_columns table in the geometry columns of the specified tables. Removed from GeoPackage 1.2 due to interoperability reasons.
- Geometry SRS ID Triggers (Deprecated)
- Geometry SRS_ID triggers prevent the storage of geometries with spatial reference system identifiers that are not specified in the gpkg_geometry_columns table in the geometry columns of the specified tables. Removed from GeoPackage 1.2 due to interoperability reasons.