Oracle is a database management system produced by the Oracle Corporation.
Geodatabases stored in an Oracle DBMS have system tables, which are created and maintained in the schema of the ArcSDE administrator. These system tables maintain information about and manage the data in the geodatabase.
Geodatabases stored in Oracle also contain user-defined datasets such as feature classes and raster catalogs. These tables store the spatial and attribute information of your GIS data. They are stored in the schema of the user who creates them. User-defined datasets should not be stored in the ArcSDE administrator's schema; therefore, you should use another user name to connect to the geodatabase when you are creating datasets.
Feature classes stored in a geodatabase in Oracle can be stored using four different geometry storage types: ArcSDE Compressed Binary, OGC well-known binary, an ISO and OGC compliant SQL access data type (ST_Geometry), or Oracle Spatial (SDO_Geometry).
Raster data stored in a geodatabase in Oracle can be stored using either binary LONG RAW storage, binary BLOB storage, or Oracle GeoRaster.
For a comparison and explanation of each of these storage types, see the topics in the book "Feature geometry and raster storage types." To start, see An overview of feature geometry and raster data storage.
The following topics describe both the user-defined and system tables found in a geodatabase in Oracle.
