Conceptual Evaluation Strategy
Semantics of an SQL query defined in terms of the following conceptual evaluation strategy:
- Compute the cross-product of relation-list.
- Discard resulting tuples if they fail qualifications.
- Delete attributes that are not in target-list.
- If DISTINCT is specified, eliminate duplicate rows.
This strategy is probably the least efficient way to compute a query! An optimizer will find more efficient strategies to compute the same answers.