Databases Reference
In-Depth Information
Complex data type
Table
(data structure
with primary key)
In case of
multi-
occurrence
A multi-occurrence nested data
type is limited in terms of the
number of occurrences
presented on a screen. There are
no systems of pagination. The
loading of a page can slow
down response time.
A Table is a multi-occurrence
data type without any limitations
on display, since a pagination
mechanism is managed by the
tool.
Display
performance
remains stable.
Triggering
processing
It is possible to attach
operations to a complex data
type by linking the type to an
implementation class (Java).
A table can accept the
declaration of triggers, both pre-
and post-operation on CRUD
services.
Table 10.1.
Comparison between the use of complex data types and tables
(PK: Primary Key; FK: Foreign Key)
Indeed, the target being a Model-driven MDM system, the
latter is capable of retaining the multi-valued attributes by
ensuring data integrity: it automates the adoption of normal
forms of the relational oriented approach. This also has an
impact on the derivation of many-to-many associations
because it becomes possible to hide join tables. From these
starting principles, the derivation rules of semantic classes
towards a logical data model cover numerous cases of
modeling, notably the following:
− association oriented inside the same category;
− association oriented in different categories;
− association not oriented in the same category;
− association not oriented between different categories;
− qualified association (qualifier attribute);
− recursive association;
− composition in the same category;
− composition between different categories;
