Databases Reference
In-Depth Information
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the second is object-oriented in inspiration, with the
use of an Object Oriented Database System or strictly based
on XML use. The loss of the benefits of the relational
approach and the differences with object orientation and the
hierarchical XML approach do not enable us to profit from
all these architecture styles in the same data model;
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the third architecture style brings together the
relational, the object and the benefits of XML schemas, all at
the same time. This results in a “semantic” logical data
architecture style that uses the multi-evaluated attributes of
foreign keys, mixing together the relational approach and
the object oriented approach, but which also allows the
attachment of rules (facets, data triggers) and nested data
types (Russian doll).
The implementation of a logical data model in semantic
architecture style requires the use of an MDM tool capable of
supporting such a model.
In the modeling procedures describe in this topic, we will
concern ourselves with this type of MDM, which is able to
support the Model-driven approach, in other words rich data
models. To obtain an automatic alignment of the data
governance functions with the models, without developing
specific software, rich data models must be at hand which
can unify the quality of the repository via the referential
integrity constraints mechanism of the relational oriented
approach, the flexibility and the expressivity of the object
oriented approach and the power of the procedural
attachment of data (facets, data triggers). This type of
representation is available, at the software level, thanks to
the use of XML schema standards. This then replaces the
classic relational Data Description Language (DDL)
5
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5
. Data Description Language. The most classic DDL is that of the
description of tables in SQL (Create Table, Alter Table, Create Index, etc.).
A relational DDL remains unavoidable for transactional systems (On Line
