Spatial database
A spatial database is a database that is optimized for storing and querying data that represents objects defined in a geometric space. Most spatial databases allow the representation of simple geometric objects such as points, lines and polygons. Some spatial databases handle more complex structures such as 3D objects, topological coverages, linear networks, and TINs. While typical databases have developed to manage various numeric and character types of data, such databases require additional functionality to process spatial data types efficiently, and developers have often added geometry or feature data types. The Open Geospatial Consortium developed the Simple Features specification and sets standards for adding spatial functionality to database systems. The SQL/MM Spatial ISO/IEC standard is a part the SQL/MM multimedia standard and extends the Simple Features standard with data types that support circular interpolations.
Geodatabase
A geodatabase is a database of geographic data, such as countries, administrative divisions, cities, and related information. Such databases can be useful for websites that wish to identify the locations of their visitors for customization purposes.Characteristics
Database systems use indexes to quickly look up values; however, this way of indexing data is not optimal for spatial queries. Instead, spatial databases use a spatial index to speed up database operations.In addition to typical SQL queries such as SELECT statements, spatial databases can perform a wide variety of spatial operations. The following operations and many more are specified by the Open Geospatial Consortium standard:
- Spatial Measurements: Computes line length, polygon area, the distance between geometries, etc.
- Spatial Functions: Modify existing features to create new ones, for example by providing a buffer around them, intersecting features, etc.
- Spatial Predicates: Allows true/false queries about spatial relationships between geometries. Examples include "do two polygons overlap" or 'is there a residence located within a mile of the area we are planning to build the landfill?'
- Geometry Constructors: Creates new geometries, usually by specifying the vertices which define the shape.
- Observer Functions: Queries which return specific information about a feature such as the location of the center of a circle
Spatial index
Spatial indices are used by spatial databases to optimize spatial queries. Conventional index types do not efficiently handle spatial queries such as how far two points differ, or whether points fall within a spatial area of interest. Common spatial index methods include:- Geohash
- HHCode
- Grid
- Z-order
- Quadtree
- Octree
- UB-tree
- R-tree: Typically the preferred method for indexing spatial data. Objects are grouped using the minimum bounding rectangle. Objects are added to an MBR within the index that will lead to the smallest increase in its size.
- R+ tree
- R* tree
- Hilbert R-tree
- X-tree
- kd-tree
- m-tree – an m-tree index can be used for the efficient resolution of similarity queries on complex objects as compared using an arbitrary metric.
- Binary space partitioning : Subdividing space by hyperplanes.
Spatial database systems
List
- AllegroGraph – a graph database which provides a mechanism for efficient storage and retrieval of two-dimensional geospatial coordinates for Resource Description Framework data. It includes an extension syntax for SPARQL queries.
- Caliper extends the Raima Data Manager with spatial datatypes, functions, and utilities.
- CouchDB a document-based database system that can be spatially enabled by a plugin called Geocouch
- Elasticsearch is a document-based database system that supports two types of geo data: geo_point fields which support lat/lon pairs, and geo_shape fields, which support points, lines, circles, polygons, multi-polygons, etc.
- GeoMesa is a cloud-based spatio-temporal database built on top of Apache Accumulo and Apache Hadoop. GeoMesa supports full OGC Simple Features and a GeoServer plugin.
- H2 supports geometry types and spatial indices as of version 1.3.173. An extension called H2GIS available on Maven Central gives full OGC Simple Features support.
- IBM DB2 Spatial Extender can spatially-enable any edition of DB2, including the free DB2 Express-C, with support for spatial types
- IBM Informix Geodetic and Spatial datablade extensions auto-install on use and expand Informix's datatypes to include multiple standard coordinate systems and support for RTree indexes. Geodetic and Spatial data can also be incorporated with Informix's Timeseries data support for tracking objects in motion over time.
- Linter SQL Server supports spatial types and spatial functions according to the OpenGIS specifications.
- Microsoft SQL Server has support for spatial types since version 2008
- MonetDB/GIS extension for MonetDB adds OGS Simple Features to the relational column-store database.
- MySQL DBMS implements the datatype geometry, plus some spatial functions implemented according to the OpenGIS specifications. However, in MySQL version 5.5 and earlier, functions that test spatial relationships are limited to working with minimum bounding rectangles rather than the actual geometries. MySQL versions earlier than 5.0.16 only supported spatial data in MyISAM tables. As of MySQL 5.0.16, InnoDB, NDB, BDB, and ARCHIVE also support spatial features.
- Neo4j – a graph database that can build 1D and 2D indexes as B-tree, Quadtree and Hilbert curve directly in the graph
- OpenLink Virtuoso has supported SQL/MM since version 6.01.3126, with significant enhancements including GeoSPARQL in Open Source Edition 7.2.6, and in Enterprise Edition 8.2.0
- Oracle Spatial
- PostgreSQL DBMS uses the spatial extension PostGIS to implement the standardized datatype geometry and corresponding functions.
- Redis with the Geo API.
- RethinkDB supports geospatial indexes in 2D.
- SAP HANA supports geospatial with SPS08.
- Smallworld VMDS, the native GE Smallworld GIS database
- Spatial Query Server from Boeing spatially enables Sybase ASE.
- SpatiaLite extends Sqlite with spatial datatypes, functions, and utilities.
- Tarantool supports geospatial queries with RTREE index.
- Teradata Geospatial includes 2D spatial functionality in its data warehouse system.
- Vertica Place, the geo-spatial extension for HP Vertica, adds OGC-compliant spatial features to the relational column-store database.
Table of free systems especially for spatial data processing
| DBS | License | Distributed | Spatial objects | Spatial functions | PostgreSQL interface | UMN MapServer interface | Documentation | Modifiable | HDFS |
| GeoMesa | Apache License 2.0 | yes | yes | yes | no | no | parts of the functions, a few examples | with Simple Feature Access in Java Virtual Machine and Apache Spark are all kinds of tasks solvable | yes |
| H2 | LGPL 3, GPL 3 before | no | yes | Simple Feature Access and custom functions for H2Network | yes | no | yes | SQL | no |
| Ingres | GPL or proprietary | yes | yes | Geometry Engine, Open Source | no | with MapScript | just briefly | with C and OME | no |
| Neo4J-spatial | GNU affero general public license | no | yes | yes | no | no | just briefly | fork of JTS | no |
| PostgreSQL with PostGIS | GNU General Public License | no | yes | yes | yes | yes | detailed | SQL, in connection with R | no |
| Postgres-XL with PostGIS | Mozilla public license and GNU general public license | yes | yes | yes | yes | yes | PostGIS: yes, Postgres-XL: briefly | SQL, in connection with R or Tcl or Python | no |
| Rasdaman | server GPL, client LGPL, enterprise proprietary | yes | just raster | raster manipulation with rasql | yes | with Web Coverage Service or Web Processing Service | detailed wiki | own defined function in enterprise edition | no |
| RethinkDB | AGPL | yes | yes |
| no | no | official documentation | forking | no |