TAILIEUCHUNG - Lecture Database Systems - Lecture 29

After completing this chapter, students will be able to: Basic concepts, tree-structure diagrams, data-retrieval facility, update facility, virtual records, mapping of hierarchies to files, the IMS database system. | CSC271 Database Systems Lecture # 29 Summary: Previous Lecture The normalization process 1NF, 2NF, 3NF Inference rules for FDs BCNF Summary: Normalization First normal form (1NF) A relation in which the intersection of each row and column contains one and only one value Second normal form (2NF) A relation that is in 1NF and every non-PK attribute is fully functionally dependent on the primary key (CKs) Third normal form (3NF) A relation that is in 1NF and 2NF and in which no non-primary-key attribute is transitively dependent on the primary key (CKs) Boyce–Codd normal form (BCNF) A relation is in BCNF if and only if every determinant is a candidate key Example: Normalization Example: Normalization FDs Example: Normalization fd1 propertyNo, iDate → iTime, comments, staffNo, sName, carReg (Primary key) fd2 propertyNo→ pAddress (Partial dependency) fd3 staffNo→ sName (Transitive dependency) fd4 staffNo, iDate→ carReg fd5 carReg, iDate, iTime→ propertyNo, pAddress, comments, staffNo, sName (Candidate key) fd6 staffNo, iDate, iTime→ propertyNo, pAddress, comments (Candidate key) Example: Normalization INF to 2NF Property (propertyNo, pAddress) PropertyInspection (propertyNo, iDate, iTime, comments, staffNo, sName, carReg) Example: Normalization Property fd2 propertyNo → pAddress PropertyInspection fd1 propertyNo, iDate → iTime, comments, staffNo, sName, carReg fd3 staffNo → sName fd4 staffNo, iDate → carReg fd5′ carReg, iDate, iTime → propertyNo, comments, staffNo, sName fd6′ staffNo, iDate, iTime → propertyNo, comments Example: Normalization 2NF to 3NF Property (propertyNo, pAddress) Staff (staffNo, sName) PropertyInspect (propertyNo, iDate, iTime, comments, staffNo, carReg) Example: Normalization Property fd2 propertyNo → pAddress Staff fd3 staffNo → sName PropertyInspect fd1′ propertyNo, iDate → iTime, comments, staffNo, carReg fd4 staffNo, iDate → carReg fd5′ carReg, iDate, iTime → propertyNo, comments, staffNo fd6′ staffNo, iDate, iTime → propertyNo, comments .

• Cơ sở dữ liệu
• Database System
• Lecture Database Systems
• Relational databases
• Database design
• Relational databases
• Hierarchical model
• Tree structure diagrams
• Database system concepts
• Lecture Database system concepts
• Database systems
• Database languages
• Database system architectures
• Relational database design
• Lecture Database System
• Database system architecture
• File based approach
• Data management systems framework
• Recovery system
• Database architecture
• Database approach
• Database design process
• Query optimization
• Transaction state
• Concurrency control
• Data analysis
• Information retrieval
• Parallel databases
• Distributed databases
• Advanced application development
• Advanced data types
• Advanced transaction processing
• Relational model
• Basic query structure
• Dynamic SQL
• Tuple relational calculus
• Entity relationship model
• Application design
• Object­ based databases