6

12FDFDFD341NF2NF3NFBCNF2NF3NF 5MVD4NF5NF

6.1 6.2 6.3 6.4 6.5 6.6 4NF

6.1 StuDB S_C_GS#SNSDSACCNGPC12

S_C_G SSSNSDSA CCCNPC S_CSCG

6.2 1(Functional DependencyFD)

SSSNSDSAS #SDSSNSSAS,CG6.1R(U)UA1A2AnXYUtuRtuXt[X]=u[X]t[Y]=u[Y]t[X]u[X] => t[Y]u[Y]XYYXXY

2 X, XX , XZX6.2XYYX

YXSDTS #SD,SDDTS#DTDTS#SDS#

3 (Super Key)SSSNSDSACC,CN,PCS_CSCG

S#C#S#C#SCS_C (S#SN)(S#SD)

6.3 6.3.1 6.3.2 Armstrong 6.3.3

6.3.1 XYYZXZ XYYZ XZ : 6.6FR(U)XYRFFrXYFXYXYFFXY

FF+ 6.7FFClosureF+F+XYFXYRXYZFXYYZF+

6.3.2 Armstrong 1Armstrong 3 A3(Transitivity)XYYZXZ

2 1(The Union Rule) XYXZ XYZ3(The Pseudo Transitivity Rule) XYWYZ XWZ 1XY XXYA2 XZ XYYZ A2 XYZ A33XYWXWY A2 WYZ XWZA3

6.2R(A,B,C,D,E)F=ABCD,AB,DEFAE6.1Ai(i=12,n)R X(A1A2,An)XAi AB AAB A2 ABCD ACD A3 ACAD DE AE A3

6.8:R(U),U={ A1A2,An},XU,FUXF AiAiUXAiFR(A,B,C)F=AB,BCABC

6.1

1X(i+1)= X(i) 2X(i+1) 3FX(i) 4FV X(i)VW

6.3.3 6.9FGRUF+=G+FGF=GFGGFFG

6.1GGG

F

6.10:FFFmin(1) F(2) FXAFXAF(3) FXA, FXAZAFZX

6.5FAHCCACHDCEGEHC CGDH CEAGACDH (1)F11AHCCACHDACDH CECGCEG EHC CGHCGDCGDH CEACEGCEAG (2) FCACEACACGDACDHCGHCEACGHF (3) CA, ACDHACDHACDHACDH F FAHCCACHDCDHCECGEHCCGDCEG

6.4 6.4.1 6.4.2 6.4.3

6.4.1 6.6R(U,F) USNOSNAMEDNAMEDADDR FSNOSNAMESNODNAMEDNAMEDADDRR1 =R1{SNO,SNAME},{SNOSNAME} R2 {DNAMEDADDR}, {DNAMEDADDR}

1

2R={R1 ({SNO,SNAME,DNAME},{SNOSNAME,SNODNAME} ), R2{DNAME,DADDR}{DNAMEDADDR}}

2 1 FSNOSNAMESNODNAMEDNAMEDADDR F1F2SNOSNAMEDNAMEDADDR F+{SNOSNAME,SNODNAME,DNAMEDADDR,SNODADDR} (F1F2)+SNOSNAMEDNAMEDADDR 2 FSNOSNAMESNODNAMEDNAMEDADDR F1F2SNOSNAME,SNODNAME,DNAMEDADDR F+{SNOSNAME,SNODNAME,DNAMEDADDR,SNODADDR} (F1F2)+ {SNOSNAME,SNODNAME,DNAMEDADDR,SNODADDR}

6.4.2 1 RF Frr = m(r)

r m(r)

6.4

2 16.2

1(1)nkRi1ikAj1jn(2) AjRiijajbij(3) FXYFXYYXXYajbijajajbiji(4) a1a2,ak

R(U,F)U =(A,B,C,D,E),F=(AC,BC,CD,DEC,CEA)R{R1(AD)R2 (AB)R3(BE) R4(CDE) R5(AE)}6.2(1)(2)(a)AC(a)b13b23b53b13b13b23b53BCb33b13R2b13(b) CDD4b24b34b54a4c(AC,BC)DECC3345b13a3b13a3d(BC, AC, CD)CEAA1345b31BCb41ACa1a1e

26.5= R1,R2RFRF, R1R2R1R2 F+R1R2R2R1F+

6.8R({S,SN,C,G}{SSN,(S,C)G})={R1({S,SN},{SSN})R2({S,C,G},{(S,C)G})}R1R2=S#R1R2=SNR1R2R1R2S#SNF6-86-9

6.4.3 6.13R,FRZRZF+FZz(F)

R(A,B,C,D)F{AB,CD}=R1({A,B}{AB})R2{C,D}{CD}F{AB,CD}F1F2{AB,CD} F+ = (F1F2)+

R(A,B,C)FABCB=R1({A,B}{AB})R2{A,C}{AC}R1R2=A, R1R2=BR2R1=CR1R2R1R2= ABFF{AB,CB}F1F2{AB,AC},F+ (F1F2)+

6.5 6.5.1 E. F. Codd1970 (1)(2) (3)(4)(5)XNFX,NF(Normal Form)

11NF 6.141NFRRR1NF,1NFP (PNOPNAMEQOH,PJ(PJNO,PJNAMEPJMNOPQCP P(PNO,PNAME,QOH,PJNO,PJNAME,PJMNO,PQC1NF Pl (PNO,PNAME,QOH) PJl (PNO,PJNO,PJNAME,PJMNO,PQC) PJl

22NF 6.152NFR1NFRR2NF1NF2NFPJ1 PJ2 (PNO,PJNO,PQC) J(PJNO,PJNAME,PJMNO)

33NF 6.163NFR2NF,R3NFS ST (SNONAMEDNAME DEPT(DNAMEDADDR)S (SNOSNAMEDNAMEDADDR),SNODADDRSNODNAME,DNAMEDADDRSNODADDR,DADDR3NF3NF

4Boyce-CoddBCNF) S (NAME,SEX,BIRTH,ADDR,DNAME)NAME,SEX,BIRTHADDR(NAME,SEX)(NAME,BIRTH)(NAMEADDR)A(ADDR,DNAME)6.17BCNFRF,XARAXRXAXRRBCNFRBCNF(1)A(R2NF)(2)(R3NF)(3)

SNOCNOTNOSNOTNOCNOTNOCNOSNOCNOSNOTNOSTC2NFSTC3NFFTNOCNOTNOSTCBCNF 6.13STCSNOTNOCNOSNOTNOCNOST

STCSNOTNOCNOSTSNOTNOTCTNOCNOBCNF

1NF3NFBCNF2NF

6.5.2 (1)BCNF(2)3NFBCNF(3)3NFBCNF

1BCNF 6.6(1) FR=R1R2,RkRFFiFRiXYRiXYF+1=S1,S2,,SmRiFiRR1R2,Ri1,S1,S2,,SmRi+1RkF(2) 2=R1R2,Rk,Rk+1RnR,2F

BCNF R(UF)=R1(U1,F1)R2(U2,F2)Rk(Uk,Fk)BCNF610RBCNF ={R} BCNF SBCNFSXAXSAXS1XAS2SAS1S2S

6.14CTHRSG(C,T,H,R,S,G)F= CSG, CT,HRC , HSR, THR(1) AAA,GHSHS(HS)+ (HS)(0) =HS (HS)(1) =HSR (HS)(2) =HSRC (HS)(3) = CTHRSG (HS)(4) = CTHRSG(HS)+=CTHRSGHSCTHRSG

(2) FXAXRARR1(X,A)R2(S-A)CSGCTHRSGCSG,CTHRSF+CSGCTHRSCSG(F)=CSGCTHRS(F)=CT,THR,HRC,HSRF1CSGBCNFCTHRSBCNF(2-1)CTHRSHS(2-2)CTHRSCTCTHRS CTHRS{CT,CHRS}CTCTCHRSCHRHSRHRCCT(F1)=CTCHRS(F1)=CHRHSRHRCF2,CTBCNFCHRSBCNF(2-3) CHRSHS(2-4) CHRSCHRCHRS CHRS{CHRCHS}F2CHRCHSCHR(F2)=CHRHRCCHS(F2)=HSCCHRHCHRCHSHSCHRCHSBCNF

23NF 6-43NFRF3NF(1)RFF R(2)FRR;(3),XAXAFXAlXA2XAnFXAlA2AnXAi(i=1,2,n)6-15F={{CT,CSG,HTR,HRC,CHR,HSR,KEYHS} = {CT,CSG,HRT,CHR,HSR}

33NF 6-113NF3NFXRXR3NF,

6.6 4NF 6.6.1 BCNF(CTB)

6.6.2 R(U)X,YUZ=UXYstuv

6-23R(U),X,YUZ=UXYXYRr(X,Z)YZ

1 (1) MVD0(Complementation) XYXUXY(2) MVD1:(Reflexivity) Y X UXY(3) MVD2(Augmentation) XYV WWXVY(4) MVD3(Transitivity) XYYZXZY

2 (1) MVD4 XYWYZXWZWY(2) MVD5 XYXZXYZ(3) MVD6 XY XZXYZXYZXZY

6.6.3 4NF TEACHC_TC_B,BCNF4NF4NFBCNF

6.194NF:R(U)lNF,XY(YX)XR(U)R4NFTEACHC_T(C,T)C_B(C,B)CTCBC_T4NFC_B4NF

TEACHBCNF4NFTEACH (C,T,B):CTCBCTBTEACHBCNFCTEACH 4NF

XYXYFDFD

R3NFRFDRBCNFRFDBCNFFD3NFFD