SDO DataGraph object should support many data graph roots

["Miro Kandic (mkandic)" <mkandic@cisco.com>]

Based on the definition of SDO v2.1 data graph's root object it can be
understood as object not contained by any other object in a data graph.
So, the root object is top container object.

Analyzing then data graph that consists of the data objects from Order
Management (OM) use case, the use case used in the specification and
probably the most used use case in the software literature, it is
obvious that this data graph has many top container objects: Customer,
Order and Product. Only OrderLine object are contained by some other
object (Order).

Since SDO v2.1 DataGraph can have only one root object it actually
represents a tree, it is not a graph at all and as such cannot carry the
data graph defined by this the most basic use case.

 

SDO DataGraph object should support many data graph roots.

 

The developers are forced to add an artificial object to a domain schema
in order to provide missing SDO support and that object plays role of
true data graph with many top container objects. It is artificial entity
type in the schema because it does represent anything in domain. It is
rather a part of the infrastructure, more precisely, is the part of the
data technology. Since SDO claims to be a data technology then it should
be part of SDO.

 

Miro Kandic
(408) 525-2596