<p class="MsoListParagraph" style="margin-left: 18pt; text-indent: -18pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">1.<span style="font-size: 7pt; line-height: normal; font-family: 'Times New Roman'"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">The following relation schema R, functional dependency set F and decomposition set ρ are given.<o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 36pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">R(S,A,I,P), F={S→A,SI→P}, ρ={R<sub>1</sub>(SA), R<sub>2</sub>(SIP)}, <o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 36pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">Please check if ρ keeps </span><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif">Lossless-join property<o:p></o:p></span></p> <p class="MsoNormal"><b><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span></b><b><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">Sol)<o:p></o:p></span></b></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>1</sub>(SA) </span><span lang="ZH-CN" style="font-size: 9pt; font-family: '맑은 고딕'; color: red">∩</span><span class="apple-converted-space"><span lang="EN-US" style="font-size: 9pt; font-family: '맑은 고딕'; color: red"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>2</sub>(SIP) </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">→ </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>1</sub>(SA)</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> - </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>2</sub>(SIP)</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> (o)<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">[</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>1</sub>(SA) </span><span lang="ZH-CN" style="font-size: 9pt; font-family: '맑은 고딕'; color: red">∩</span><span class="apple-converted-space"><span lang="EN-US" style="font-size: 9pt; font-family: '맑은 고딕'; color: red"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>2</sub>(SIP)</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">= S<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>1</sub>(SA)</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> - </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>2</sub>(SIP)</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> = A,<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">as F(S</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">→</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> A</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">,SI→P</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">) ]<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">S</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">→</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">A<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">Thus<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>1</sub>(SA) </span><span lang="ZH-CN" style="font-size: 9pt; font-family: '맑은 고딕'; color: red">∩</span><span class="apple-converted-space"><span lang="EN-US" style="font-size: 9pt; font-family: '맑은 고딕'; color: red"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R<sub>2</sub>(SIP) →</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">R1<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"> </span></p> <p class="MsoNormal"><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">That is </span><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">Lossless-join</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: -18pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">2.<span style="font-size: 7pt; line-height: normal; font-family: 'Times New Roman'"> </span></span><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif">Given the following relation schema </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">R, where U={A</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">B</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">C</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">D, E, G}, <o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">F={AB→C, C→A, BC→D, ACD→B, D→EG, BE→C, CG→BD, CE→AG}, Please calculate the</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: #0070c0"> </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">Canonical Cover of F.<o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 24pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span></p> <p class="MsoListParagraph" style="margin: 0cm -24.15pt 0.0001pt 18pt; text-indent: -18pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">3.<span style="font-size: 7pt; line-height: normal; font-family: 'Times New Roman'"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">Please tell the level of the highest normal form, then decompose it to BCNF if it is not in BCNF. <o:p></o:p></span></p> <p class="MsoListParagraph" style="margin: 0cm -33.3pt 0.0001pt 39.3pt; text-indent: -18pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">(1)<span style="font-size: 7pt; line-height: normal; font-family: 'Times New Roman'"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">R={SNO,SNAME,PNO,QTY} <br />F={SNO→SNAME</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">SNAME→SNO</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">(SNO,PNO)→QTY, (SNAME,PNO)→QTY}<o:p></o:p></span></p> <p class="MsoNormal"><b><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span></b></p> <p class="MsoNormal"><b><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span></b><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"><o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 39pt; text-indent: -18pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">(2)<span style="font-size: 7pt; line-height: normal; font-family: 'Times New Roman'"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">SP={ <u>SNO</u>,SNAME,CITY,STATUS }, <o:p></o:p></span></p> <p class="MsoNormal" style="text-indent: 21pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> F={ SNO→SNAME,SNO→CITY, CITY→STATUS }<b> </b><o:p></o:p></span></p> <p class="MsoNormal" style="margin-left: 1cm; text-indent: 16.2pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span></p> <p class="MsoListParagraph" style="margin-left: -0.1pt; text-indent: 0.1pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">4.<span style="font-size: 7pt; line-height: normal; font-family: 'Times New Roman'"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">R(A,B,C,D)</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">F={A→B,C→D}, R</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">∈</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">2NF</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">?</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> ρ={R<sub>1</sub>(AB)</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">R<sub>2</sub>(CD)} , is ρ with </span><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif">Dependency Preservation </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">and </span><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif">Lossless-join properties</span><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif">?</span><span lang="EN-GB" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"><o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif"> </span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: -18pt"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">5.<span style="font-size: 7pt; line-height: normal; font-family: 'Times New Roman'"> </span></span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">Given R(A,B,C,D)</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">F={D</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">→</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">B,C</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">→</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">A,A</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">→</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">C},please give the candidate keys, and determine whether R is in 2NF</span><span lang="ZH-CN" style="font-size: 12pt; font-family: SimSun">,</span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif">if not, decompose R into 2NF.<o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red">CK: (A,D),(C,D) </span><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"><o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"><br /></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"><br /></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"><br /></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"><br /></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><span lang="EN-US" style="font-size: 12pt; font-family: 'Times New Roman', serif; color: red"><br /></span></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><font face="Times New Roman, serif" size="3"><span style="line-height: 24px">제가 데이터베이스를 막시작하는 학인데 외국어로 배우니 힘든면도 있고</span></font></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><font face="Times New Roman, serif" size="3"><span style="line-height: 24px">이해하더라도 약간 안개식으로 감이 잡혀서 ㅠㅠ</span></font></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><font face="Times New Roman, serif" size="3"><span style="line-height: 24px">답과 설명좀 해주실분 부탁드리겠습니다 ㅠㅠ</span></font></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><font face="Times New Roman, serif" size="3"><span style="line-height: 24px">일단 이렇게 풀긴했는데 혹시그것마져도 틀린것이 있으면</span></font></p> <p class="MsoListParagraph" style="margin-left: 18pt; text-indent: 0cm"><font face="Times New Roman, serif" size="3"><span style="line-height: 24px">어느부분이 틀렸는지 말씀해주시면 감사하겠습니다</span></font></p>
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