[DM] BEA_002

Data Model:  specification too fuzzy

The Data Model misses certain consistency constraints that seem
to be required to preserve a data model instance internally consistent.

Examples are:
(a) is it true that if a node has a base uri propery, then all the 
descendants
have the same base-uri property?
(b) is it true that if a node has the nillability property being true, 
then it has
no text  and elements nodes as children, and it has an attribute 
xsi:nil="true"?
(c) if the type annotation of an element is a certain Qname different 
from xdt:untyped
and the element has  an attribute xsi:type, then are the value of the 
attribute and the type
annotation required to be the same ?
(d) etc

If the data model is generated via Infoset or PSVI it is relatively 
clear that those extra constraints
are not violated. The problem is that Data Model instances can be 
generated
directly by applications from other input structures (e.g SQL records, 
COBOL structures) etc.

The concern is that the application generated data model instances 
(other then Infoset and
PSVI) do not have a set of rules and constraints clearly spelled out 
that they will have to satisfy
to create correct data model instances.

Received on Monday, 16 February 2004 00:07:26 UTC