A suitable database schema for a test suite satisfies four criteria.
- The schema should be natural. That is, it should correspond to
a reasonable, though possibly greatly simplified, segment of the
real world. This both reduces the need to explain the model and
enhances the ability to recognize verball pitfalls in the path to
the query instances.
- The schema should be simple. This will aid in making the test
suite easy to understand. This criterion indicates that a database
schema consisting of relatively few relation schemas, with
relatively few attributes, is desirable. Additionally, the names of
the relations and of the attributes should be short, as they will be
referenced repeatedly.
When an expansion is proposed, the benefits should be carefully
compared with the added complexity.
- The schema should allow for comprehensiveness within the
chosen scope. Using the schema, it should be possible formulate
queries of all the types that appear reasonable.
This indicates a need for at least two related relation schemas (for
natural-join queries).
- A schema that has already been used frequently is preferred
over a new schema. This guarantees that many existing queries can be
adapted easily to the test suite.
- For clarity, schema and attribute names must start with
capital letters.