A spatial database is a general-purpose

database In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and a ...

(usually a

relational database A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A Relational Database Management System (RDBMS) is a type of database management system that stores data in a structured for ...

) that has been enhanced to include

spatial data Geographic data and information is defined in the ISO/TC 211 series of standards as data and information having an implicit or explicit association with a location relative to Earth (a geographic location or geographic position). It is also ca ...

that represents objects defined in a

geometric space Geometry (; ) is a branch of mathematics concerned with properties of space such as the distance, shape, size, and relative position of figures. Geometry is, along with arithmetic, one of the oldest branches of mathematics. A mathematician w ...

, along with tools for querying and analyzing such data. Most spatial databases allow the representation of simple geometric objects such as

points A point is a small dot or the sharp tip of something. Point or points may refer to: Mathematics * Point (geometry), an entity that has a location in space or on a plane, but has no extent; more generally, an element of some abstract topologica ...

, lines and

polygon In geometry, a polygon () is a plane figure made up of line segments connected to form a closed polygonal chain. The segments of a closed polygonal chain are called its '' edges'' or ''sides''. The points where two edges meet are the polygon ...

s. Some spatial databases handle more complex structures such as 3D objects, topological coverages, linear networks, and triangulated irregular networks (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. Geographic database (or geodatabase) is a

georeferenced Georeferencing or georegistration is a type of coordinate transformation that binds a digital raster image or vector database that represents a geographic space (usually a scanned map or aerial photograph) to a spatial reference system, thus loca ...

spatial database, used for storing and manipulating geographic data (or geodata, i.e., data associated with a location on Earth), especially in

geographic information systems A geographic information system (GIS) consists of integrated computer hardware and software that store, manage, analyze, edit, output, and visualize geographic data. Much of this often happens within a spatial database; however, this is not ...

(GIS). Almost all current relational and object-relational database management systems now have spatial extensions, and some GIS software vendors have developed their own spatial extensions to database management systems. The

Open Geospatial Consortium The Open Geospatial Consortium (OGC) is an international voluntary consensus standards organization that develops and maintains international standards for geospatial content and location-based services, sensor web, Internet of Things, Geographi ...

(OGC) developed the ''

Simple Features Simple Features (officially Simple Feature Access) is a set of standards that specify a common storage and access model of geographic features made of mostly two-dimensional geometries (point, line, polygon, multi-point, multi-line, etc.) used by ...

'' specification (first released in 1997) and sets standards for adding spatial functionality to database systems. The ''SQL/MM Spatial'' ISO/IEC standard is a part of the structured query language and multimedia standard extending the Simple Features.

Characteristics

The core functionality added by a spatial extension to a database is one or more ''spatial datatypes'', which allow for the storage of spatial data as attribute values in a table. Most commonly, a single spatial value would be a

geometric primitive In vector computer graphics, CAD systems, and geographic information systems, a geometric primitive (or prim) is the simplest (i.e. 'atomic' or irreducible) geometric shape that the system can handle (draw, store). Sometimes the subroutines ...

(point, line, polygon, etc.) based on the vector data model. The datatypes in most spatial databases are based on the OGC

specification for representing geometric primitives. Some spatial databases also support the storage of

raster data upright=1, The Smiley, smiley face in the top left corner is a raster image. When enlarged, individual pixels appear as squares. Enlarging further, each pixel can be analyzed, with their colors constructed through combination of the values for ...

. Because all geographic locations must be specified according to a

spatial reference system A spatial reference system (SRS) or coordinate reference system (CRS) is a framework used to precisely measure locations on the surface of Earth as coordinates. It is thus the application of the abstract mathematics of coordinate systems and anal ...

, spatial databases must also allow for the tracking and transformation of coordinate systems. In many systems, when a spatial column is defined in a table, it also includes a choice of coordinate system, chosen from a list of available systems that is stored in a lookup table. The second major functionality extension in a spatial database is the addition of spatial capabilities to the query language (e.g.,

SQL Structured Query Language (SQL) (pronounced ''S-Q-L''; or alternatively as "sequel") is a domain-specific language used to manage data, especially in a relational database management system (RDBMS). It is particularly useful in handling s ...

); these give the spatial database the same query, analysis, and manipulation operations that are available in traditional GIS software. In most relational database management systems, this functionality is implemented as a set of new functions that can be used in SQL SELECT statements. Several types of operations are specified by the

standard: *Measurement: Computes line length, polygon area, the distance between geometries, etc. *Geoprocessing: Modify existing features to create new ones, for example by creating a buffer around them, intersecting features, etc. *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?' (see

DE-9IM The Dimensionally Extended 9-Intersection Model (DE-9IM) is a topological Interpretation (logic), model and a Specification (technical standard), standard used to describe the spatial relations of two regions (two 2D geometric model, geometries ...

) *Geometry Constructors: Creates new geometries, usually by specifying the vertices (points or nodes) which define the shape. *Observer Functions: Queries that return specific information about a feature, such as the location of the center of a circle. Some databases support only simplified or modified sets of these operations, especially in cases of

NoSQL NoSQL (originally meaning "Not only SQL" or "non-relational") refers to a type of database design that stores and retrieves data differently from the traditional table-based structure of relational databases. Unlike relational databases, which ...

systems like

MongoDB MongoDB is a source-available, cross-platform, document-oriented database program. Classified as a NoSQL database product, MongoDB uses JSON-like documents with optional database schema, schemas. Released in February 2009 by 10gen (now MongoDB ...

and

CouchDB Apache CouchDB is an open-source document-oriented NoSQL database, implemented in Erlang. CouchDB uses multiple formats and protocols to store, transfer, and process its data. It uses JSON to store data, JavaScript as its query language using ...

Spatial index

A spatial index is used by a spatial database to optimize spatial queries, implementing spatial access methods. Database systems use indices to quickly look up values by sorting data values in a linear (e.g. alphabetical) order; however, this way of indexing data is not optimal for spatial queries in two- or three-dimensional space. Instead, spatial databases use a ''spatial'' index designed specifically for multi-dimensional ordering. Common spatial index methods include: *

Binary space partitioning In computer science, binary space partitioning (BSP) is a method for space partitioning which recursively subdivides a Euclidean space into two convex sets by using hyperplanes as partitions. This process of subdividing gives rise to a representa ...

(BSP-Tree): Subdividing space by hyperplanes. *

Bounding volume hierarchy A bounding volume hierarchy (BVH) is a tree structure on a set of geometric objects. All geometric objects, which form the leaf nodes of the tree, are wrapped in bounding volumes. These nodes are then grouped as small sets and enclosed within lar ...

(BVH) *

Geohash Geohash is a public domain geocode system invented in 2008 by Gustavo Niemeyer * * * which encodes a geographic location into a short string of letters and digits. Similar ideas were introduced by G.M. Morton in 1966. It is a hierarchical spat ...

Grid (spatial index) In the context of a spatial index, a grid or mesh is a regular tessellation of a manifold or 2-D surface that divides it into a series of contiguous cells, which can then be assigned unique identifiers and used for spatial indexing purposes. A ...

HHCode A Helical Hyperspatial Code, also known as an HHCode, is a data storage format for very large spatio-temporal datasets. The development of HHCode can be traced to efforts in the 1990's by Edric Keighan, Panagiotis A. Vretanos, Michael Galluchon, ...

Hilbert R-tree Hilbert R-tree, an R-tree variant, is an index for multidimensional objects such as lines, regions, 3-D objects, or high-dimensional feature-based parametric objects. It can be thought of as an extension to B+-tree for multidimensional objects. T ...

* ''k''-d 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. *

Octree An octree is a tree data structure in which each internal node has exactly eight child node, children. Octrees are most often used to partition a three-dimensional space by recursive subdivision, recursively subdividing it into eight Octant (geo ...

* PH-tree *

Quadtree A quadtree is a tree data structure in which each internal node has exactly four children. Quadtrees are the two-dimensional analog of octrees and are most often used to partition a two-dimensional space by recursively subdividing it into four ...

R-tree R-trees are tree data structures used for spatial access methods, i.e., for indexing multi-dimensional information such as geographical coordinates, rectangles or polygons. The R-tree was proposed by Antonin Guttman in 1984 and has found s ...

: Typically the preferred method for indexing spatial data. Objects (shapes, lines and points) are grouped using the

minimum bounding rectangle In computational geometry, the minimum bounding rectangle (MBR), also known as bounding box (BBOX) or envelope, is an expression of the maximum extents of a two-dimensional object (e.g. point, line, polygon) or set of objects within its coord ...

(MBR). Objects are added to an MBR within the index that will lead to the smallest increase in its size. *

R+ tree R-trees are tree data structures used for spatial index, spatial access methods, i.e., for indexing multi-dimensional information such as Geographic coordinate system, geographical coordinates, rectangles or polygons. The R-tree was proposed ...

* R* tree * UB-tree *

X-tree In computer science tree data structures, an X-tree (for ''eXtended node tree'') is an index tree structure based on the R-tree used for storing data in many dimensions. It appeared in 1996, and differs from R-trees (1984), R+-trees (1987) and ...

* Z-order (curve)

Spatial query

A spatial query is a special type of

database query In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and analy ...

supported by spatial databases, including geodatabases. The queries differ from non-spatial

queries in several important ways. Two of the most important are that they allow for the use of geometry data types such as points, lines and polygons and that these queries consider the spatial relationship between these geometries. The function names for queries differ across geodatabases. The following are a few of the functions built into

PostGIS PostGIS ( ) is an open source software program that adds support for geographic objects to the PostgreSQL object-relational database. PostGIS follows the Simple Features for SQL specification from the Open Geospatial Consortium (OGC). PostGIS is ...

, a free geodatabase which is a PostgreSQL extension (the term 'geometry' refers to a point, line, box or other two or three dimensional shape): Function prototype: ''functionName (parameter(s)) : return type '' * ST_Distance(geometry, geometry) : number * ST_Equals(geometry, geometry) : boolean * ST_Disjoint(geometry, geometry) : boolean * ST_Intersects(geometry, geometry) : boolean * ST_Touches(geometry, geometry) : boolean * ST_Crosses(geometry, geometry) : boolean * ST_Overlaps(geometry, geometry) : boolean * ST_Contains(geometry, geometry) : boolean * ST_Length(geometry) : number * ST_Area(geometry) : number * ST_

Centroid In mathematics and physics, the centroid, also known as geometric center or center of figure, of a plane figure or solid figure is the arithmetic mean position of all the points in the figure. The same definition extends to any object in n-d ...

(geometry) : geometry * ST_Intersection(geometry, geometry) : geometry Thus, a spatial join between a points layer of cities and a polygon layer of countries could be performed in a spatially-extended SQL statement as: SELECT * FROM cities, countries WHERE ST_Contains(countries.shape, cities.shape) The Intersect vector overlay operation (a core element of GIS software) could be replicated as:

SELECT ST_Intersection(veg.shape, soil.shape) int_poly, veg.*, soil.* FROM veg, soil where ST_Intersects(veg.shape, soil.shape)

Spatial database management systems

List

* AllegroGraph – a

graph database A graph database (GDB) is a database that uses graph structures for semantic queries with nodes, edges, and properties to represent and store data. A key concept of the system is the graph (or edge or relationship). The graph relates the dat ...

which provides a mechanism for efficient storage and retrieval of two-dimensional geospatial coordinates for

Resource Description Framework The Resource Description Framework (RDF) is a method to describe and exchange graph data. It was originally designed as a data model for metadata by the World Wide Web Consortium (W3C). It provides a variety of syntax notations and formats, of whi ...

data. It includes an extension syntax for

SPARQL SPARQL (pronounced ":wikt:sparkle, sparkle", a recursive acronym for SPARQL Protocol and RDF Query Language) is an RDF query language—that is, a Semantic Query, semantic query language for databases—able to retrieve and manipulate data sto ...

queries. *

ArangoDB ArangoDB is a graph database system developed by ArangoDB Inc. ArangoDB is a multi-model database system since it supports three data models (graphs, JSON documents, key/value) with one database core and a unified query language AQL (ArangoDB Qu ...

- a multi-model database which provides geoindexing capability. * Apache Drill - A MPP SQL query engine for querying large datasets. Drill supports spatial data types and functions similar to PostgreSQL. * Esri Geodatabase (Enterprise, Mobile) - a proprietary spatial database structure and logical model that can be implemented on several relational databases, both commercial (Oracle, MS SQL Server, Db2) and open source (PostgreSQL, SQLite) *

Caliper Calipers or callipers are an instrument used to measure the linear dimensions of an object or hole; namely, the length, width, thickness, diameter or depth of an object or hole. The word "caliper" comes from a corrupt form of caliber. Many ty ...

extends the Raima Data Manager with spatial datatypes, functions, and utilities. *

a document-based database system that can be spatially enabled by a plugin called Geocouch *

Elasticsearch Elasticsearch is a Search engine (computing), search engine based on Apache Lucene, a free and open-source search engine. It provides a distributed, Multitenancy, multitenant-capable full-text search engine with an HTTP web interface and schema ...

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 Apache Accumulo is a highly scalable sorted, distributed key-value store based on Google's Bigtable. It is a system built on top of Apache Hadoop, Apache ZooKeeper, and Apache Thrift. Written in Java, Accumulo has cell-level access labels and ...

and

Apache Hadoop Apache Hadoop () is a collection of open-source software utilities for reliable, scalable, distributed computing. It provides a software framework for distributed storage and processing of big data using the MapReduce programming model. Hadoop wa ...

(also supports

Apache HBase HBase is an open-source non-relational distributed database modeled after Google's Bigtable and written in Java. It is developed as part of Apache Software Foundation's Apache Hadoop project and runs on top of HDFS (Hadoop Distributed Fil ...

Google Google LLC (, ) is an American multinational corporation and technology company focusing on online advertising, search engine technology, cloud computing, computer software, quantum computing, e-commerce, consumer electronics, and artificial ...

Bigtable Bigtable is a fully managed wide-column and key-value NoSQL database service for large analytical and operational workloads as part of the Google Cloud portfolio. History Bigtable development began in 2004.. It is now used by a number of Goo ...

Apache Cassandra Apache Cassandra is a free and open-source software, free and open-source database management system designed to handle large volumes of data across multiple Commodity computing, commodity servers. The system prioritizes availability and scalab ...

, and

Apache Kafka Apache Kafka is a distributed event store and stream-processing platform. It is an open-source system developed by the Apache Software Foundation written in Java and Scala. The project aims to provide a unified, high-throughput, low-latency pl ...

). GeoMesa supports full OGC

and a GeoServer plugin. * H2 supports geometry types and spatial indices as of version 1.3.173 (2013-07-28). An extension called H2GIS available on Maven Central gives full OGC

support. * Any edition of IBM Db2 can be spatially-enabled to implement the OpenGIS spatial functionality with SQL spatial types and functions. *

IBM Informix Informix is a product family within IBM's Information Management division that is centered on several relational database management system (RDBMS) and multi-model database offerings. The Informix products were originally developed by Infor ...

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 Microsoft SQL Server is a proprietary relational database management system developed by Microsoft using Structured Query Language (SQL, often pronounced "sequel"). As a database server, it is a software product with the primary function of ...

has support for spatial types since version 2008 * MonetDB/GIS extension for

MonetDB MonetDB is an open-source column-oriented relational database management system (RDBMS) originally developed at the Centrum Wiskunde & Informatica (CWI) in the Netherlands. It is designed to provide high performance on complex queries against l ...

adds OGS Simple Features to the relational column-store database. *

MySQL MySQL () is an Open-source software, open-source relational database management system (RDBMS). Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, and "SQL", the acronym for Structured Query Language. A rel ...

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 Neo4j is a graph database management system (GDBMS) developed by Neo4j Inc. The data elements Neo4j stores are nodes, edges connecting them, and attributes of nodes and edges. Described by its developers as an ACID-compliant transactional d ...

– a

that can build 1D and 2D indexes as

B-tree In computer science, a B-tree is a self-balancing tree data structure that maintains sorted data and allows searches, sequential access, insertions, and deletions in logarithmic time. The B-tree generalizes the binary search tree, allowing fo ...

and

Hilbert curve The Hilbert curve (also known as the Hilbert space-filling curve) is a Geometric continuity, continuous fractal curve, fractal space-filling curve first described by the German mathematician David Hilbert in 1891, as a variant of the space-filling ...

directly in the

graph Graph may refer to: Mathematics *Graph (discrete mathematics), a structure made of vertices and edges **Graph theory, the study of such graphs and their properties *Graph (topology), a topological space resembling a graph in the sense of discret ...

* OpenLink Virtuoso has supported SQL/MM since version 6.01.3126, with significant enhancements including

GeoSPARQL GeoSPARQL is a model for representing and querying geospatial linked data for the Semantic Web. It is standardized by the Open Geospatial Consortium as OGC GeoSPARQL. The definition of a small ontology based on well-understood OGC standards is inte ...

in Open Source Edition 7.2.6, and in Enterprise Edition 8.2.0 *

Oracle Spatial Oracle Spatial and Graph, formerly Oracle Spatial, is a free option component of the Oracle Database. The spatial features in Oracle Spatial and Graph aid users in managing geographic and location-data in a native type within an Oracle database, p ...

PostgreSQL PostgreSQL ( ) also known as Postgres, is a free and open-source software, free and open-source relational database management system (RDBMS) emphasizing extensibility and SQL compliance. PostgreSQL features transaction processing, transactions ...

DBMS (database management system) uses the extension

to implement OGC-compliant spatial functionality, including standardized datatype ''geometry'' and corresponding functions. *

Redis Redis (; Remote Dictionary Server) is an in-memory key–value database, used as a distributed cache and message broker, with optional durability. Because it holds all data in memory and because of its design, Redis offers low- latency reads ...

with the Geo API. * RethinkDB supports geospatial indexes in 2D. *

SAP HANA SAP HANA (HochleistungsANalyseAnwendung or High-performance ANalytic Application) is an in-memory, column-oriented, relational database management system developed and marketed by SAP SE. Its primary function as the software running a datab ...

supports geospatial with SPS08. * Smallworld VMDS, the native GE Smallworld GIS database
SpaceTime
is a commercial spatiotemporal database built on top of the proprietary multidimensional index similar to the ''k''-d tree family, but created using the bottom-up approach and adapted to particular space-time distribution of data. * Spatial Query Server from

Boeing The Boeing Company, or simply Boeing (), is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, and missiles worldwide. The company also provides leasing and product support s ...

spatially enables Sybase ASE. *

SpatiaLite SpatiaLite is a spatial extension to SQLite, providing vector geodatabase functionality. It is similar to PostGIS, Oracle Spatial, and SQL Server with spatial extensions, although SQLite/SpatiaLite aren't based on client-server architecture: th ...

extends

Sqlite SQLite ( "S-Q-L-ite", "sequel-ite") is a free and open-source relational database engine written in the C programming language. It is not a standalone app; rather, it is a library that software developers embed in their apps. As such, it ...

with spatial datatypes, functions, and utilities. *

Tarantool Tarantool is an in-memory computing platform with a flexible data schema, best used for creating high-performance applications. Two main parts of it are an in-memory database and a Lua application server. Tarantool maintains data in memory and ...

supports geospatial queries with RTREE index. * Teradata Geospatial includes 2D spatial functionality (OGC-compliant) 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

Notes

References

External links

An introduction to PostgreSQL PostGIS
SOA
A Trigger Based Security Alarming Scheme for Moving Objects on Road Networks
Sajimon Abraham, P. Sojan Lal, Published by Springer Berlin / Heidelberg-2008.

ArcGIS Resource Center description of a geodatabase {{Authority control Geometric algorithms