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Đề cương CSDLĐPT

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    cng n tp: C sdliu a phng tinLp: D08HTTT1

    Cu 1: Cc loi dliu PT v cch phn loi ? (Kin)Tr li:

    - Cc loi d liu PT bao gm:+ D liu vn bn (c hoc khng c cu trc)+ D liu m thanh

    + D liu nh+ D liu video

    - Mt s cch phn loi d liu:+ Da trn nh dng vt l+ Da trn mi quan h gia cc d liu PT vi chiu thi gian hay khng gian

    Cu 2: Cc c tnh chnh ca dliu PT? (Kin)Tr li:

    - Cc c tnh chnh ca d liu PT gm c:+ Dung lng ln (video, audio)+ D liu video v audio c chiu thi gian nn phi c trnh by tc xc

    nh+ D liu saudio, images, video c biu din bng chui cc gi tr mu ring

    bit, thiu cu trc ngngha my tnh c th tng nhn dng ni dung.

    + Nhiu ng dng PTi hi biu din ng thi nhiu loi d liu PT theochiu thi gian v khng gian ph hp.

    + D liu PT mang nhiu thng tin. Do cn nhiu tham s biu din nidung mt cch ng n

    Cu 3: So snh DBMS vi IR? (on)

    Tr li:

    DBMS IR

    - Mt DBMS cha cc bn ghi ccu trc ng nht:

    + Mi bn ghi c c trng bi ccthuc tnh

    + Gi tr ca thuc tnh miu t r rng

    - Trong IR, cc bn ghi khng ccu trc, khng c thuc tnh cnh:

    + nh ch mc: keywords, indexterms, doc descriptor

    + To t kha v ch mc ng vai tr

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    v y cc bn ghi

    - Trong DBMS, vic truy vn thngtin da trn s trng lp tuyt i giacu truy vn v gi tr cc thuc tnh ca

    bn ghi

    quan trng

    - Trong IR, khng i hi trng lptuyi

    - S truy vn da trn trng khpgia cc tp thut ng

    - S dng cc phng php trnglp xp x hoc tng phn

    - Cng 1 term c thc ngha khc

    Cu 4: Vai tr ca DBMS v IR trong truy vn thng tin PT? (Kin)Tr li:

    Vai tr ca DBMS (H qun trc sd liu) trong truy vn thng tin PT:- Cc h qun trCSDL c pht trin v s dng rng ri i vi d liu c

    cu trc- Trong h qun tr CSDL quan h, thng tin c t chc di dng cc bng

    v quan h. Cc hng ca bng tngng vi cc n v thng tin hoc bn ghi. Ccct tng ng vi cc thuc tnh

    - SQL c s dng thao tc trn CSDL+ V d: create table STUDENT(

    Student_id integer,

    Name varchar(50),

    Address varchar(100))

    - Cc thuc tnh trong h qun tr CSDL quan h c kiu cnh v c kch ccnh. H qun tr CSDL quan h ph hp vi vic x l cc d liu kiu ch s vcc xu k t ngn

    - Loi d liu ln c di bin i c h trtrong h qun tr CSDL quanh l i tng rng hoc nh phn (BLOB)+ V d: create table STUDENT(

    Student_id integer,

    Name varchar(50),

    Address varchar(100),

    Picture BLOB)

    - H qun trCSDL hng i tng+ Kt ni cc c im hng i tng vi CSDL quan h

    + Cc i tng c nh ngha theo kiu hng i tng. Mi i tng chacc thuc tnh v phng thc

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    + V d: Create type Image(

    Private

    Size integer,

    Resolution integer,

    Content float[],

    Public

    )

    create table STUDENT(

    Student_id integer,

    Name varchar(50),

    Address varchar(100),

    Picture IMAGE)

    - BLOBs v cc i tng l mt bc tip cn n x l d liu PT- BLOBs ch lu tr d liu c khi lng ln, cn i tng cha cc thuc

    tnh n gin dn n mt s yu cu x l truy vn d liu PTnh sau:+ Cc cng c tng hoc bn tng trch chn cc ni dung v c trng cha

    trong d liu PT+ Cu trc nh ch mc a chiu xl cc vector c trng+ Cc o tng ng truy vn thng tin PT thay v s dng trng lp chnh

    xc

    + Cc h thng con lu tr d liu kch cln, bng tn rng, thi gian thc+ Giao din ngi dng cho php to cu truy vn linh hot trn cc loi d liu

    PT khc nhau, biu din d liu PT.

    Vai tr ca IR trong truy vn thng tin PT- IR tp trung vo truy vn ti liu vn bn- Cc k thut IR ng vai tr quan trng trong qun l thng tin PT bi:+ Tn ti mt lng ln cc ti liu vn bn cc dng t chc, v dnh th vin.

    + Vn bn c dng ch gii cc loi d liu PT khc- Tuy nhin, vic dng cc k thut IR trong xl thng tin PT c hn ch:+ Vic ch gii l qu trnh th cng, tn thi gian+ Vic ch gii l khng y v mang tnh ch quan+ Cc k thut IR khng th x l cc cu truy vn dng khc vn bn+ Mt vi c im PT kh m t bng vn bn (kt cu nh, hnh th i

    tng..)

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    Cu 5: Cc kin trc h thng CSDL PT?(Ngha)

    Tr li:

    a. Kin trc cp lng- Th no l kin trc cp lng+ H qun tr CSDL l 1 h thng gm 1 CSDL v cc thao tc trn CSDL ,

    c thit k trn nn tng phn cng, phn mm vi mt kin trc nht nh+ H qun tr CSDL y qun l d liu metadata+ Thnh phn qun l tp tin a phng tin, qun l d liu a phng tin

    + Module tch hp h qun tr CSDL v thnh phn qun l tp tin a phng tin

    - u im: Tn dng cc h thng qun l tp tin a phng tin khc nhau qun l d liu

    b. Kin trc cp cht- Kin trc cp cht+ H qun tr CSDL y qun l d liu a phng tin v metadata+ H qun tr CSDL l mt MM-DBMS

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    - u im: Cc chc nng ca DBMS c th c p dng trn CSDL aphng tin

    + Qun l truy vn+ Qun l giao dch

    + Qun l lu tr+ Qun l bo mt ton vn

    c. Kin trc lc - Lc l metadata m t d

    liu dpt trong CSDL- M hnh 3 mc lc - Lc ngoi nh ngha cc

    cch nhn ca ngi dng i vi CSDL

    (video view, audio view)

    - Lc khi nim c xydng da trn cc m hnh d liu

    - Lc trong: cu trc d liubn trong

    - Mi lc c cc cch biudin khc nhau

    - Mappings thc hin chuyn it biu din ny sang biu din khc

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    d. Kin trc chc nng

    e. Kin trc h thng mrng

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    f. Kin trc phn tn- Cch m cc i tng c phn tn v kt hp+ Truy vn

    + Giao dch+ Metadata

    + Bo mt+ Ton vn d liu

    g. Kin trc lin ng- Client/server (CORBA)- Ba tng (three tier)- Hng thnh phn

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    h. Kin trc siu phng tin: h trduyt CSDL theo cc lin kt

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    Cu 6: Dliu meta cho CSDL a phng tin? (Phng)

    Tr li:

    1. nh ngha Metadata- L dng d liu m t v d liu. Trong c sd liu, metadata l cc dngbiu din khc nhau ca cc i tng trong c sd liu. Trong c sd liu quan

    h, metadata l cc nh ngha ca bng, ct, c sd liu, view v nhiu i tngkhc. Trong kho d liu, metadata l dng nh ngha d liu nh: bng, ct, mt boco, cc lut doanh nghip hay nhng quy tc bin i. Metadata bao qut tt c cc

    phng tin ca kho d liu.- Metadata phi cha nhng thng tin: cu trc ca d liu, thut ton s dng

    tng hp d liu, nh xxc nh stng ng d liu tmi trng tc nghipsang kho d liu

    2. Vai tr Metadata- Thng tin metadata c cung cp cho php ngi dng cui hiu r hn bn

    cht v d liu m hang c v quyt nh s dng mt cch ng n v ph hpd liu.

    - Cu trc v ni dung d liu bao gm mt s loi thng tin c bn: Thng tinm t v bn thn d liu metadata; thng tin v d liu m metadata m t; thng tinv c nhn, t chc lin quan n d liu metadata v d liu

    3. Cc loi metadata- Metadata cho cc loi phng tin khc nhau- c trng bng mi quan h vi ni dung d liu a phng tin- Metadata c thc trch chn trc tip t d liu a phng tin Metadata cho d liu vn bn- Cha ng thng tin v d liu vn bn- Metadata c lp ni dung:+ Loi d liu vn bn+ S trang

    + nh dng+ Schng, s paragraph mi chng- Metadata ph thuc ni dung: Ni dung cu chuyn, tkha, tiu , tm tt- SGML (standard generalized markup language), XML c s dng gn th

    cho cc loi d liu vn bn c th trch chn- Cc th c thc lu trong DBs- D liu text c thc ch gii Metadata cho d liu nh-

    S dng d liu text m tnh- Metadata c thc lu trong DBs

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    - Metadata c lp/ph thuc ni dung- V d: Bc nh X m ti dng vi rng c v nhng ngi nh trn bi bin Metadata cho d liu m thanh- M hnh ha cho d liu m thanh- Gn th metadata- Trch chn t kha trong th- D liu m thanh c thc ch gii- Metadata c lp/ph thuc ni dung Metadata cho d liu video- M hnh ha cho d liu video- Gn th metadata- Trch chn t kha trong th- D liu video c thc ch gii- Metadata c lp/ph thuc ni dung Metadata cho d liu kt hp- Metadata dng ng b hin th cc loi phng tin4. Cc kha cnh lin quan n Metadata- Ontology cho d liu a phng tin+ Ontology l c t v s khi nim ha+ Dng biu din tri thc chung cho qu trnh cng tc- Ch gii+ Qun l ch gii: trch chn, truy vn, cp nht, tng quan gia cc ch gii v

    d liu a phng tin- Cht lng dch v v ngun gc d liu+ chnh xch ca d liu+ Ngun gc ca d liu

    5. Qun l Metadata- Truy vn- Cp nht- Bo mt- Trch chn

    Cu 7: K thut nh ch mc cho cc loi dliu khc nhau? (. Giang)

    Tr li:

    - D liu vn bn: da trn t kha. Mt vn bn lun mang cng lc nhiu yut, do vy phi chn mt tkha c ngha rng nhng phi t k t. Khng nn chn

    t kha qu di hay qu ngn. La chn t kha cn phi tr li c cu hi: vn bn

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    thuc loi no? i tng hng n l ai? Ngi dng dng loi cng cno tmkim?

    - D liu nh: da trn t kha, nh- D liu video: da trn t kha, cc nh trch trn tnh- Audio: t kha- Ch gii.

    Cu 8: Cc k thut lu trtrong c sdliu a phng tin? (Cc)

    Tr li:

    - Dng mng cc a r tin- Kin trc lu tr phn cp+ Dng bng tv a quan lu tr di hn, a tlu on bt u ca phng

    tin (trban u thp)+ Di chuyn files tbng tra a t khi c yu cu (trban u di gii php

    da trn mu s dng, tn s s dng)- Lu tr d liu trn thit b+ Cc tp tin c phn thnh cc blocks+ Cc blocks c lu a theo cc phng php khc nhau

    Lu lin tc: Cc block ca file nh v lin tip trn cc block ca a.

    u im:dci tNhc im: Tn thi gian khi chn v xa, phn mnh aThch hp cho ng dng ghi mt ln, c nhiu ln.

    Lu c rng buc: Tng block ca file cha con tr tr ti block k tipu im: d mrng fileNhc im: c file chm

    Lu ri rcDanh sch lin kt, FAT, I-nodes

    - Lu tr d liu trn mng a.+ Lu ton bfile a phng tin trn mt a+ Lu file trn cc a khc nhau

    + Lu ton bfile a phng tin trn mt a+ Lu ton bfile a phng tin trn mt a

    + Lu file trn cc a khc nhau+ Cc k thut phn tn cc blocks trn cc a:

    Data Striping: Blocks c t chc thnh cc nhm truy cp, cc a ctruy cp ng b

    Data interleaving: Cc a khng c truy cp ng b

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    Mong mun c kch thc ca blocks bng vi kch thc ca cc n v dliu phng tin logic

    - iu a v iu khin tip nhn+ Thit blu tr cn truyn d liu bng vi tc phng tin c biu th pha

    client

    + Hot ng a l khng tt nh nn cn c c chiu a duy tr