A GeoPackage is an open, standards-based, platform-independent, portable, self-describing, compact format for transferring geospatial information. It is a platform-independent SQLite [I5] database file that contains the GeoPackage data and metadata tables shown in Figure 1 below.
The GeoPackage Encoding Standard (this document) describes a set of conventions for storing the following within an SQLite database:
-
vector features;
-
tile matrix sets of imagery and raster maps at various scales;
-
attributes (non-spatial data); and
-
extensions.
These conventions include table definitions, integrity assertions, format limitations, and content constraints. The required and supported content of a GeoPackage is entirely defined in the standard. These capabilities are built on a common base and the extension mechanism provides implementors a way to include additional functionality in their GeoPackages.
Since a GeoPackage is a database container, it supports direct use. This means that the data in a GeoPackage can be accessed and updated in a "native" storage format without intermediate format translations. GeoPackages that comply with the requirements in the standard and do not implement vendor-specific extensions are interoperable across all enterprise and personal computing environments. GeoPackages are particularly useful on mobile devices such as cell phones and tablets in communications environments where there is limited connectivity and bandwidth.Mobile device users who require map/geospatial application services and operate in disconnected or limited network connectivity environments are challenged by limited storage capacity and the lack of open format geospatial data to support these applications.
This standard is intended to facilitate widespread adoption and use of GeoPackages by both COTS and open-source software applications on enterprise production platforms as well as mobile hand-held devices [B1] [B2], given that mobile hand held devices do not yet have the processing power or battery life to effectively tackle difficult geospatial product production and analysis tasks.
An Extended GeoPackage is a GeoPackage that contains any additional data elements (tables or columns) or SQL constructs (views, data types, functions, indexes, constraints or triggers) that are not automatically maintained within the SQLite data file or that result in a change in behavior not specified in this encoding standard.
A GeoPackage MAY be "empty" (contain user data table(s) for vector features, non-spatial attributes, and/or tile matrix pyramids with no row record content) or contain one or many vector feature type records and /or one or many tile matrix pyramid tile images. GeoPackage metadata CAN describe GeoPackage data contents and identify external data synchronization sources and targets. A GeoPackage MAY contain spatial indexes on feature geometries and SQL triggers to maintain indexes and enforce content constraints.
A GeoPackage SQLite Configuration consists of the SQLite 3 software library and a set of compile- and runtime configurations options.
A GeoPackage SQLite Extension is a SQLite loadable extension that MAY provide SQL functions [I12] to support spatial indexes and SQL triggers linked to a SQLite library with specified configuration requirements to provide SQL API [I1] [I2] [I3] [I4] access to a GeoPackage file. This standard does not address the issues listed in the [_potential_future_work] clause in [background_and_context], which MAY be addressed in a subsequent version of this standard or by other specifications.
