Database Reference
In-Depth Information
Code change identifi cation can be made at different levels. The more details we want,
the more sophisticated the change identifi cation tool should be. With more details, identify-
ing change impact will be easier and more informative.
Change Impact Identifi cation
A change made to one component affects other database components due to component
dependencies. Therefore, to identify the impact of change, we should identify the dependen-
cies that exist between database application components and then fi nd the ripple effect of
change due to the transitivity of the dependency relations. The Component Firewall technique
presented below is used to determine all the affected database components.
Component Dependency
Each type of database objects is handled separately to determine the dependencies it
creates. In Table 1, we give an example of the dependencies that exist between database
components.
Component Firewall
A Component Firewall is a set of affected modules when some changes are made to any
of the database components. A database component is marked as modifi ed and is included
in the Component Firewall if one of the following conditions is satisfi ed:
(a) Its defi nition is modifi ed.
(b) It is deleted.
(c) It is dependent on a modifi ed or deleted component.
Table 1: An example of database components dependency
Database Component
Dependent Component
Table
Primary key constraint
Foreign key constraint
Check constraint
Index
View
Synonyms
Trigger
SQL-PSM code
SELECT statement
INSERT statement
UPDATE statement
DELETE statement
