Pitney Bowes MapXtreme - Manual (Page 218)

Chapter 11: Accessing Data from a DBMS
Accessing Data from Oracle
MapXtreme v7.1 225 Developer Guide
those dimensions are ignored during insert/update operations. For geometries not containing
dimensions supported by the Oracle table, NULL values are supplied for the missing dimensions
during insert/update operations. For example, when inserting a geometry with no Z or M values into
a table that is defined with dimensions x, y, and m, the M values stored in the table will be NULL.
The success of any of these insert/update operations may also be dependent upon additional
server-side validation including explicit column constraints and validation of values against the
dimensional extents specified in the SDO_GEOM_METADATA system table.
SDO_GEOMETRY Arc and Circle Translation
Circles and circular arcs can be resolved to MultiCurves with a resolution of 25 segments per 360
degree circle.
Visualization of Non-translatable Oracle Objects
An Oracle Spatial Object that your MapXtreme application is unable to translate produces a Point
object with a default style (a black star) at the location of the SDO_Spatial point, or the first
SDO_Spatial ordinate in the ordinate array. This is to enable a visual representation of the non-
translatable object in the proper geographic area to which it belongs. Examples of non-translatable
objects are user-defined objects GTypes 0,4,5, or invalid SDO_geometries containing unrecognized
GTypes, ETypes, or interpretations. The second class should also fail using
SDO_VALIDATE_GEOMETRY().
Centroid Support
A MapXtreme application uses the SDO_POINT as the centroid value for polygons. This centroid
feature is used to position labels, and also affects the tool selection of the object. The Oracle
SDO_GEOMETRY.SDO_POINT_TYPE field (if not NULL) is interpreted as the feature centroid if the
point exists inside the region. If the point exists outside of the region, its centroid is calculated as
always.
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There is currently no method or tool in MapXtreme to set the centroid of a region feature, but
one may read and use a stored centroid.
Oracle Spatial Reference Support (SRID)
An Oracle SDO_GEOMETRY column may be defined with a spatial referencing system. This is
done by providing the Oracle SRID in the USER_SDO_GEOM_METADATA and also by assigning
that SRID in the stored SDO_GEOMETRY values. If a table contains an Oracle Spatial column with
an assigned SRID, your MapXtreme application is able to query and properly interpret the data. The
MapInfo_MapCatalog must contain the same MapInfo Professional CoordSys string as indicated in
the SRID of the data, since it is the Coordsys in the MapInfo_MapCatalog that is currently used to
interpret and update the data.