Copying or distributing in print or electronic forms without written permission of
Idea Group Inc. is prohibited.
ing out as a standard for representing, exchanging, and publishing semistructured
information (Abiteboul et al., 2000).
In Papakonstantinou et al. (1995), the authors propose the object exchange model
(OEM) which is a graph-structured data model where the basic idea is that each
object has a label that describes its meaning.
An OEM label is a tuple (label;type;value;object-ID) where label denotes the kind of the
object, type is a data type (atomic, composed, or reference), value denotes the actual
value of the object, and object-ID represents a unique variable-length identifier for
the object. The OEM label is used to extract information about objects that represent
the underlying data. The OEM model represents semistructured data by means
of graphs where nodes denote objects or values and edges represent relationships
between objects; in particular an OEM graph is a directed labeled graph where
the edge labels describe the pointed nodes. OEM does not actually represent the
semantics of relationships between objects; that is, if an object pointed by an edge
labeled as ???Person??? is connected by means of an edge labeled as ???City??? to another
object, OEM allows one to represent only the fact that the object City is contained
in the object Person, but does not express in which relationship they are.
Pages:
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517