TAP CHi CONG THIfONG
ifNG DUNG CONG NGHE THONG TIN TRONG QUAN LY Cd sd D 0 LIEU
• NGUYEN THI VIET HA
T 6 M TAT:
Ngay nay, sff bung nd vd phdt ttidn thdng tin vd truydn thdng da ddp ffng hau hd't cdc Hnh vffc cQa ddi sd'ng xa hdi, dffdi mpi quy md tff nhd dd'n Idn. Di ddi vdi vide thffc Men, sff dung quan ly va phdt ti'ie'n cdng nghd thdng tin Id qudn ly cd sd dff lieu, mpi thdng tin c^n quan ly tren mdy tinh theo bd't cff quy tnnh cu the ndo cung deu phdi dffde the hien bang cdc dff lieu ghi tren dang tai nao dd. Chinh vi vdy, quan ly thdng tin tffc la quan ly dff lidu. Bai viet ndy ban ve ffng dung cdng nghd thdng tm hrong qudn ly cd sd dff lieu.
Tff khda: Cd s6 dff lieu, cdng nghe thdng tin, phu thudc hdm, ffng dung.
1. Dgt v3'n de
Trong ffng dung nhffng thanh tifu cua cdng nghe thdng tin vao cdc linh vffc cua ddi sd'ng xa hdi thi vide quan ly cd sd dff lieu (CSDL), chud'n hda CSDL phu Ihudc ham cd y nghTa rd't quan trpng va dam tinh khoa hpc cdng nghe, la cdng eu dd md ta thifc tidn va phuc vu eho vide ehuan hda cdc he CSDL.
Dd'i tu'dng lim hid'u vd nghien cffu eua de tdi:
Nghidn cffu cd sd ly diuyd't cae phu thudc ham, cae tffdng quan giffa cae thudc tinh cua mot quan he. Iff dd hid'u du'dc mdt phu thudc ham ehi ra rang gid tri cua mot thudc tinh dffdc xdc dmh duy nhd't bdi mdt so'cae thudc tinh khde.
Lfng dung phu thudc hdm la chuan hda dff lieu trong md hinh dff lieu quan hd, phu thudc ham la mdt cdng eu diing de bidu didn mdi each hinh Ihffe cdc rang budc toan ven, cd thd ndi Id mdt cdng cffc ky quan trpng, gan chdt vdi ly thuye't thid't kd' CSDL.
Phu thudc hdm la npi dung cd y nghTa he't sffc quan trpng trong qua trinh thie't kd', vi rang ehi khi cdc quan he dffdc chud'n hda, cdc di thffdng xud't hien trong qud tnnh thao tdc dff lieu mdi dffde loai bd. Nhd cd nhffng md ta phu thudc ham ma he
quan Iri CSDL cd the quan ly td't dffdc cha't Iffdng dff lieu. Do dd, y nghia khoa hpc cua de tdi la diing phu thudc ham de md ta thffc tien va phuc vu cho vide chud'n hda cdc he CSDL.
Phu thudc ham ddng vai Ird quan trpng trong viec md ta thd' gidi thffc, phan dnh cdc md'i rang bude trong quan ly CSDL, cd rd't nhieu ffng dung trong cdc linh vffe quan ly (CSDL), td'i ffu hda truy van...
Phffdng phdp nghidn cffu: Trong bdi vid't sil dung phu'dng phdp thu thdp, phan tich va tdng hdp cdc tdi heu thdng tin c6 lien quan de'n de tai. Trdn cd sd nghien cffu ve phu thudc hdm xdy dffng bai todn thffc nghiem de chffng minh nhffng nghien cffu ve ly thuyet.
2. Cac kie'n thffc cd ban vl crf sof dff li^u 2.1. Khdi qudt ve mo hinh dd lieu quan ftf CSDL la mot trong nhffng linh vffe dffde tap trung nghien cffu vd phdt trid'n cua cdng nghe thdng tin, nham giai quye't cdc bai toan quan 1^, tim kie'm thdng tin trong nhffng he thd'ng Idn, da dang, phffe tap. Cung vdi sff ffng dung manh me cdng nghd thdng tin vdo ddi sd'ng xa hpi, kinh td, qud'c phdng... Vide nghidn cffu CSDL da va dang phat trien ngdy cang phong phu va hoan thien. TCf
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QUAN TR!-QUAN LV
nhffng nam 70, md hinh dff lieu quan he (Relational Data Model) do E.F.Codd difa ra ca'u true hoan chinh da tao nen ed sd loan hoc cho cdc vd'n de nghien cffu li thuye't CSDL. Vdi nhffng ffu didm ve ca'u true ddn gian vd kha ndng hinh thffc hda phong phu, CSDL quan he dd dang md phdng cdc he thd'ng thdng tin da dang trong thffc tien, tao dieu kien lifu trff thdng tin tiet kiem, cd tinh ddc lap dff lieu cao, de sffa dd'i, bd sung cung nhif khai thdc dff lieu. Mat khde, vide cdi dat CSDL quan he dffa lai hidu qua cao vd Idm cho CSDL quan he chie'm ffu thd'trdn thi tnfdng.
Vide nghien cffu CSDL & Viet Nam vd trdn thd'gidi lap trung vao mdtsd md hinh: md hinh dff lieu quan he, md hinh dff lieu mang, md hinh dff lieu hffdng dd'i tifdng. Ddy Id cdng cu td't cho ngffdi ldp trinh, giup hp xay difng ndn cac ffng dung quan ly da dang. Song viec thie't ke CSDL theo md hinh dff lieu quan he lai la mot viec khac, ddi hdi ngu'di ldp trinh phai ed hieu bid't thd'u ddo ve nhffng tu'dng quan y nghia, hay cdc phu thudc ham eua nhffng dff lieu ban dau, cdc cdch tid'p cdn dd thid't kd' CSDL. Nghien cffu chud'n hda dff lidu trong qud trinh thid't kd' cung cd y nghia rd't quan trpng, vi chi khi cdc quan he du'dc chuan hda Ihi eae di thffdng xua't hidn trong qud trinh thao tdc dff lidu mdi du'dc loai bd.
2.2. Phu thuoc hdm, khda, he tien de Armstrong
Trong phdn ndy, ehung ta se xem xdt nhffng khdi mem cd ban nhd't cua md hinh dff lieu quan hd:
Dinh nghia Phu thudc hdm tren quan he Cho R = {aj, aj, • .aU]} Id tdp hdp cac thudc tinh, r = {h^, hj, ., h^^} Id mdt quan he tren R, va A, B la cdc tap con cua R (A, B c R).
Khi dd ehung ta ndi A la xdc dinh cho B hay B phu thudc ham vao A trong r. Ky hidu Id:
A -^— > B ndu: f r
(Vhi, hjGr) ((VaeA)( hi(a) = hj (a)) ^ (VbeB) (hi(b) = hi(b))
DdlF, : [{A,B):A,B^R,A^>B } Khi dd, Fj dffdc gpi la hp day du cdc phu thudc hdm effa quan he r.
Nhdn xet: Khdi nidm phu ihudc hdm mieu ta mdt loai rang bupe (phu IhuOc dff lieu) xay ra iff nhidn nhd't giffa cac tdp thudc tfnh. Dii hidn nay da cd nhieu loai phu thudc dff lieu dffdc nghien cffu.
xong ve cd ban cdc he quan iri CSDL Idn thu'dng sff dung phu thudc hdm.
Dinh nghia He tien de Amstrong
Gia sff R la tdp cdc thudc tinh va ky hidu P (R) la lap cdc tap con cua R.
Cho Y c P(R) X P(R). Chung la ndi Y Id mdt hp f trdn R ne'u dd'i vdi moi A, B, C, D c R:
(1). (A,A) e Y
(2). (A,B) G Y, (B, C) e Y Ihi (A, C) e Y (3). (A,B) G Y, A c C, D c B thi (C,D) e Y (4). (A,B) e Y, (CD) G Y thi (A uC, BuD) G Y Rd rang Fj. la mdt hp f ti-en R.
Armstrong da chffng minh mdt ke't qua rd't quan trpng nhff sau: Neu Y Id mdt hp f bd't ky thi tdn tai mdt quan he r trdn R sao cho F^ - Y.
Ket qua nay cung vdi dinh nghia cua phu thudc ham chffng td rang hd tien de Armstrong la dung dan va day du. Cd nghia la 4 tinh chd't trdn dung la cac dac trifng cua hp cdc phu thudc ham.
Armstrong da dffa ra he tien de (cdn gpi Id hd ludt suy dan Armstrong hay c^c tinh chd't cua phu thudc ham) vdo nam 1974 nhff sau:
• Ludt phan xa: Nd'u Y c X thi X -» Y
• Ludt tdng trifdng: Neu X ^ Y thi XZ ^- YZ
• Luat bac cau: Neu X -> Y va Y -^ Z thi X ^ Z
Ngffdi ta dd chffng minh rang, he tien de Armstrong la diing ddn va dly du thdng qua 3 bd dd.
Bd de 1: He tien de Armstrong la dung, nghTa la: vdi F la tdp phu thudc ham dung trdn quan he R ne'u X —> Y la mot phu thudc ham dffdc bieu didn logic Iff F nhd hd tidn dd Armstrong thi X —> Y cung dung trdn he R.
Bo de 2: Tff he tidn de Armstrong suy ra mdt sd' lual bd xung sau ddy:
a. Ludt hdp (ludt tich hdp):
Nd'u X ^- Y va X -^ Z thi X -> YZ b. Lual tffa bac dn (bac cau gia):
Nd'u X ^ Y vd WY ->Z thi XW -> Z e. Ludt tdch (linh phdn rd):
Neu X -> Y va Z c Y thi X ^ Z Bo de 1.3: X —> Y dffdc suy didn logic tff F nhd he tidn de Armstrong nd'u va nd'u Y e X-i- p
2.3. Mdi quan he gida quan he Armstrong vd bMc do quan M
Viec xdy dffng quan he ArmsQ-ong cua mdt Iffdc 6.6 quan he cho trffde vd ngffdc lai, tff quan he cho tnfdc tien hdnh xay dffng mdt Iffdc dd quan hd sao cho quan he cho trffde la quan hd Armtrong eua nd
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TAP CHi CUNG THIflfNG
cd vai trd rd't quan trgng trong vide phdn tich ca'u true logic cua md hinh dff lieu quan he, ca trong thie't ke' cung nhff trong ffng dung. Trong phan nay ta se tie'n hanh xdy dffng 2 thuat toan dd' giai quye't hai bai loan trdn.
2.3.1. Xdy dung thudt todn tim quan he Armstrong dua tren LDQH
Nhff da trinh bay trong dmh nghia 2.2, lap phan khda ddng vai trd rat quan trpng trong qua trinh nghien cffu ca'u true logic eua eac hp phu thudc ham, khda, dang chud'n, quan he Armtrong. Di/a trdn dinh nghia nay, ta xdy dffng thudt todn tim tap eac phan khda nhff sau:
+ Thuat todn tim tap phan khda:
Vao: K = {B,, Bj .., B^) la he khda Sperner ti-en R
Ra: Tdp phan khda K-' Phu'dng phdp
Bffdc l : D a l K | = {R-{a}:a e B,}. Hid'nnhidn K, = {Bi}'-
Bffde^-l-7:(a<m). Gia thie't rang Kq:KqU{Xi, -..X,q}, d day Xq, ... X,q chffa B^^, va F^ = {A e
Doi vdi moi i (i = 1, L) tim cac plian khoa ciia {^q+|} ^ ^ " XjtiiOng tLf nhifK,. Ky hieucliLing la A,,,..., A„.
Dat Kq+i = Fq u {Ap';A i F^j Iteo theo Ap' c A, l < i < t , , l < p < r , )
Cuo'i ciing dat K' = K^
2.3.2. Xay dung thudt todn tim luac do quan he dua trin quan he Armstrong
+ ThuSt toan 1,12: Tim mot khoa toi thieu tiif tap cac phan khoa:
Vao: Cho K va H la 2 he Sperner, va C = {b,...,b„) c R sao cho H"' = K va BB e K:B c C.
Ra: D s H, PhtfOng phap:
Bttac l:DatT(0) = C Birdci+ l : D a t T = T„, , - b , ^
'li+D ^ f Tneu VB s K k h o n g c o T c B I T,„ ngi T(,) ngt/oc lai
Cuo'i cung dat D = T(m) Bode 1 8
Neu K la tap cdc phan khoa thi T(m) e H, Biide 1.9
Cho H la mot he Sperner tren R va H ' = (B,, ,.,B^ I la tap cac phan khoa ciia H, T c H. Khi do, T c H, T ^ 0 neu va cht neu ton tai B e R sao cho B E T - ' . B e B , (Vi: 1 <i<m).
Tren cosdciia bd de 1.9 va thuat toan 1,12, ta
xay dirng thuat toan tim tSp cac khoa tdi thieu ttf tap cac phan khoa nhif sau:
+ ThuSt toan 1.13: Tim tap cac khoa tdi thieu til tap cac phan khoa:
Vao: Cho K = {B£, ..., Bj.} la mot he Sperner tren R
Ra: H ma H ' =K Phifdng phap:
Budc 1: ap dung thuat toan 1.14 d tren de tinh Ai,dfitK| = Al
Bit(Sci+/:NeucdB s Kf'sao cho B c Bj (VJ:
1< j < k), thi bdi thuat loan 1.12 tinh ra Ai+1, d day A „ | s H, Ai^., c B. Dat Ki+, = Kl u Ai^.,
Trong trudng hop ngUOc lai dat H = K,.
Bode 1.10
Cho F la mot ho f trdn R, a E R Dat L((A) = (a E R: (A, | a ) ) E F ) . Z F = {A:L^A) = A). Ro rang:
R s ZF. A, B E Z F ^ A n B E Zp. Ky hieu Nf la he sinh toi thieu ciia Zp
Dat U, = {AENF:a « A, 3 B E NF :a «!B,A cB]
Khi dd M, = MAX(F,a), d day MAX (F,a) = |A c R: A la mot tap cue dai khong rdng ma (A, {a|)
« F )
Tren cd sd ciia thuSt loan 1.13 va bd de 1.10 tr6n, ta xay dUng dUdc thuat toan thii 2.
+ Thuat toan 1.14: Thuat toan tim mot lUdc 66 quan he diia tren mot quan he Armstrong
Vao: r la quan he tren R Ra: <R,F> ma F* = F,.
PhUdng phap:
Budc 1: Ta r tinh he bang nhau E, Budc 2: DatN,= {A eE,:A5en|BE E,: AcB)) Budc 3: Vdi mdi a E R xiiy dUngN^ = [AE N^:
a « A, 3B EN,:agB, A c B ) . Sau ddap dung thuat loan 1.13 xdy dUng ho H^iH^' = N^)
Budc 4: Xay dUng s =<R,F> d day F=( A->(a):
Va E R, A E H J , A # | a ) | Bode].11 V. = F*
Vidu 1.7: Cho r la mot quan he tren RnhU sau:
a b e d
6 6 6 0 0 2 0 2 0 0 0 0 0 0 0 3 4 4 0 0 5 0 5 6 1 0 0 0
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QUAN TRj-DUAN IV
Ap dung thuat loan trgn ta tinh:
E,= ((a,b,c), {b,c,d), {a,c|, (b,c) ic,d|, (b), ( d ) , 0 1
N,= ((a,b,cl, (b,c,d), (a.c), {c,d), (b), (d)) N, = {(b,c,d))
Ni,= {{a,c),{c,d)) Nc={{b),{d)) Nd={(a,b,c))
Ta cd: Ha = {a}
Hi,= {(bl,(a,d)) H,= {{a),{b,d),[c)l Hd={d)
Ta xay dUng dUdc s = <R, F> nhu sau:
R={a,b,c,d)
F = ( l a , d ) - * ( b ) , { a ) ^ ( c l , ( b , d } ^ { c ) ) Nhdn xet ve 2 thudt todn trdn:
Trong tiffdng hdp tdi nhat:
Dp phffe lap thdi gian eho viec lim kid'm mdt quan he Armstrong cua mdt lifdc dd quan hd cho trifdc la ham mu theo so' Iffdng cua cdc thudc tinh.
Dp phffe lap thdi gian eho vide tim kid'm mdt Iffde do quan he s = <R,F> tff mdt quan hd r cho trifdc sao cho F,- = F+ la hdm sd' mu theo so' Iffdng cdc thudc linh.
Day la hai thuat loan thid't ke' ddng vai trd quan trpng trong md hinh dff lidu quan he. Thudt toan thff nhd't md ta each thffc di lim hinh dang cua mdi file dff lieu dffa ti-en mdi lifdc dd quan hd cho trffde.
Trong khi do, thudt todn thff hai cho ta cdch thffc rut ra cdc phu thudc hdm xua't phat iff mdt quan he.
Dd la mot loai rang budc dff lidu phd thdng nhd't.
Nd'u cac phu Ihude ham cung vdi quy luat suy didn Id he tidn dd Armstrong cd the hieu la eac tri thffc till tiiuat thff hai chinh la each Ihffe phdt hidn cdc tn Ihffe dd tff dff lidu.
3. Mdt sd' phep toan xu" ly bang Ngdn ngff xff ly dff lieu la mdi ph^n quan trpng trong cdc he quan tii CSDL. Ngay tff nam 1970, E.F.Codd da dffa ra 2 ngdn ngff xff ly dff lidu chinh, do la ngdn ngff dai sd' quan he vd ngdn ngff tinh todn quan he. Hlu hdt ngdn ngff xff ly eua cdc he quan tri CSDL Idn hien nay deu chffa ngdn ngff dai sd quan hd.
Ngdn ngff dai sd' quan he du'dc xem nhif la ed sd eua mdt ngdn ngff bdc cao de thao tdc trdn quan he. Ngdn ngff nay bao gdm 2 nhdm phep todn: cac phep todn tdp hdp (phep hdp, phep giao, phep trff vd mdt dang cua tich De cac), va c^c phep quan he ddc bidt (phep chpn, phep chid'u, phep kd't nd'i, phep chia).
Trffde khi xet eae phep toan, chiing ta cung gia thie't rdng r la quan he tren tap Ihudc tinh R ={ai,a2,...,a„}, d day ludn gia thid't rang quan he r Id tap hffu han cdc bd. Ta cd cdc phep todn quan he sau:
3.1. Phep chieu
Cho hifde mdt lifdc do quan he R (Aj, A2,.., Aj,), X e R, r(R):
nAr)={t[X]\t^r]
Ki hieu: fX^,^ ^, ^ ^„{r). A, Id cdc thudc tinh chie'u - Phep chid'u dung dd' bo bdt cdc thudc tinh khdng quan tdm tff quan he ban dau.
- Ket qua Id mot quan he ed sd' col la tap Ihudc linh chid'u X, so'ddng la sd'ddng trong r cd loai bd sif trirng lap.
- Ne'u X cd chffa khda cua r thi khdng can loai bd sff trung lap dff lieu.
3.2. Phep chon
Phep chpn cho phep Iffa chpn nhffng ban ghi thda man dieu kidn nao dd de dffa vao quan hd kd't qua. Didu kidn chinh Id mdt bie'u thffc logic cho kd't qua hodc la True hoac la False khi danh gia tren eae bp gid Iri cua quan hd ngudn, nd Id td hdp cua cdc bid'u thffc logic cd sd. Mdi bieu thffc cd sd chffa mdt phep so sanh trong bidu thffc logic la <, =, >, <, >, i^ va cdc phep logic Id A (vd ) V (hodc), -| (khdng).
Cho Iffdc do quan he R(A,, Aj,..., A„), r(R):
(j{r, F)- [t\t rva t thda F), Fid bieu thffc eho bid't didu kidn chpn.
Ki hieu: ag (r)
- Phep chpn dffdc dung de trich chpn eac ddng thda dieu kien chpn F tff quan hd ban dau.
- Kd't qua la mdt quan he ed so' edl bang so edl cua r, cd sd ddng la sd' ddng trong r thda F.
3.3. Phep hap KI hidu: u
Gia sff r vd s la 2 quan he n cdt. r vd s Id 2 quan he kha hdp. Bieu didn hinh thffc cua phep hdp:
r u s ^ {tl(t e r) w ( t e s))
Hai quan he la kha hdp ne'u chung cd cung so' thudc tinh va cae thudc tinh tffdng ffng ciing mien gia tri.
Ke't qua Id mdt quan he cd cac thudc tinh la cdc thudc linh cua quan he r, so' bd Id sd' bd cua hai quan he cd loai bd sff trung lap.
3.4. Phep giao
Giao cua 2 quan hd r va s Id tdp cdc bp thudc ca 2 quan he r vd s. Dieu kidn cua phep giao Id 2 quan he r va s phai ciing Iffdc dd.
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Bidu dien hinh thffc cua phep giao:
r n s = { t l ( t G r ) n ( t E s)(
Ke'l qud la mdi quan he ed cdc thudc tinh la cae thudc tinh cua quan he r, gdm eac bd xua't hien d ca 2 quan he.
3.5. Phep trd
Hidu cua 2 quan he r vd s Id tap hdp eae bd thudc r nhffng khdng thudc s. Dieu kidn cua phep hieu Id 2 quan he r vd s phai ciing Iffdc dd.
Bieu dien hinh thffc cua phep hieu:
r- s = it 11 e r o t gs}
Ke't qua la mdt quan he ed eae Ihudc tinh la eac thudc tinh cua quan he r, gdm cac bd xud't hidn d r ma khdng cd d s.
3.6. Tich De cdc cua hai quan he Gpi r la quan he xdc dmh tren lap thudc tinh [A|, A,, , Aj,} va s la quan he xac dinh trdn lap thudc tinh (Bj, B2,..., B^,). Tich De cdc cua r va s Id tap (n+m) bd vdi n thdnh phan dau cd dang mot bd thudc r va m thdnh phan sau ed dang mdt bd thudc s.
Trong phep tinh De cae, 2 quan he ed the khdng cung Iffdc do.
Bie'u didn hinh thffc eua phep tich De cdc:
r x s = {(t,u) [ t G r n u es}
Nhdn xel: Vi ta cd It! = n vd lu! - m nen suy ra I(t,u)l = n X m thdnh phan.
3.7. Phep chia hai quan hf
Gpi r Id quan hd n - ngdi va s la quan he m - ngdi (n > m vd s ^ 0 ) . Phep chia r cho s Id tap eua ta't ca (n - m) bd t sao cho vdi mpi bd UE S thi bd (t,u) er:
r-^s = [u = (A|, Al,..., Ap)l Vv es: (u,v) e r | Vdi dieu kidn cua phep chia la: s phai Id tap eon thffc sff cua r, tffc la:
{Ap„.Ap,2,....A^}e{A„A2,....AJ 3.8. Phep ket ndi
Phep ke'l nd'i cua quan he r dd'i vdi tap thudc tinh {A|, A2,-., A„| va quan he sdd'i vdi tap thudc tinh {B|, B2, Bn,} theo dieu kien A 9 B dffdc dinh nghia hinh thffc nhif sau:
r ® s = {(t,u)lle rva u E s va t[Al eu[Bl}
AeB
Trong dd 0 la mdt trong eae phep so sanh: <, =,
>. <, >, ^
Td't nhien, d day gia thid't rdng mdi gid trj cua cdt r[A] cd thd' so sdnh dffde (qua phep 6) vdi mdi gia Iri ciia cots [B].
Ta ciing cd the' dinh nghTa phep kd't nd'i thdng
qua phep chon theo dieu kidn 11, nhff sau:
r ® s = (rxs; Q
4. Xay dffng chffdng tnnh iJng dung 4.1. Gidi thieu chdffng trinh
CSDL la mdt trong nhffng chuyen ngdnh quan trpng bac nhd't trong ITnh vffc cdng nghe thdng tin.
Hau he't, CSDL dffdc van dung dd' xay dffng nhffng phan mem nham ddp ffng cae ydu cau trong thffc te'. Tuy nhien, nhffng phan mem dffdc xdy dffng de hd trd vide thie't ke' va kidm tra tinh chd't cua CSDL la chffa nhieu.
De thffc nghidm ffng dung ve phu thudc ham, trinh bay md phdng chffdng trinh ffng dung cua phu thudc ham la chuan hda dff lieu trong md hinh dff lidu quan he, vdi mdt tap thudc tinh trong Iffdc dd quan he, chffdng Irinh se thffc hidn kidm tra thudc linh cd phai la khda hay khdng; tim bao ddng cua tdp thudc tinh; tim td't ca cdc khoa vd sieu khda;
kiem tra cdc dang chuan cua Iffdc dd quan he.
Cai dat chffdng trinh ffng dung nham muc dich md phdng cac ke't qud nghien cffu difdc cua hpc vien. Chffdng trinh cd giao dien ddn gian, de sij dung, dd hidu va dffdc vie't bang ngdn ngff Visual Basic 2005, mdt ngdn ngff kha phd bid'n, dl hpc, di hieu, hffdng dd'i Iffdng... va cho phep tao giao dien nhanh, dd dang.
4.2. Cdc chdc ndng cua chddng trinh Cdc chffc ndng chinh cua chffdng tiinh bao gdm:
- Menu Chuan bi dff lieu gdm: tao, lifu, md va xda tap thudc tinh.
- Menu Chuan bi phu Ihudc hdm gdm: tao, Iffu, md va xda ldp PTH.
- Menu Cdc thudt toan gdm. kiem tra Ihupc tinh cd phai la khda hay khdng, tim bao ddng eua tap thudc tinh, tim td't ca eae khda vd sieu khda, kiem tra quan hd ed id BCNF va thodt khdi chffdng tiinh.
5. Ke't luSn va hiifdrng phat tri^n Vdi muc dich la hpc tdp va nghidn cffu ve phu thudc ham, trong nghien cffu nay, tdc gia da trinh bay nhffng ke'l qua tim hidu eua minh ve: Cdc kien thffc ed ban ve cdsd dff lidu; Trinh bay chi tie't cdc dang chuan va eac thudt loan cd lien quan; Tiinh bay mot so' phep toan xff ly bang; Xdy dffng chifdng trinh ffng dung md phdng vd'n de ly thuye't nghidn cffu.
Hffdng phdt trie'n tidp eua de tdi: Phdt trien phu thudc dff lidu eac loai; Thid't ke vd td chffc kho dff lieu; Cung phdt trien vdi cac phffdng phap khai phd dff lieu •
148 So 21 -Thang 11/2019
QUANTRj-QUANLY
TAI LIEU THAM KHAO:
Tie'ng Vipt
1. Vd Ddc Thi (1997). Ca sd dd lieu-Kien thdc vd thUc hdnh, Nhd xud't bdn Thdng ke, Hd Npi.
2. Vd Ddc Thi (1999), Thudt todn trong tin hpc. Nhd xud't bdn Khoa hpc vd Ky thudt, Hd Not.
3. Le Tien Vuang (1996), Nhdp mon ca sd dd lieu quan he, Nhd xud't bdn Khoa hpc vd Ky thudt, Hd Not.
4. Mot sd kit qud nghien cdu ciia tdc gid Vu Ddc Thi - Vien Cdng nghe Thong tin.
5. Vd Ddc Thi (2010). Ca sd dCt lieu ndng cao. Nhd xudt bdn Dai hoc Thdi Nguyen.
6. Date C.J (1986), Nhdp mdn cdc he ca sd dd lieu. Ho Thudn. Nguyen Xuan Huy dich. Nhd xudt bdn Thdng ke, Hd Npi.
Tiing Anh
7. Demetrovics J. Thi V.D (1988), Some results about functional dependencies. Acta Cybemetical 8. 3, 273-278.
8. Demetrovics J, Thi V.D (1988). Relations and mlnumal keys. Acta Cybemetical 8, 3. 279-285.
9. Demetrovics J, Thi V.D (1994), Normal Forms and Minimal Keys in the Relational Datamodel, Acta Cybemetical Vol.11. 3, 205-215.
10. Demetrovics J, Thi V.D (1996), Some results about normal forms for functional dependency in the relational datamodel. Discrete Aplied Mathematics 69, 61-74.
Ngay nhan bai: 20/10/2019
Ngay phan bi^n danh gia va siVa chffa: 30/10/2019 Ngay cha'p nh^n dang bai: 10/11/2019 Thong tin tdc gid:
NGUYEN THI VIET H A
Trifflfng khoa Khoa hpc cd ban - Trffdng Cao dang Cdng nghe va Kinh te' Cdng nghidp
APPLICATION OF INFORMATION TECHNOLOGY IN DATABASE MANAGEMENT
• NGUYEN THI VIET HA Dean of Faculty of Basic Sciences Industrial Economic - Technology College ABSTRACT:
Nowadays, the explosion and development of information and communication have covered almost all areas of social life. Along with the implementation and management of information technology, database management plays an important role in documenting every specific procedure. In other word, information management is data management.
This article discusses information technology applications in database management.
Keywords: Database, information technology, functional dependencies, applications.
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