E-Book Overview
CA Technologies, 2011. — 98 p. (Автор не указан).
Contents: Introduction. Data Modeling Concepts. Benefits of Data Modeling. Methods. Typographical Conventions. Information Systems, Databases, and Models. Introduction. Data Modeling. Data Modeling Sessions. Session Roles. Sample IDEF1X Modeling Methodology. Modeling Architecture. Logical Models. Entity Relationship Diagram. Key-Based Model. Fully-Attributed Model. Physical Models. Transformation Model. DBMS Model. Logical Models. How to Construct a Logical Model. Entity Relationship Diagram. Entities and Attributes Defined. Logical Relationships. Many-to-Many Relationships. Logical Model Design Validation. Data Model Example. The Key-Based Data Model. Key-Based Data Model. Key Types. Entity and Non-Key Areas. Primary Key Selection. Alternate Key Attributes. Inversion Entry Attributes. Relationships and Foreign Key Attributes. Dependent and Independent Entities. Identifying Relationships. Non-Identifying Relationships. Rolenames. Naming and Defining Entities and Attributes. Overview. Entity and Attribute Names. Synonyms, Homonyms, and Aliases. Entity Definitions. Descriptions. Definition References and Circularity. Business Glossary Construction. Attribute Definitions. Validation Rules. Rolenames. Definitions and Business Rules. Model Relationships. Relationships. Relationship Cardinality. Cardinality in Non-Identifying Relationships. Referential Integrity. Referential Integrity Options. RI, Cardinality, and Identifying Relationships. RI, Cardinality, and Non-Identifying Relationships. Additional Relationship Types. Many-to-Many Relationships. N-ary Relationships. Recursive Relationships. Subtype Relationships. Complete Compared to Incomplete Subtype Structures. Inclusive and Exclusive Relationships. IDEF1X and IE Subtype Notation. When to Create a Subtype Relationship. Normalization Problems and Solutions. Normalization. Overview of the Normal Forms. Common Design Problems. Repeating Data Groups. Multiple Use of the Same Attribute. Multiple Occurrences of the Same Fact. Conflicting Facts. Derived Attributes. Missing Information. Unification. How Much Normalization Is Enough. Support for Normalization. First Normal Form Support. Second and Third Normal Form Support. Physical Models. Objective. Support for the Roles of the Physical Model. Summary of Logical and Physical Model Components. Denormalization. Appendix A: Dependent Entity Types. Classification of Dependent Entities. Glossary. Index.
E-Book Content
CA ERwin® Data Modeler
Methods Guide r8
This documentation, which includes embedded help systems and electronically distributed materials, (hereinafter referred to as the “Documentation”) is for your informational purposes only and is subject to change or withdrawal by CA at any time. This Documentation may not be copied, transferred, reproduced, disclosed, modified or duplicated, in whole or in part, without the prior written consent of CA. This Documentation is confidential and proprietary information of CA and may not be disclosed by you or used for any purpose other than as may be permitted in (i) a separate agreement between you and CA governing your use of the CA software to which the Documentation relates; or (ii) a separate confidentiality agreement between you and CA. Notwithstanding the foregoing, if you are a licensed user of the software product(s) addressed in the Documentation, you may print or otherwise make available a reasonable number of copies of the Documentation for internal use by you and your employees in connection with that software, prov