Relational database design consists of three consecutive phases. designER fully covers the first two and prepares the model for the third.
| Phase | Input → output | In designER |
|---|---|---|
| Conceptual design | Requirements in natural language → ER schema | Step 1: schema creation on the canvas |
| Logical design | ER schema → relations with keys and referential constraints | Step 2: restructuring Step 3: translation |
| Physical design | Logical schema → DBMS-specific structures and SQL | Step 4: DBMS-independent part (data types, column order, SQL generation) |
Logical design follows well-defined rules, but it is not entirely automated. Several constructs can be translated in multiple ways, with the optimal choice depending on the specific application. designER applies these underlying rules while leaving design decisions in the hands of the designer.