?? SL, ?? PJ

1
? ???????
2
????

• ?? SL, ?? PJ
• ?? JN, ? UN
• ????CP,?DF, ??

3
??????

• ?????????? (SDD-1??)
• ???????????

4
???(Semi_Join)

• R S ?R( R S)
• ????????
• R R SJ S ? R ??SJ??
• R (R SJ (R SJ T)) ? R ??SJ????

5

• ??

R
S
T
R,S,T??????
S
CC
BB
T
R
AA
?R?????
TT SJ S
RR SJ T
SS SJ R
?????
6
RR SJ T
TT SJ S
SS SJ R
?????
RR SJ T ?
??????
????????????????????????
7
????

• ?????
• Card(R) ????R?????
• Size(A) ??A???(????)
• Size(R) ???????, ??????
• Val(AR) ??A?R???????

8
????????????

• ?? ?????
• R S ? (R S) S or
• R (S R) or
• (R S) (S R)

9
????????????-?

• R S (R S) S
• ??????
• ???B S ?site r
• Cost C0C1Size(B)Val(BS)
• ?r????SJ, ????, ?RR SJAB S
• ??R?site s, ??
• Cost C0C1Size( R )Card (R)
• ?r????JN,?????
• ???
• CSJ2C0C1((Size(B)Val(BS) Size( R)
  Card (R))

10
Example R S

• A B

A C
S
R
R S
AA
?A R 2,10,25,30
A B
A C 10 y 25 w
S R
AA
11

• A B A C
• R S

2 a
3 x
10 b
10 y
25 c
15 z
30 d
25 w
32 x

• ??????
• ????? R (S R)
• T 4 A 2 AC
• ???? R S
• T 4 AB

12
???????

• SJ ???
• (R SJ S) JN S ???CSJ
• ( S SJ R) JN R ???C SJ
• CSJ2C0C1((Size(A)Val(AR) Size( S)
  Card (S))
• ??CSJ?CSJ, ????

13
SDD-1??

• ????SJ??????????
• ????SDD-1?????

14
????????

• ????????????????????
• ???or????
• ?????????????????
• ????-???????????-???
• ????-?????????-????

15
??????(R??)

• ??????
• R JN S ???R???? O, ??S???? I,
• I/o???????????, CPU??????JN?????

16
??????-??

• ?????????
• ????
• C?? (NoutCard(O)Nin)CI/o
• Card(Result)Ccpu
• Nout ??O??? Nin ?O???????I?????
• ????
• C??(NoutNin)CI/OCsort(I)Csort(O)
• Card(Result)Ccpu
• ?????????,????????

17
??????-???

• ??????
• ?????
• ??I, ????I??????,I??????
• ??O, ?I???????????, ?????O??
• ?????
• ????????,??????,???????????,???????,??????

18
??????-?

• ??????????
• ??, O?????, ??
• C1C??CmesCard(O)Size(O)/m
• ??, O?????, ??
• C2C??CmesCard(O)Size(O)/m

19
??????-?

• ??, I?????
• C3C??CmesVal(AO)(1NISize(I)/m)
• NI ????O??????, ????????????
• ??, I?????
• C4C??CmesVal(AO)(1NISize(I)/m)

20
??????-?

• ??, I?????, ?????
• C5C??CmesCard(I)Size(I)/m2NinCI/O
• ??, ????????site
• C6??????????(C??/C??)
• R??????????JN????????JN??.

21
?????????

• ????
• ???????????
• ???????
• ?????????????
• Hash????

22
???????????
23
???????????-?

• ????
• ???Ri??Fi1?Fi2, Rj??Fj1?Fj2
• ??Ri?Rj???A?????
• Ris A Rjt ? , ??s ? t,
• ??Ri?Rj???A?????
• ????
• Ri A Rj U (Fis A Fjs),
  ?????????????????s???
• ??????????????

24
???????????-?
Ri
Rj
????
Ri
Rj
Result
25
???????????-?

• ??
• ?Ri?Rj???A?????,?Ri?Rj?????A????B??????
• ?Ri?Rj???A?????,????(????)B????A,?A ?
  ?,?Ri?Rj?B??????
• ?Ri?Rj???A?????,??Rj?Rk???B?????,?(Ri ARj
  B Rk) ?(Fis A Fjs B Fks)
• ??Ri A Rj B Rk???????????????????

26
??

• Student(s, sname, age, d)
• Dept(d, dname, l, header)
• Location (l, area, mgr)

27
Site 1
Site 2
Site 3
S2 D2 L2
S1 D1 L1
S3 D3 L3
S1 ? dlt10(Student) S2 ?
d10andd20(Student) S3 ? dgt20(Student) D1
Dept SJ S1 D2 Dept SJ S2
D3 Dept SJ S3 L1 Location SJ D1
L2 Location SJ D2 L3 Location
SJ D3 Student Dept
Location
28
Site 1
Site 2
Site 3
S2 D2 L2
S1 D1 L1
S3 D3 L3
S1 ? dlt10(Student) S2 ?
d10andd20(Student) S3 ? dgt20(Student) D1
Dept SJ S1 D2 Dept SJ S2
D3 Dept SJ S3 L1 ?
areaeast(Location) L2 ? areawes(Location)
L3 ? areasourth(Location)
Student Dept
Location
ll
29
???????

• ??????????????????????,???????????????????
• R1 R2 Ui (F1i R2)

30
R1
R2
????
R1
R21
R22
f partition
Result
union
?? ??????????????????????
????????? ?? FT(Q, Sj, Ri) ??Ri??,?
Sj????Q???
31

• ???????
• Fragmentation_and_replicate(Q, R, S)
• For ???????????Ri
• For ??????Ri????????Sj
• ?????Sj??????????
• FT(Q, Sj, Ri)
• ????Ri????????????
• Ti max (FT(Q, Sj, Ri))
• ??Rk min (Ti)??????????

j
i
32
R1
R2
????
R1
R2
R11
R21
R2
R22
R12
R2
R13
f partition
Result
union
?? FT(Q, S2, R1) cost(R12 R2)
33
?? ??R1??F11?F12???? F11F1250
R2??F21?F22???? F21 100 F22200 ?
????C00, C11, ????CostJ(x1,
x2)5(x1x2) ???Cost U(x1, x2)
2(x1x2)
34

• ?R1??????, ? ??S1?????
• FT(Q, S1, R1) 2002(100200)5(50300
  )2550
• ??
• FT(Q, S2, R1) 1002(100200)5(50300
  )2450
• ??, ???????R1??????? 2550.

35
?R2??????, ? ??S1????? FT(Q, S1, R2)
502(5050)5(100100)1250 ??
FT(Q, S2, R2) 502(5050)5(200100)1750
??, ???????R2??????? 1750. ??
R1???????????gtR2??????????? ??
??R2????????
36

• ??
• ?????????????, ????????????????????????

37
???????????

• ? ?

R1
? ?
R2
R3
?R1?R2???A?????, ??R1 R2 R3
38
Hash????

• ??Hash????????????????????, ?????, ????????JN??
• ??, ??Hash??
• 1 ?a ???
• 0 ?a ???
• ?R?????, h(a)?1????S1, h(a)?0????S2.
  ??????R????Ro?Re
• R1 R2 (R1o R2o) U (R1e
  R2e)

h(a)

39
Hash????-?

• R1 A R2 B R3
• ?R1?R2?A?????Hash??, R2?R3???B?????Hash??

40
????

• ??????
• ?????
• ??????????
• ???????????R
• ???????
• ???????R
• ?????,?????????
• ???????????(3/2)R
• Hash????
• ??????R
• ????, ?????????
• ???????????????

??????,???????????R1?R2,???????????