- Widen the Data Model:
Legacy Data Model: Product (id, name, description)
New Data Model: Product (id, name, description, price, category, manufacturer)
In this phase, the data model is widened by adding new fields such as price, category, and manufacturer to accommodate additional product information.
- Migrate Existing Data
Data from the legacy system is migrated to the new data model. For each product record, values are mapped to the corresponding fields in the expanded schema. For example, existing product descriptions are mapped to the description field, and so on.
- Gradually Narrow the Model
After successful migration, the data model is refined. Unused fields or redundant structures introduced during the widening phase may be removed. For instance, if certain product attributes are found to be rarely used, they can be eliminated from the schema to streamline data management.