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The origin of the geodatabase was in the mid-1990s during the emergence of the first spatial databases.One early approach to integrating relational databases and GIS was the use of server middleware, a third-party program that stores the spatial data in database tables in a custom format, and translates it dynamically into a logical model that can be understood by the client software.
In geographic information systems, a feature is an object that can have a geographic location and other properties. [1] Common types of geometries include points , arcs , and polygons . Carriageways and cadastres are examples of feature data.
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), [a] especially in geographic information systems (GIS). Almost all current relational and object-relational database management systems now have spatial ...
For example, the Esri geodatabase stores vector data ("feature classes") as spaghetti data, but can build a "network dataset" structure of connections on top of a line feature class. The geodatabase can also store a list of topological rules, constraints on topological relationships within and between layers (e.g., counties cannot have gaps ...
A geodatabase can store multiple feature classes or type of features within one file. [72] Geodatabases in ArcGIS can be stored in three different ways – as a "file geodatabase", a "personal geodatabase", or an "enterprise geodatabase" (formerly known as an SDE or ArcSDE geodatabase). [73]
The size of both .shp and .dbf component files cannot exceed 2 GB (or 2 31 bytes) — around 70 million point features at best. [6] The maximum number of feature for other geometry types varies depending on the number of vertices used. The attribute database format for the .dbf component file is based on an older dBase standard.
As with lines, curved boundaries may be allowed; usually a single feature may include multiple polygons, which OGC-SFA collectively terms a surface. Text (alternatively called annotation): a minority of vector data formats, including the Esri geodatabase and Autodesk.dwg, support the storage of text in the
GML defines features distinct from geometry objects. A feature is an application object that represents a physical entity, e.g. a building, a river, or a person. A feature may or may not have geometric aspects. A geometry object defines a location or region instead of a physical entity, and hence is different from a feature.