<ConceptModelerER><Chapter><string>M3.02.ER Restructuring</string></Chapter><Title><string>Introduction</string></Title><Instructions><string>&lt;html o=&quot;urn:schemas-microsoft-com:office:office&quot; xmlns=&quot;http://www.w3.org/TR/REC-html40&quot; w=&quot;urn:schemas-microsoft-com:office:word&quot;&gt;&#xa;  &lt;head&gt;&#xa;    &lt;style type=&quot;text/css&quot;&gt;&#xa;      &lt;!--&#xa;        li.msonormal { margin-bottom: .0001pt; font-family: Times New Roman; margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; font-size: 12.0pt }&#xa;        p.msonormal { margin-bottom: .0001pt; font-family: Times New Roman; margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; font-size: 12.0pt }&#xa;        div.msonormal { margin-bottom: .0001pt; font-family: Times New Roman; margin-top: 0cm; margin-right: 0cm; margin-left: 0cm; font-size: 12.0pt }&#xa;      --&gt;&#xa;    &lt;/style&gt;&#xa;    &#xa;  &lt;/head&gt;&#xa;  &lt;body lang=&quot;DE-CH&quot;&gt;&#xa;    Both the E-R model and the relational model are abstract, logical, &#xa;    representations of a given reality. The two models employ similar design &#xa;    principles and it is therefore possible to convert an E-R design into a &#xa;    relational one (and vice versa).&#xa;&lt;hr&gt;&#xa;&#xa;Formally, the constructs of an E-R diagram are converted into relations.&#xa;&lt;hr&gt;&#xa;&#xa;The conversion of an E-R diagram into a relational database schema is actually &#xa;    a translation process based on a few translation rules.&#xa;&lt;hr&gt;&#xa;&#xa;An E-R diagram needs to be restructured (cfr E-R Restructuring), to resolve &#xa;    all the problematic constructs, before this translation process can begin.&#xa;&lt;hr&gt;&#xa;&#xa;In principle, each entity set and each relationship set will result in a &#xa;    corresponding relation. In practice, some relationship sets may be &#xa;    disregarded, in some particular situations, to avoid data redundancy.&#xa;  &lt;/body&gt;&#xa;&lt;/html&gt;&#xa;</string></Instructions><Problem><GERM id="0"/><GERD id="1"><model><GERM ref="0"/></model><figures/></GERD></Problem><Solution><GERM id="2"/><GERD id="3"><model><GERM ref="2"/></model><figures/></GERD></Solution></ConceptModelerER>