Distinguish between reprocessing and rollforward as database ...

[09madisonrousseau09]

Distinguish between reprocessing and rollforward as database recovery techniques.
 
  What will be an ideal response?

Question 2

Distinguish between a data model and a database design.
 
  What will be an ideal response?

[strudel15]

Answer to Question 1

Reprocessing and rollforward both require the use of database saves, which are backups of the database at a known state. Reprocessing as a means of recovery involves recovering the database from the last database save and having the application programs reprocess all the transactions since the save. Rollforward as a means of recovery involves recovering the database from the last save and then reapplying all changes to the database. Reprocessing does not always reproduce the original database contents correctly since minute changes in processing by the application programs may result in changes in data manipulation.

Answer to Question 2

The data model is a representation of the content, relationships, and constraints of the data needed to support the users' requirements for the system. The data model is a logical representation of business requirements. The database design is created from the data model to include tables, relationships, constraints, data types, column properties, and descriptions of primary and foreign keys. The database design is a component design of how database technology can accomplish the support of the system requirements depicted in the data model.

[09madisonrousseau09]

Excellent

[okolip]

TYSM