Comparing geodatabases

When you are evaluating the changes that have been made to a data model, you may want to compare it with the existing version to see the differences. For example, you may want to see how many fields have been added to the new schema to determine whether or not an update is necessary.

The Data Comparison tool allows you to compare an existing database to an updated version of the data model. Using this tool, you can track the differences between various aspects of the database including the schema, geometry, attributes, and spatial reference. You can also choose to compare the databases based on all these aspects or a specific one. The particular items that are compared for each comparison type are displayed in the table below.

Comparison type	What is compared
ALL	Extension class IDs Feature class extents Feature class feature types Feature class shape types Field existence Field length Field type Field var type Subtype default value Table or feature class existence Table row counts XY precision
ATTRIBUTES_ONLY	Feature class field values Number of table fields Number of table rows Subtype default values Subtype names
GEOMETRY_ONLY	M tolerance Table or feature class existence Z precision Z tolerance
SCHEMA_ONLY	Field types Field lengths Field var types Geometry definition M-values Number of table fields Table or feature class existence Table fields Z-values
SPATIAL_REFERENCE_ONLY	M tolerance XY precision Z precision Z tolerance

Database items compared

步骤:

1. Start ArcCatalog.
2. On the main menu, click Customize > Toolbars > Defense Mapping.
3. On the Defense Mapping toolbar, click Defense Mapping > Data Comparison.

   The Data Comparison dialog box appears.

4. Click the ellipsis (...) next to the Select Template Geodatabase text box.

   The Select base geodatabase as template dialog box appears.

5. Navigate to the database that contains the version of the schema you want to compare.
6. Click Select.

   The Data Comparison dialog box appears.

7. Click the ellipsis (...) next to the Select Geodatabase to Compare text box.

   The Select test geodatabase to compare dialog box appears.

8. Navigate to the geodatabase whose schema you want to compare.
9. Click Select.

   The Data Comparison dialog box appears.

10. Click the ellipsis (...) next to the Select Location For Compare Report text box.

    The Save As dialog box appears.

11. Navigate to the directory in which you want to save the comparison report.
12. Type a name for the file in the File name text box.
13. Click Save.

    The Data Comparison dialog box appears.

14. To change the types of items compared between the two databases, click the Compare Type drop-down arrow and choose a different option.

    By default, all aspects of the database are compared.

15. To ignore all m-related information in the databases, check the IGNORE M check box.
16. To ignore all z-related information in the databases, check the IGNORE Z check box.
17. To ignore all point ID attributes in the databases, check the IGNORE POINTID check box.
18. To ignore all extension property attributes in the databases, check the IGNORE EXTENSION PROPERTIES check box.
19. To stop database comparison when a difference is found, uncheck the Continue comparison check box.

    By default, the check box is checked.

20. To only report differences between the two databases, check the Report only errors check box.

    By default, the check box is not checked.

21. Click Apply.

    Once the comparison process is complete, the Data Comparison report generated dialog box appears.

22. Click Yes to view the results.

The report appears in a text editor such as Notepad.