Change Data Capture
Intent
(A description of the goal behind the pattern and the reason for using it.)
To capture all changes in data in a source system as they happen, so that any changes in records can be easily loaded and retained in another data repository.
Also Known As
(Other names for pattern)
None
Motivation
(A scenario consisting of a problem and a context in which this pattern can be used)
- Using changes in the data to record a behaviour which drives an analytical model. For example the constant changing of a vendors bank account number to indicate employee fraud using bogus invoices.
- Using changes in data to report on the value of a record at a point of time. For example loading changes of address as slowly changing dimensions to enable reporting of a persons address at any point of time
- To remove the need to alter the source application or database to capture changes made. For example reading the database redo logs so that all changes are automatically captured, without the need ot placing manual triggers in the database or to build a auditing capability within the source application.
Applicability
(Situations in which this pattern is usable; the context for the pattern)
Structure
(A graphical representation of the pattern. Class diagrams and Interaction diagrams may be used for this purpose)
Participants
(A listing of the classes and objects used in the pattern and their roles in the design.)
Collaboration:A description of how classes and objects used in the pattern interact with each other.
Consequences:A description of the results, side effects, and trade offs caused by using the pattern.
Implementation:A description of an implementation of the pattern; the solution part of the pattern.
Sample Code:An illustration of how the pattern can be used in a programming language.
Known Uses:Examples of real usages of the pattern.
Related Patterns:Other patterns that have some relationship with the pattern; discussion of the differences between the pattern and similar patterns.