Changes between Version 2 and Version 3 of FDORfc7

Timestamp:

Jul 30, 2007, 7:19:02 AM (17 years ago)

Author:

barbarazoladek

Comment:

--

FDORfc7

@@ -27 +27 @@
 == Motivation ==
 
-Existing !FdoClassDefinition does not contain any information that would allow to determine a type of the base RDBMS object.
-There are cases when view-based classes should be distinguished from table-based classes to be able to handle behavioral differences:
+The motivation for this RFC is to expose classes based on virtual objects. The significat differenece between classes based on real and virtual objects is that the later do not contain any data themselves. An RDBMS view is an exmaple of the virtual object. It is really an SQL query. An FDO class based on that query exposes data that is contained in other objects referenced in the query. The class schema characterists like property types and constraints tightly depends on the these objects. Data exposed by the class is more dynamic as it can be edited or deleted from the objects that contain it. 
 
- * Editing schema. View definition cannot be changed and therefore class schema cannot be changed.
+How these classes can be used? Classes based on virtual objects can be used for limiting or restricting access to some data, for analysis where a class exposes data that is combination of many classes joined in certain way with sometimes complex conditions.
 
- * Editing property values. Class data may not be editable.
-
+Why is it important to distinguish these classes in FDO? These classes virtuality cannot be expressed by any existing methods of !FdoClassdefinition. In fact, their characteristics are somewhat unpredictable and depend on the underlying virtual object definition.
 
 == Proposed Solution ==