Building A Geodatabase _ Xây dựng cơ sở dữ liệu trong GIS

1 The geodatabase supports a model of topologically integrated feature classes, similar to the coverage model. It also extends the coverage model with support for complex networks, relationships among feature classes, and other objectoriented features. The ESRI ® ArcGIS™ applications (ArcMap™, ArcCatalog™, and ArcToolbox™) work with geodatabases as well as with coverages. The ArcInfo geodatabase model is implemented on standard relational databases with the ArcSDE™ application server. ArcSDE defines an open interface to database systems for our users. It allows ArcInfo to manage geographic information on a variety of different database platforms including Oracle®, Microsoft ® SQL Server™, IBM® DB2®, and Informix®. The geodatabase model defines a generic model for geographic information. This generic model can be used to define and work with a wide variety of different user or applicationspecific models. By defining and implementing a wide variety of behavior on a generic geographic model, we provide a robust platform for the definition of a variety of user data models. The geodatabase model supports an objectoriented vector data model. In this model, entities are represented as objects with properties, behavior, and relationships. Support for a variety of different geographic object types is built into the system. These object types include simple objects, geographic features (objects with location), network features (objects with geometric integration with other features), annotation features, and other more specialized feature types. The model allows you to define relationships between objects, together with rules for maintaining the referential integrity between objects.