After you make changes to a model, you might want to compare the
model to an earlier version of a model. Or, you might want to compare models
of two different databases and move the differences between the models.
When you compare two models, you can easily see and navigate through the
differences between the models. Comparing a changed model to an earlier version
of the model lets you:
- Check your work and verify the changes are what you intended
- Use the information as an auditing tool to understand the differences
between the two model versions
You can also use model comparison when you want to migrate the changes
from one database environment to another. Comparing the model of the source
database to the model of the target database lets you:
- Analyze the differences between the two models
- Move the changes from the source database model to the target database
model
Model comparison can also be important when you are about to deploy your
change commands to the database and you check to ensure that the current database
catalog and base model still match. If the current database has changed and
you refresh the base model to reflect the changes, you should compare the
base and target models again to verify your planned changes. After you verify
the changes, you can regenerate the change commands.