Desktop Help 10.0 - Network datasets in a geodatabase in Informix

Network datasets are collections of feature classes that possess a connectivity relationship. Network datasets are created using three types of sources—edge feature sources, such as street centerlines; junction feature sources, such as point feature classes containing railroad crossings; and turn feature sources. They are used to model transportation. To use network datasets, you must have the ArcGIS Network Analyst extension installed.

Network datasets in ArcGIS Desktop

In the Catalog tree, feature datasets that contain network datasets in Informix look the same until you expand the dataset. Once the dataset is expanded, you see the network dataset, which is represented by the following icon:

Network dataset icon

The name of the network in a geodatabase in Informix contains the name database name followed by a colon (:), the name of the network owner, and the name of the network itself.

For example, a network dataset, canals_nd, owned by gdb in the geodatabase sdedb would be listed in the Catalog tree as sdedb:gdb.canals_nd.

When you create a network dataset, a system junctions feature class is also created. This feature class has the name of the network dataset followed by _Junctions.

Network datasets in an IBM Informix database

Network datasets are tracked in the gdb_items table. The gdb_itemtypes table stores a value indicating that the object is a network dataset. The gdb_itemrelationships table stores information on how the network and the feature dataset it is in are related.

There are also tables that are created in the schema of the user who owns the network dataset. They are as follows:

n_<id>_desc: The n_<id>_desc table describes the elements of a network. This is a normalized table whose row count is equal to the number of junctions, edges, and turns in a geometric network.
n_<id>_props: The n_<id>_props table contains a summary description of a network's properties, such as element counts and maximum EID values.
n_<id>_topology: This table stores all topology BLOB pages.
n_<id>_edgeweight: This table stores all BLOB pages for edge weight values.
n_<id>_junctionweight: This table stores all BLOB pages for junction weight values.
n_<id>_turnweight: This table stores all BLOB pages for turn weight values.
nd_<itemid>_dirtyareas: The nd_<itemid>_dirtyareas table stores information about spatial features in the network that have been edited.
nd_<itemid>_dirtyobjects: The nd_<itemid>_dirtyobjects table stores information about edited relational objects in the network dataset.

The ID in the names of the first six tables is the logicial network ID. The itemID in the last two tables is the objectid from the gdb_items table.

The structures for the tables are as follows:

n_<id>_desc

The n_<id>_desc table describes the elements of a network. This is a normalized table whose row count is equal to the number of junctions and the number of edges in a geometric network.

Field name	Field type	Description	Null?
oid	integer	The unique identifier of an element in a network	NOT NULL
userclassid	integer	The identifier of the feature class to which the element belongs	NOT NULL
userid	integer	The ObjectID of the feature	NOT NULL
usersubid	integer	The identifier of an element in a feature; only applicable to complex edge features	NOT NULL
elementtype	smallint	A code indicating the type of network element	NOT NULL
eid	integer	The unique element identifier of the network element; only unique for the type of network element	NOT NULL

n_<id>_props

The n_<id>_props table contains a summary description of a network's properties, such as element counts and maximum EID values.

Field name	Field type	Description	Null?
propertyid	integer	The unique identifier of the network property	NOT NULL
propertyname	varchar(32)	The name of the property	NOT NULL
propertyvalue	integer	The value of the property	NOT NULL

nd_<itemID>_dirtyareas

The nd_<itemid>_dirtyareas table tracks what spatial features in the network dataset have been edited.

Field name	Field type	Description	Null?
objectid	integer	Unique identifier for the record	NOT NULL
isretired	integer	Indicates whether this feature is still used to track the dirty area of a network dataset	NOT NULL
dirtyarea	st_geometry	The polygon geometry of the dirty area

nd_<itemID>_dirtyobjects

The nd_<itemid>_dirtyobjects table tracks edited relational objects in the network dataset such as turns and historical traffic records.

Field name	Field type	Description	Null?
objectid	integer	Unique identifier for the record	NOT NULL
classid	integer	The objectID of the dirty object item in the gdb_items table	NOT NULL
oid	integer	The object ID of the dirty object	NOT NULL
updatetype	smallint	The type of edit performed—insert (0), update (1), or delete (2)—that resulted in the dirty object	NOT NULL

All of the remaining network tables contain the same field names and types. Their structure is as follows:

Field name	Field type	Description	Null?
oid	integer	The unique identifier of the BLOB page in the table	NOT NULL
pagenumber	integer	The number of the BLOB page in the table	NOT NULL
pageblob	BLOB	The actual BLOB page, which contains a description for the element the table is describing, such as edge and edge status
tableid	integer	For the n_<ID>_edgeweight, n_<ID>_turnweight, and n_<ID>_junctionweight BLOB tables, the tableID is the weightID. For the n_<ID>_topology BLOB table, the tableID is the position of the original table within the array of topology tables defined in the GeoDatabase\GeoDatabase\Network\Network\TableDefs.h file.	NOT NULL

The following is a diagram of a network dataset in Informix:

Network dataset tables in Informix

Dashed lines indicate implicit relationships between columns.

There are additional, optional tables you may use as part of your network dataset to model travel times based on historical traffic speeds or denote changes in time zone that could affect network analysis. These are tables that you create prior to creating your network dataset and are stored in your schema (just like the feature class on which a network is built is in the creator's schema). You specify the names of the tables. See the Network Analyst section of the documentation for details on using these historical traffic and time zone tables.

Network datasets in an XML workspace document

The following is an excerpt from an XML document created by exporting from a network dataset. The edge and junction elements' properties are listed below:

<EdgeFeatureSources xsi:type="esri:ArrayOfEdgeFeatureSource">
  <EdgeFeatureSource xsi:type="esri:EdgeFeatureSource">
    <ID>1</ID> 
    <ClassID>99</ClassID> 
    <Name>sdedb:gdb.canals</Name> 
    <ElementType>esriNETEdge</ElementType> 
    <Properties xsi:nil="true" /> 
    <FromElevationFieldName /> 
    <ToElevationFieldName /> 
    <Connectivity xsi:type="esri:PropertySet">
      <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
        <PropertySetProperty xsi:type="esri:PropertySetProperty">
          <Key>Version</Key> 
          <Value xsi:type="xs:short">1</Value> 
        </PropertySetProperty>
        <PropertySetProperty xsi:type="esri:PropertySetProperty">
          <Key>UsesSubtypes</Key> 
          <Value xsi:type="xs:short">0</Value> 
        </PropertySetProperty>
        <PropertySetProperty xsi:type="esri:PropertySetProperty">
          <Key>ClassConnectivity</Key> 
          <Value xsi:type="xs:short">1</Value> 
        </PropertySetProperty>
        <PropertySetProperty xsi:type="esri:PropertySetProperty">
          <Key>SubtypeConnCount</Key> 
          <Value xsi:type="xs:int">0</Value> 
        </PropertySetProperty>
        <PropertySetProperty xsi:type="esri:PropertySetProperty">
          <Key>DefaultGroup</Key> 
          <Value xsi:type="xs:int">1</Value> 
        </PropertySetProperty>
        <PropertySetProperty xsi:type="esri:PropertySetProperty">
          <Key>GroupCount</Key> 
          <Value xsi:type="xs:int">0</Value> 
        </PropertySetProperty>
      </PropertyArray>
    </Connectivity>
   </EdgeFeatureSource>
 </EdgeFeatureSources>
 <JunctionFeatureSources xsi:type="esri:ArrayOfJunctionFeatureSource" /> 
 <SystemJunctionSources xsi:type="esri:ArrayOfSystemJunctionSource">
   <SystemJunctionSource xsi:type="esri:SystemJunctionSource">
     <ID>2</ID> 
     <ClassID>1683</ClassID> 
     <Name>sdedb:gdb.canals_nd_Junctions</Name> 
     <ElementType>esriNETJunction</ElementType> 
     <Properties xsi:nil="true" /> 
     <ElevationFieldName /> 
   </SystemJunctionSource>
 </SystemJunctionSources>
 <TurnFeatureSources xsi:type="esri:ArrayOfTurnFeatureSource" /> 
   <EvaluatedNetworkAttributes xsi:type="esri:ArrayOfEvaluatedNetworkAttribute">
     <EvaluatedNetworkAttribute xsi:type="esri:EvaluatedNetworkAttribute">
       <ID>1</ID> 
       <Name>speed</Name> 
       <Units>Unknown</Units> 
       <DataType>esriNADTBoolean</DataType> 
       <UsageType>esriNAUTRestriction</UsageType> 
       <UserData xsi:nil="true" /> 
       <UseByDefault>true</UseByDefault> 
       <AttributeParameters xsi:type="esri:ArrayOfNetworkAttributeParameter" /> 
     </EvaluatedNetworkAttribute>
     <EvaluatedNetworkAttribute xsi:type="esri:EvaluatedNetworkAttribute">
       <ID>2</ID> 
       <Name>oneway</Name> 
       <Units>Unknown</Units> 
       <DataType>esriNADTBoolean</DataType> 
       <UsageType>esriNAUTRestriction</UsageType> 
       <UserData xsi:nil="true" /> 
       <UseByDefault>true</UseByDefault> 
       <AttributeParameters xsi:type="esri:ArrayOfNetworkAttributeParameter" /> 
     </EvaluatedNetworkAttribute>
     <EvaluatedNetworkAttribute xsi:type="esri:EvaluatedNetworkAttribute">
       <ID>3</ID> 
       <Name>timeofday</Name> 
       <Units>Unknown</Units> 
       <DataType>esriNADTInteger</DataType> 
       <UsageType>esriNAUTCost</UsageType> 
       <UserData xsi:nil="true" /> 
       <UseByDefault>true</UseByDefault> 
       <AttributeParameters xsi:type="esri:ArrayOfNetworkAttributeParameter" /> 
     </EvaluatedNetworkAttribute>
   </EvaluatedNetworkAttributes>
   <NetworkAssignments xsi:type="esri:ArrayOfNetworkAssignment">
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>speed</NetworkAttributeName> 
       <NetworkElementType>esriNETJunction</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:boolean">false</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>speed</NetworkAttributeName> 
       <NetworkElementType>esriNETEdge</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:boolean">false</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>speed</NetworkAttributeName> 
       <NetworkElementType>esriNETTurn</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:boolean">false</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>oneway</NetworkAttributeName> 
       <NetworkElementType>esriNETJunction</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:boolean">false</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>oneway</NetworkAttributeName> 
       <NetworkElementType>esriNETEdge</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:boolean">false</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>oneway</NetworkAttributeName> 
       <NetworkElementType>esriNETTurn</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:boolean">false</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>timeofday</NetworkAttributeName> 
       <NetworkElementType>esriNETJunction</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:int">0</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>timeofday</NetworkAttributeName> 
       <NetworkElementType>esriNETEdge</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:int">0</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
     <NetworkAssignment xsi:type="esri:NetworkAssignment">
       <IsDefault>true</IsDefault> 
       <ID>-1</ID> 
       <NetworkAttributeName>timeofday</NetworkAttributeName> 
       <NetworkElementType>esriNETTurn</NetworkElementType> 
       <NetworkEvaluatorCLSID>{318C4B91-F5D2-467A-996C-0AB51B0D8FF2}</NetworkEvaluatorCLSID> 
       <NetworkEdgeDirection>esriNEDNone</NetworkEdgeDirection> 
       <NetworkEvaluatorData xsi:type="esri:PropertySet">
         <PropertyArray xsi:type="esri:ArrayOfPropertySetProperty">
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>Version</Key> 
             <Value xsi:type="xs:short">1</Value> 
           </PropertySetProperty>
           <PropertySetProperty xsi:type="esri:PropertySetProperty">
             <Key>ConstantValue</Key> 
             <Value xsi:type="xs:int">0</Value> 
           </PropertySetProperty>
         </PropertyArray>
       </NetworkEvaluatorData>
     </NetworkAssignment>
   </NetworkAssignments>
 <ConfigurationKeyword>NETWORK_DEFAULTS</ConfigurationKeyword>

Network datasets in a geodatabase in Informix

Network datasets in ArcGIS Desktop

Network datasets in an IBM Informix database

Network datasets in an XML workspace document

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