The datasets in your ArcSDE geodatabase can be registered as versioned without the option to move edits to base, registered as versioned with the option to move edits to base, or not registered as versioned. By default, when you add or create a dataset in an ArcSDE geodatabase, the data is not registered as versioned. For an introduction to these options, see Data maintenance strategies
NOTE: Only the owner of the data may register or unregister it as versioned.
Registering your data as versioned without the option to move edits to base allows you to take advantage of all versioned editing functionality. This includes the following:
- Undo and redo edits.
- Perform long transaction edits.
- Use named versions for designs and projects.
- Use geodatabase archiving.
- Use replication.
- Place a unique constraint on the base table of a feature class.
NOTE: If, when you compress the database, the changes written to the base table from the delta tables invalidate the constraint, the compress will fail and you will have to either remove the constraint or figure out which row made the constraint invalid and fix the error.
However, before you register data, consider that there are certain ArcGIS operations you can't perform on data that is registered as versioned. These operations are as follows:
- Create a topology.
- Add or remove feature classes from a topology.
- Add or remove topology rules.
- Modify the cluster tolerance or ranks.
- Create a geometric network.
- Add or remove a feature class from a geometric network.
Additionally, when importing a large amount of data, performance is better if you import to a feature class or table that hasn't been registered as versioned.
If you decide to register a feature dataset, stand-alone feature class, or table as versioned, right-click on it in the ArcCatalog tree and click Register As Versioned. This will open the Register As Versioned dialog box. Leave the move edits to base option unchecked, and click OK. When you leave this option unchecked, edits to all versions, including the DEFAULT, are preserved in the delta tables.
Note to the database administrator:
Registering a dataset creates the supporting delta tables—the adds (A) and deletes (D) tables—as well as attribute indexes. The A and D tables and their attribute indexes have the potential to be among the most active in your geodatabase. In this case, these tables are read during all queries against the feature class or table. Also, any time a user makes an edit, a row is added to one or both of these tables, so these tables will grow quickly in an actively edited geodatabase. For this reason, you need to plan for their storage and periodic compression to maintain good performance. For recommendations on storage, see Recommendations to minimize disk I/O contention
. To learn more about performing a geodatabase compress, see Compressing the database
and About compressing a geodatabase
Registering data as versioned with the option to move edits to base allows you to perform versioned edits on the data. Although registering data this way is designed to support nonversioned edits by third-party applications, you can't perform nonversioned edits through ArcGIS.
Keep in mind that in addition to the ArcGIS operations you can't perform when the data is registered as versioned (as described above), if you register as versioned and specify the option to move edits to base, you cannot do the following:
- Edit feature classes that participate in a topology or geometric network.
- Archive data with the archiving functionality built into the geodatabase.
- Make use of geodatabase replication.
If you decide to register a feature dataset, stand-alone feature class, or table as versioned with the option to move edits to base, right-click on it in the ArcCatalog tree and click Register As Versioned to open the Registration dialog box. Check Register the selected objects with the option to move edits to base. Checking this option causes edits saved to the DEFAULT version, whether edited directly or merged in from other versions, to be saved in the business tables. Edits to other versions remain in the delta tables when you save.
This option is available for simple features only—those that do not participate in a topology or geometric network. Therefore, if you open the Register As Versioned dialog box and find the move edits to base tables check box is not active, it means your dataset contains a topology or geometric network.
As mentioned above, your data is initially not registered as versioned. If it remains in this state, you can perform nonversioned edits and you can create or modify a topology and create or modify a geometric network.
If you've already registered a feature class as versioned and need to perform one of the above operations, you will need to unregister the feature class as versioned. When you unregister a feature class, the delta tables are dropped from the database—that means all versioned edits that were made but not posted will be lost
. To prevent these edits from being lost, either compress all the edits to the base table before unregistering the data or compress them to the DEFAULT version from the Unregister As Versioned dialog box. The software will prompt you to compress the edits to the base table when you attempt to unregister a feature class as versioned.
By default, the Unregister As Versioned command is not present on the dataset context menu.
To avoid the need to unregister feature classes, try to apply all topology and geometric network behavior to your geodatabase before you register data. Pilot the topology and geometric network in a personal geodatabase or on a production server to ensure that you are not missing any rules. This can save you from having to unregister feature classes later in production.