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Archiving scenarios

Archiving scenarios
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Geodatabase archiving allows you to analyze your data as it changes over time. The archive class and the Geodatabase History Viewer can act as useful problem-solving tools. The following are some hypothetical scenarios where geodatabase archiving can be used:

A fire marshal mapping a forest fire can implement geodatabase archiving to help monitor the spreading flames. By creating edits based on the fire's perimeter and saving these edits continually in 20-minute intervals, the marshal can build an archive of the fire boundary over time. He may then use the geodatabase history viewer to switch to important moments in the fire's history. For example, if the wind picks up and the fire's intensity increases and becomes unpredictable, the marshal can switch to a time prior to this event and view how the fire was situated before. This may help determine where to allocate resources in an attempt to contain the spreading.

If the same fire marshal wanted to see how the fire has spread over time, he could add the fire perimeter archive class to the map. As the fire's boundary changes with the fire spreading, its perimeter is edited and updated in the archive class every 20 minutes. By color-coding the fire's perimeter based on the gdb_to_date field, the marshal can view every instance of the perimeter over time. The resulting map will show a different-colored ring every 20 minutes, the expanding boundary of the fire.

A similar example is helpful in parcel management. As edits are made to parcels over time, they can be kept in the archive class. If you want to view how the parcels looked at a certain moment for taxation purposes, for example, you could use the geodatabase history viewer to switch to the appropriate date and time. If instead you wanted to see how a certain parcel has changed over time, you could add the parcel archive class to the map and select the appropriate parcel by its ID number. This would show every representation of the selected parcel through time.

Archiving example

The following example uses a dataset containing building polygons to describe the ArcGIS archiving functionality.

The building dataset consists of three buildings:

Buildings polygons

These buildings have had several edits applied to them. After each edit was made, it was saved to default. The Archive class therefore has kept a record of each edit made to the buildings feature class. After each edit was made, a historical marker was created in the Historical Marker Manager. This makes it easy to connect to the historical version for the moment of each particular edit.

Learn more about working with historical markers.

The following graphic shows the Historical Marker Manager being opened from the Geodatabase History toolbar. The manager displays the historical markers that were made:

Historical marker manager

By changing to a historical version of the buildings feature class, the Geodatabase History Viewer becomes enabled.

Learn more about working with a historical version.

The following graphic shows the Change Version button on the Versioning toolbar being pressed to open the Change Version dialog box. The 1 - Building start historical marker is used to change to a historical version:

Changing to a historical version

Now that the Geodatabase History Viewer is enabled, it is easy to switch between the historical markers designated for each edit and view the representation of the buildings throughout their history.

Learn more about working with the Geodatabase History Viewer.

The following graphic depicts the Geodatabase History Viewer button on the Geodatabase History toolbar being clicked to open the Geodatabase History Viewer. The 4 - Move building 1 historical marker is used to change the map view to reflect the historical version particular to that historical date and time:

USing the geodatabase history viewer

Switching to the 4 - Move Building 1 historical marker shows the moment in time when the edit was made to move the location of building 1:

Moving building 1

Historical marker 5 - Split building 2 shows the moment when building 2 was split into buildings 2 and 4:

Splitting building 2

By switching through historical markers 6, 7, and 8, you can see how building 3 is modified and then deleted over time:

Modifying building 3

The historical markers 9, 10, and 11 display the moments in time showing edits to create building 5 and then add an extension to it:

Creating and deleting building 5

You can also add the buildings archive class to the map in order to view all the representations of the buildings throughout their history.

Learn more about working directly with the archive class.

The following graphic shows how symbolizing the map with the values from the GDB_FROM_DATE field can color code the archive class based on the moment in time when updates were saved to default. This displays the various representations of each of the buildings throughout the history of the dataset. Building 4, being the last building updated, is color coded for the most recent date and time:

Adding the buiildings archive class to the map

See Also

  • Geodatabase archiving
  • Enabling archiving
  • The archive process
  • Working with a historical version
  • Working with historical markers
  • Working directly with the archive class