02 Distributed DBMSTechnology
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A distributed database is a database that is controlled by a central database management system where storage devices are not attached to a common CPU. Distributed databases ensure data across locations remain up to date through replication and duplication processes. A distributed database management system makes the distribution transparent to users and jointly refers to the distributed database and management system.
02 Distributed DBMSTechnology
- 1. Ins to FOR-IAN V. SANDOVAL truc r: ls u_it@ ya o o p ho .c m fvs nd va ya o o a o l@ ho .c m
- 2. A distributed database is a database that is under the control of a central database management system (DBMS) in which storage devices are not all attached to a common CPU Collections of data (e.g. in a database) can be distributed across multiple physical locations. To ensure that the distributive databases are up to date and current, there are two processes: replication and duplication
- 3. Besides distributed database replication and fragmentation, there are many other distributed database design technologies.
- 4. A distributed database management system ('DDBMS') is a software system that permits the management of a distributed database and makes the distribution transparent to the users. Sometimes "distributed database system" is used to refer jointly to the distributed database and the distributed DBMS.
- 5. Figure 2.1 – Example of Distributed Database System.
- 6. A database Users access the distributed database through: 1. Local Applications 2. Global Applications A distributed database does not share main memory or disks.
- 7. ACID (Atomicity, Consistency, Isolation, and Durability) is a set of properties that guarantee that database transactions are processed reliably. A-atomicity: the transaction takes place as whole or not at all. C-consistency: maps one consistent DB state to another I-isolation: each transaction sees a consistent DB. D-durability: the results of a transaction must survive system failures
- 8. 1. Reflects organizational structure 2. Local autonomy 3. Protection of valuable data 4. Improved performance 5. Economics 6. Modularity 7. Reliable transactions
- 9. 1. Complexity 2. Economics 3. Security 4. Difficult to maintain integrity 5. Inexperience
- 10. 6. Lack of standards 7. Database design more complex 8. Additional software is required 9.Operating System should support distributed environment 10. Concurrency control