Geodatabase
From Wikipedia, the free encyclopedia
A geodatabase is a database with extensions for storing, querying, and manipulating geographic information and spatial data.
The primary purpose of geodatabases is to store data about locations in the physical world as simple points and more complex objects and to allow users to query this data, for example to find all the residents of an area within an exposure zone for a potential environmental hazard.
Each geographical object (feature) in a geodatabase is composed of different parts: the geometry, the feature spatial reference system, a description (also known as the object's attributes) and, optionally, its behavior for 'intelligent' objects which include specialized functionality. The simplest object stored by a geodatabase is a point, and geodatabases combine points to make more complex vector data objects including lines, arcs and polygons.
Some of the geographic datasets comprising geodatabases include feature classes, attribute tables, relationship classes, domains, raster datasets, network datasets, topologies, and many others.
[edit] Vendors
An early development in storing spatial data in a modified relational database management system resulted in a modified Oracle v.4 during the late 1980s and early 1990s; this eventually led to the creation of Oracle Spatial.
The implementation of geodatabases for spatial information storage among common GIS users became widespread after ESRI released its first geodatabase solution as part of ArcGIS version 8 in 2001.[citation needed]
By the mid-2000s, geospatial data had the ability to be stored in a variety of commercial and open source spatially-enabled database management systems, such as Microsoft Access, PostgreSQL, SQL Server, MySQL and Oracle. It can be manipulated using extensions such as Oracle Spatial, PostGIS and ESRI's ArcGIS or ArcSDE.
Geodatabases can also be used to serve data directly to web map server software, such as ESRI's ArcGIS Internet Map Server, MapServer and Google's mapping API.
Storing geographic information in a geodatabase has numerous advantages over file-based data storage including the ability to generate complex geospatial queries.
Another significant advantage of an enterprise level geodatabase, such as ArcSDE or PostGIS, is the ability for multiple users to simultaneously view, edit, and query the database without conflict.
[edit] See also
[edit] Further reading
- ESRI Press.Modeling Our World: The ESRI Guide to Geodatabase Design
- Pro Oracle Spatial, 2004, Springer-Verlag, Ravi Kothuri, Albert Godfrind, and Euro Beinat.
- Designing Geodatabases: Case Studies in GIS Data Modeling , 2005 Ben Franklin Award winner, PMA, The Independent Book Publishers Association.
