There are numerous temporal extensions that have been proposed and implemented by extending the
relational data models [6], [8].
They can use SQL as they can use XPath to retrieve data from both XML and
relational data model.
The recognition accuracy comparison results of
relational data model and nonrelational data model to different events are listed in Table 5, finding that the
relational data model has higher recognition accuracy compared with the nonrelational data model.
The students do not need expansion of the knowledge concerning the
relational data model in the future, which, despite all the advances in IT, is nearly 100% presented in current DBMS.
Development of e
relational data model is based on the transformation of the analytical models in the process of data modelling.
The functional dependency in the
relational data model and the child-parent relationships in the hierarchical data model are typical examples.
Edgar ("Ted") Codd introduced a simpler model: the
relational data model. A year after his original 1969 IBM research report on the subject, Codd published a revised version for a wider audience (Codd, 1970) where he first argued that relations should be normalized so that each data entry would be atomic--we now call this first normal form.
Emphasis was put on constructing a
relational data model supporting the above logic, see Figure 2.
Gartner defines RDBMS as a database management system that incorporates the
relational data model, normally including a Structured Query Language (SQL) application programming interface.
With dozens or hundreds of normalized tables in a database, active archiving preserves data from even the most complex
relational data model, maintaining its relational integrity with 100 percent accuracy.
In contrast to other probabilistic data models (see Section 8) which are only loosely related to the
relational data model, PRA is a generalization of relational algebra.