Database schemas are inevitably going to evolve over time and there's no reason that a fast moving development team should have to worry about these changes potentially leaking sensitive data into lower environments. We've built Tonic to seamlessly handle this by proactively monitoring a source database for schema changes, and then alerting and/or blocking data generation to prevent using an out of date model.
The following scenarios are considered as a schema change by Tonic:
table is missing
column is missing
new table is found
new column found
column nullability changed
column type changed
There are two types of changes flagged by Tonic:
Action Required : When the schema change involves an object (table or column) that is included in one of the models in Tonic, it has to be resolved  before you can generate data
Notifications : When a new table or field has been added, this is classified as a notification that will remain visible until dismissed.
When the schema changes tool detects a change in the source database that requires a user action, it surfaces a warning flag  on the sidebar and blocks data generation .
If desired, data generations may be blocked when any schema change is detected, regardless of whether the underlying change is classified as Action Required or Notification. To enable this optional schema strictness check, activate the strictness toggle found in Edit Workspace -> Generation Details .