Spatial database
A spatial database is a general-purpose database (usually a relational database) that has been enhanced to include spatial data that represents objects defined in a geometric space, along with tools for querying and analyzing such data. 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 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. The Open Geospatial Consortium (OGC) developed the Simple Features 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 SQL/MM multimedia standard and extends the Simple Features standard with data types that support circular interpolations. 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. Geographic database (or geodatabase) is a georeferenced spatial database, used for storing and manipulating geographic data (or geodata), i.e., data associated with a location on Earth. The term "geodatabase" may also refer specifically to a set of proprietary spatial database formats, Geodatabase (Esri). The core functionality add 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 (point, line, polygon, etc.) based on the vector data model. The datatypes in most spatial databases are based on the OGC Simple Features specification for representing geometric primitives.