O V E R V I E W

GeoData Services

A geodata service represents a connection to a geodatabase and is designed for distributed data management.
 

Use a geodata service to:

• List datasets, versions, and replicas

• Execute tabular and feature queries

• Extract and download data

• Checkout data for subsequent editing and check-in

• Create replicas that support periodic synchronization
   

WSDL syntax

http://<Web Server Hostname>/<ArcGIS Instance>/services/<ServiceName>/GeoDataServer?wsdl

Working with geodata services

Extracting and querying data are relatively straightforward.  Data extraction involves copying a portion of some data in a geodatabase while query functionality includes the ability to return rows from a table based on a query filter.  Replication can be more complicated.  Geodatabase replication is the process of distributing data across two or more geodatabases so that they can periodically synchronize changes. Replication includes checkout/check-in replication, two-way replication, and one-way replication. To create applications using this functionality, a developer should understand geodatabase replication concepts.

   
Check out/Check in Replication
 

Check out/check in replication allows you to edit the child replica's data and then synchronize these edits with the parent replica. Once the data has been synchronized you can no longer synchronize additional edits. If additional edits are required, you must create a new check-out replica.

When creating check-out replicas, the destination can be either an ArcSDE, file or personal geodatabase.

The check-out replicas are designed to be edited in an ArcGIS desktop application, such as ArcMap.

One Way Replication
 

One way replication allows data changes to be sent multiple times from the parent replica to the child replica. Changes cannot be sent from the child replica to the parent replica.  Here the parent replica's data is editable, but the data on the child is considered read-only. If edits are performed on the child replica's data, they will be over-written if they conflict with edits applied during synchronization. Conflicts are not reported when synchronizing with one way replicas. One way replicas continue to exist after synchronization, allowing you to continue sending data changes from the parent replica to the child replica. When creating one way replicas, the destination may be an ArcSDE geodatabase, a file geodatabase or a personal geodatabase.
 

One way replicas can use either a full or a simple model type:

Full - The full model supports complex types (topologies and geometric networks) and requires the child replica's data to be versioned.

Simple - With a simple model, the child replica's data is created as simple types and is not registered as versioned. Therefore, geometric networks or topologies from the source geodatabase are not created on the destination geodatabase.

Two Way Replication
 

Two way replication allows data changes to be sent multiple times from the parent replica to the child replica or from the child replica to the parent replica. If the same row is edited in both replica geodatabases, it is detected as a conflict when the replicas are synchronized. Reconcile policies are provided to define how conflicts are processed. Two way replicas continue to exist after synchronization allowing you to continue editing and synchronizing the replicas.

 

Methods