Introduction

Main topics

1. DB architecture/technologies
2. Triggers
3. ORM and JPA
4. Physical DBs / Query optimization
5. Ranking and skylines

System schema

DBMS box

• Transaction management
• Concurrency control
• Reliability manager
• Physical data management and query optimization
• Data distribution

Application box

• Mapping objects to tables and methods to transactions
• Managing the alignment between object state in main memory and data state in secondary memory

Transactions

It is the atomic unit of work.

Within a transaction, one of the following commands is executed the end of the transaction:

• commit-work (commit);
• rollback-work (abort).

ACID properties

• Atomicity
  • Abort-rollback-restart, commit protocols
  • Reliability manager
• Consistency
  • Integrity checking of the DBMS
  • Integrity Control System at query execution time (with DLL compiler)
• Isolation
  • Concurrency control
  • Concurrency Control System
• Durability
  • Recovery management
  • Reliability Manager