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Rule-based engineering

Rule-based engineering the target specification is produced following a set of translation rules . Transformation-based engineering the target specification is produced by application of a chain of substitution operators to the source specifications. 1. Introduction.

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Rule-based engineering

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  1. Rule-based engineering the target specification is produced following a set of translation rules. Transformation-based engineering the target specification is produced by application of a chain of substitution operators to the source specifications. 1. Introduction Rule-basedvsTransformation-based engineering

  2. Rule-based viewof Database Engineering Example: producing a relational schema from a conceptual schema 1. Introduction  Physical schema (MS Access) Conceptual schema (ER)

  3. Rule-based viewof Database Engineering Natural procedure: through translation rules 1. Introduction

  4. Rule-based viewof Database Engineering 1. Introduction • OK, but what if: •  attribute A is at level 2, 3, …? •  attribute A is not atomic? •  relationship type R is many-to-many, or one-to-one, or N-ary? •  the primary key of E has not been translated yet (e.g., it comprises a FK still untranslated)? •  Combinatorial explosion and complexity of the set of rules.

  5. Transformation-based viewof Database Engineering Transforming the multivalued attribute Author 1. Introduction 

  6. Transformation-based viewof Database Engineering Transforming the many-to-many relationship type write 1. Introduction 

  7. Transformation-based viewof Database Engineering Transforming the one-to-many relationship type aw (and the others) 1. Introduction 

  8. Transformation-based viewof Database Engineering Coding (generally simple; rule-based or transformational) 1. Introduction  No more than 5 WRITE rows per BOOK row.

  9. 1. Introduction • Transformation-based viewof Database Engineering • What if the attribute is multivalued, compound and comprises other multivalued components ? rule? 

  10. Transformation-based viewof Database Engineering 1. Introduction  Note: slightly different variant of the transformation of an attribute into an entity type

  11. Transformation-based viewof Database Engineering 1. Introduction  

  12. Transformation-based viewof Database Engineering 1. Introduction   

  13. Transformation-based viewof Database Engineering Observations no new operators iterative application of known operators compositional property of transformations (the composition of two transformations still is a transformation) no combinatorial explosion, just the right (small) set of operators need for meta-rules for applying the operators (a transformation plan) 1. Introduction

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