What is the GDB_GEOMATTR_DATA field used for in an enterprise geodatabase?

In an enterprise geodatabase, most feature classes contain a single spatial column (for example, the SHAPE field) that stores geometry such as points, lines, or polygons. However, depending on the spatial type, some geometries require additional information that cannot always be stored in the single spatial column.

The GDB_GEOMATTR_DATA field is an internal field automatically added by ArcGIS to feature classes that use the following spatial types:

• PostgreSQL PostGIS Geometry or Geography
• SQL Server Geometry or Geography
• SAP Hana ST_Geometry
• Oracle Spatial – The field is named SE_ANNO_CAD_DATA but serves the same purpose

These spatial types store simple geometries represented as points, multipoints, lines, or polygons in a feature class’s shape field. However, geodatabase feature classes must be able to store additional geometric elements used by ArcGIS software, including the following:

• Parametric objects such as circular arcs and Bezier curves created with advanced editing tools
• Multipatch features
• PointIDs
• Surface patches from the ArcGIS Spatial Analyst extension

These additional geometric elements are stored as a blob data type in the GDB_GEOMATTR_DATA field. When a feature is created using additional geometric elements, a simple representation is stored in the shape field, and the additional element is stored in the GDB_GEOMATTR_DATA field.

For example, a polygon created in ArcGIS Pro with the Circle tool is stored in two ways. The GDB_GEOMATTR_DATA field stores the circular feature created with two values – the center and the circle’s radius. The SHAPE field stores a simple feature representation of this circle as a densified arc with many vertices. When this feature is accessed using ArcGIS Pro, the circular feature from the GDB_GEOMATTR_DATA field is used.

Database views and the GDB_GEOMATTR_DATA field

Database views created from geodatabase feature classes use data from the shape field, not from the GDB_GEOMATTR_DATA field, even if it is included in the view’s definition.

The GDB_GEOMATTR_DATA field is a blob type and appears as a user-defined field when viewing the attribute table of the view.

However, when a view is registered with the geodatabase, ArcGIS can access the geometric elements stored in the GDB_GEOMATTR_DATA field.

In the previous example, a circle was stored as a densified polygon in the shape field and as a true circle in the GDB_GEOMATTR_DATA field. A view created from this feature class uses the densified polygon from the SHAPE field. But if the view is registered with the geodatabase, the circle from the GDB_GEOMATTR_DATA field is used.

For multipatch shapes, the SHAPE field contains a simple wireframe or outline of the multipatch shape. The GDB_GEOMATTR_DATA field stores the actual multipatch. If a view is created from this feature class, only the wireframe polygon from the SHAPE column is visible. But if the view includes the GDB_GEOMATTR_DATA field, Multipatch can be chosen for the geometry type when registering the view with the geodatabase, and the full multipatch shape is visible in ArcGIS Pro.