🔙 Quay lại trang tải sách pdf ebook Các hệ thống thông tin quản lý Ebooks Nhóm Zalo DOAN PHAN TAN CAC HE/THONG TRUONG DAI HOC VAN HOA HA NOI ■ ■ ■ HA NOI - 2004 P(JS. TS. D()An PHAN TAN CAC HE THONG THONG tin q uAn ly (MANAGEMENT INFORMATION SYSTEMS) GIAO TRINH DANH CHO SINH VIEN NG AN H QUAN LY VAN HO A TRUING DAI HOC VAN HOA HA NC)I - 2004 L()I NOI DAU Ngay nay sir quan tarn doi voi thong tin va tri thurc nhu mot nguon lire cua m6i ca nhan, to chuc va xa hoi tang nhanh gap boi so voi bat cu thoi ky nao trong lich su. Cac he thong thong tin va cac he thong thong tin quan ly tro thanh bo phan hiru ca cua bat cu he thong to chuc xa hoi nao. No dem lai hieu qua cho hoat dong quan ly xa hoi, la cong cu chu yeu de nang cao hieu qua cua dau tu, mo rong kha nang tiep thu tri thutc va huong thu van hoa, nang cao chat luong dich vu doi voi moi ngudi. Giao trinh "Cac he thong thong tin quan ly" co muc dfch cung cap cho sinh vien nganh Quan ly van hoa nhung kien thuc co ban va he thong v t cac he thong thong tin va cac he thong thong tin quan ly dua tren may tmh, nhu cac he thong thong tin xir ly tac nghiep, cac he thong thong tin ho tro quyet dinh, cac he thong tin di£u hanh va he chuyen gia. Chuong trinh cung cung cap cho sinh vien nhung kien thuc co ban ve cong nghe thong tin va truyen thong - co so cong nghe cua cac he thong thong tin hien dai va d6 xuat mot mo hinh he thong thong tin phuc vu cong tac quan ly dieu hanh o mot So Van hoa - Thong tin tinh, nhu mot goi y tham khao cho nguoi hoc - nhung nha quan ly van hoa tuong lai. Giao trinh bao gom 6 ehuang: - Chuong 1. Thong tin va cac qua trinli thong tin. Trinh bay nhung kien thuc co ban ve thong tin. bao gom: khai niem thong tin va cac thuoc ti'nh lam nen gia tri cua thong tin: quan he giua thong tin. dir lieu va tri thuc; lich sir phat trien cua ky thuat truyen tin: cac nguon thong tin dien tu: vai tro cua thong tin voi su phat trien cua xa hoi: mo hinh t6ng quat cua cac qua trinh thong tin: day chuy£n thong tin tu lieu trong cac thu vien va cac trung tarn thong tin-mot trong nhung he thong thong tin dau tien cua loai nguoi. - Chuong 2. Quan ly va thong tin trong quan ly. Trinh bay nhirng kien thuc chung ve quan ly va nhung van de lien quan den thong tin trong quan ly, bao gom: khai niem chung ve t6 chuc va quan ly: cac chuc nang cua quan ly va cau true cua quyet dinh; cac dac trung cua thong tin a cac cap do quan ly khac nhau: cach trinh bay thong tin co hieu qua; qua trinh ra quyet dinh va nhu cau thong tin: van de quan ly du lieu doi voi nha quan ly. - Chuong 3. Tong quan ve cac he thong thong tin. Gioi thieu khai niem chung cac he thong thong tin dua tren may tfnh. bao gom: khai niem he thong va he thong thong tin: khai quat ve cac he thong thong tin tac nghiep. he thong thong tin quan ly va he chuyen gia: vai tro cua he thong thong tin trong hoat dong san xuat kinh doanh va quan ly hanh chinh: tac dong cua he thong thong tin trong xa hoi hien dai. 4 - Chirang 4. Cong nghe cua cac he thong thong tin. Trinh bay co so cong nghe cua cac he thong thong tin, bao gom: may tmh dien tu va cac vat mang tin dien tu; cac phan m£m he thong va phan mem chuyen dung; truyen thong dir lieu va mang may tfnh; cac he thong trong tin true tuyen; Internet va cac dich vu thong tin tren Internet; cach thuc quan ly dir lieu va tri thuc tren may tmh va trong cac he thong thong tin. - Chuong 5. Cac he thong thong tin quan ly. Noi dung chuong nay trinh bay nhirng kien thuc co ban cung cac ung dung cua cac he thong thong tin quan ly, bao gom: cac he thong thong tin tac nghiep (OIS), he thong thong bao cao (IRS), he thong thong tin h6 tro quyet dinh (DSS), he thong thong tin dieu hanh (EIS) va he chuyen gia (ES). - Chuong 6. Phat trien hei thong thong tin. Noi dung chuong nay trinh bay khai quat ve chu trinh phat trien mot he thong thong tin. vai tro cua nha quan ly trong viec xay dung he thong thong tin va thu de xuat mot mo hinh he thong thong tin phuc vu cho cong tac quan ly va dieu hanh 6 mot So Van hoa - Thong tin tmh. Cac he thong thong tin quan ly la mon hoc moi duoc dua vao chuong trinh dao tao can bo quan ly van hoa 6 trudng Dai hoc Van hoa Ha Noi. De phii hop voi doi tuong ngudi hoc, giao trinh tap trung cung cap nhirng kien thuc co ban va he thong ve noi dung, vai tro, tac dung va cach thuc xay dung cac he thong thong tin quan ly, di sau vao trinh bay nhung y tuong va phuong phap. ket hop voi nhieu vi du minh hoa tir thuc te, 5 khong sa vao nhirng van de mang tmh ky thuat. Mac dii da co nhiSu co gang, song cuon sach khong the tranh khoi nhirng thieu sot. Rat mong sir gop y cua d6ng nghiep va ban doc de cuon sach duoc tot hon. Trong qua trinh bien soan cuon sach chung toi nhan duoc su dong gop chan tinh cua cac dong nghiep, cac chuyen gia ve phan tich thiet ke he thong dang lam viec tai cac vien nghien cuu, cac trung tam thong tin. Cho phep toi duoc bay to loi cam on chan thanh. Ha Noi, thang 11 nam 2003 tAc g ia 6 CHLTONG 1 THONG TIN VA CAC QUA TRiNH THONG TIN 1. THONG TIN 1.1. Khai niem thong tin. Dur lieu, thong tin va tri thurc Thong tin (Information) la khai niem co ban cua khoa hoc cung la khai niem trung tarn cua xa hoi trong thoi dai chung ta. Moi quan he, moi hoat dong cua con ngudi deu dua tren mot hinh thuc giao luu thong tin nao do. Moi tri thuc d6u b&t ngu6n bang mot thong tin ve nhung di6u da didn ra, ve nhung cai nguoi ta da biet, da noi, da lam. Di6u do luon xac dinh ban chat va chat luong cua nhung moi quan he cua con ngudi. Vay thong tin la gi? Co rat nhieu cach hieu ve thong tin. Tham chi ngay cac tu dien cung khong the co mot dinh nghla thong nhat. Nguyen nhan cua sir khac nhau trong viec sir dung thuat ngu nay chfnh la do thong tin khong the so mo duoc. Nguoi ta bat gap thong tin chi trong qua trinh hoat dong, thong qua tac dong trim tuong cua no. Tir La tinh “informatio”, goc cua tir hien dai “information” co hai nghla. Mot, no chi mot hanh dong rat cu the la tao ra mot hinh dang (forme). Hai, tiiy theo tinh huong, no co nghla la sir truyen dat mot y tuong, mot khai niem hay mot bieu 7 tuong. Tuy nhien cung vai su phat trien cua xa hoi. khai niem thong tin cung phat trien theo. - Theo nghla thong thtfdng: Thong tin la tat ca cac su viec, su kien, y tuong, phan doan lam tang them su hieu biet cua con nguoi. Thong tin hinh thanh trong qua trinh giao tiep: mot nguoi co the nhan thong tin true tiep tir ngudi khac thong qua cac phuong tien thong tin dai chung, tir cac ngan hang dir lieu hoac tir tat ca cac hien tuong quan sat duoc trong moi trudng xung quanh. - T ien quan diem triet hoc: Thong tin la su phan anh cua tu nhien va xa hoi (the gidi vat chat) bang ngon tir, ky hieu, hinh anh v.v... hay noi rong hon bang tat ca cac phuong tien tac dong len giac quan cua con ngudi. - Sir vat luon van dong, d trang thai bat dinh va chua dung tinh ngau nhien. Tang luong tin tuc ve mot hien tuong nao do cung la giam do chua biet hoac do bat dinh ciia no. Vi vay tren quan diem cua ly thuyet thong tin thi thong tin la sir loai trir tinh bat dinh cua hien tuong ngSu nhien. Tinh trat tu doi lap vdi cai bat dinh va ngau nhien la thuoc ti'nh co ban cua thong tin ma khoa hoc phat hien. Theo do thong tin phan anh cai xac dinh, trat tu trong cac moi quan he cua cac su vat va hien tuong. Vdi y nghla do thong tin la luong do trat tu nhan tao chong lai su hdn don cua tu nhien. Chinh di^u do giai thfch y nghla to ldn cua thong tin trong moi linh vuc hoat dong ciia con ngudi. Trong ddi song con ngudi, thong tin la mot nhu cau rat co ban. Nhu cau do khong ngung tang len cung vdi su gia 8 tang cac moi quan he trong xa hoi. Mdi nguoi sir dung thong tin lai tao ra thong tin moi. Cac thong tin do lai duoc truydn cho nguoi khac trong qua trinh thao luan, truyen dat menh lenh, trong thu' tir va tai lieu hoac qua cac phuong tien truyen thong khac. Thong tin duoc to chuc tuan theo mot so quan he logic nhat dinh, tro thanh mot bo phan ciia tri thuc, doi hoi phai duoc khai thac va nghien cuu mot cach he thong. Trong hoat dong ciia con nguoi thong tin duoc the hien qua nhieu hinh thuc da dang va phong phu nhu: con so, chu viet, am thanh, hinh anh v.v... Thuat ngu thong tin dung d day khong loai trir cac thong tin duoc truyen bang ngon ngu tu nhien. Thong tin cung co the duoc ghi va truydn thong qua nghe thuat, bang net mat va dong tac, cir chi. Hon nua con ngudi con duoc cung cap thong tin dudi dang ma di truyen. Nhung hien tuong nay ciia thong tin tham vao the gidi vat chat va tinh than cua con ngudi, cung vdi su da dang phong phu ciia no da khien kho co the dua ra mot dinh nghla thong nhat ve thong tin. D u lieu, thong tin va tri thuc Thong tin co nhieu muc do chat luong khac nhau. Cac so lieu, su kien. hinh anh ban dau thu thap duoc qua di£u tra, khao sat la cac thong tin nguyen lieu, con goi la chi lieu (data). Thuat ngu du lieu - data co xuat su tu chu Latin datum , co nghla la "cai da cho" hay su kien. no co the co dang mot con so, mot su tiinh bay hoac hinh anh. Du lieu co the co hai dang: dang co cau true nhu cac bieu ghi. cac co so du lieu: dang phi cau true nhu cac tep van ban, dang 9 nay thuong chiem den 80% luong dir lieu cua mot t6 chuc. Dac trung co ban cua du lieu la chung co the t6 chuc, luu tru va luu truyen trong cac he thong va mang luoi thong tin. Khi dir lieu qua xir ly, phan tfch, tong hop va duoc cho la co y nghla cho mot doi tuong, mot cong viec nao do thi chung se tro thanh thong tin (inform ation). Thong tin la su phan anh ve mot vat, mot hien tuong, mot su kien hay qua trinh nao do ciia tu nhien va xa hoi thong qua khao sat true tiep hoac ly giai gian tiep. Cac thong tin nay neu tiep tuc dupe xir ly se tao ra cac san pham thong tin co gia trj cao hon, con goi la thong tin co gia tri gia tang (value added information). Trong truong hop nay thong tin da thuc su tro thanh hang hoa. Du lieu mo ta su viec chu khong danh gia su viec con thong tin luon mang mot y nghla xae dinh va noi chung g6m nhieu gia tri du lieu. Noi cach khac thong tin la du lieu co y nghla. T, O muc do cao hon nua la cac thong tin quyet dinh trong quan ly va lanh dao - ket qua xir ly ciia nhung nha quan ly co nang lire va kinh nghiem, cac thong tin chua dung trong cac quy luat, nguyen ly ciia khoa hoc - ket qua cua nhung cong trinh nghien cuu, thir nghiem cua cac nha khoa hoc va chuyen mon, v.v... Khi do thong tin tro thanh tri thuc (knowledge). Nguoi ta co the thu nhan dupe tri thuc bang tu duy tren cac thong tin da qua xir ly. Chi co nhung thong tin dupe tri oc ciia con nguoi tiep nhan va dupe xir ly tfch cuc qua qua trinh suy nghl, hoc hoi de nhan thuc moi tro thanh tri thuc. Tri thuc bao g6m tat ca nhung hieu biet ciia con nguoi va dupe so huu boi con nguoi. Thong tin la "cai ciia 10 ngirai", con tri thuc la "cai cua minh". Co the noi tri thuc la tap hap cac thong tin huu fch da duoc tri tue cua con nguoi xac nhan va dua vao su dung trong thuc ti£n. Theo to chuc hop tac va phat trien kinh te OECD (Organization for Economic Cooperation and Developement) thi: tri thuc la toan bp ket qua v6 tri lire cua con nguoi sang tao ra tir trudc den nay, trong do tri thuc ve khoa hoc, v& ky thuat, v6 quan ly la cac bo phan quan trong nhat. Sir phan chia khai niem du lieu, thong tin va tri thuc chi la tuong doi. Du lieu ciia nguoi nay co the la thong tin doi voi nguoi khac; tuong tu, thong tin doi vai ngudi nay co the la tri thuc doi voi ngudi khac. Ngay tir thdi cd dai con ngudi da biet "Tri thuc la sue manh". Ngay nay tri thuc dang true tiep tao ra quyen luc, tien bac va sue canh tranh. Tri thuc la thong tin mang dau an cua mot con ngudi, cho nen kha nang n4m bat va ap dung tri thuc chuyen mon ciia cac thanh vien trong to chuc dong vai tro co ban de duy tri va tao ra lpi the canh tranh ciia to chuc do. Dieu do ly giai tai sao nguon lire con ngudi bao gid cung la quan trong nhat trong bat ky he thong to chuc nao. Cac dac trung cua mot thong tin tot Khong phai moi thong tin deu co gia tri nhu nhau. Thong tin nay cd the tot hon thong tin kia. Trong cong viec hang ngay ban co the tiep nhan hang ngan thong tin khac nhau. Vay thong tin nhu the nao la thong tin tot, dac trung ciia chung la gi? Thu nhat, thong tin phai thich hop (pertinence). Dieu do co nghTa la thong tin phai dap ung duoc vdi yeu cau cua nguoi su dung, thong tin phai giup nguoi dung tin giai quyet duoc van de ma ho dang dat ra trong cong viec cua ho. Thu hai. thong tin phai kip thoi (tim eliness). Dieu do co nghla la thong tin phai duoc cung cap dung luc ma ngudi dung tin can. Vi du, nhung thong tin v& gia ca mot mat hang nao do se mat het y nghla neu no khong den kip thoi, vi gia ca luon thay ddi tirng ngay, tham chi tirng gid. Thu ba, thong tin phai chinh xac (accuracy). Tinh chfnh xac la yeu cau bat buoc ddi vdi moi thong tin. Neu cac so lieu trong mot ban thong ke ma khong chfnh xac, thi moi ket luan rut ra tir cac so lieu do cd the dan den sai lam hoac cd hai. Ngoai ra thong tin tot con la thong tin co tac dung giam bot tinh bat dinh (reduced u n cu rtain ty). Va nhu vay thong tin dem lai sir on dinh cho sir vat. Thong tin tot con la thong tin chua dung yeu to bat n go (elem ent o f surprise). Dieu do the hien tinh mdi cua thong tin. Cac yeu to co ban trong xu ly thong tin Con ngudi nhan thong tin thong qua cac giac quan: am thanh qua thfnh giac; hinh anh va van ban qua thi giac; trang thai, nhiet do, cam xuc qua xiic giac; mui vi qua khiru giac. De giai thich va hieu duoc cac tin hieu nhan duoc tir cac giac quan, con ngudi phai phat trien va hoc cac he thong ngon ngu phirc hop, no bao gdm mot "bo chu cai" cac 12 tin hieu va cac tac nhan kfch thich cung vai cac quy tac su dung chung. Dieu do cho phep nguoi ta nhan ra cac doi tuong ma ho nhin thay, hieu duoc cac thong bao ma ho doc hoac nghe, cam nhan duoc cac tin hieu nhan duoc qua xuc giac va khuu giac. Cac vat mang thong tin chuyen tai tin hieu toi nguoi nhan co the la song dien tir, song anh sang, song am va cac tac nhan kfch thfch hoa va dien hoa. Cho den trudc khi may tfnh dien tu ra doi. cac tin hieu truyen di thong qua cac vat mang tin tren la nhung tin hieu duoc luu tr£r va xir ly dudi dang tuong d6ng, dua tren cong nghe in. chup anh va dien thoai. Vdi cong nghe thong tin hien dai. thong tin duoc bieu dien dudi dang cac tin hieu so nhi phan. dua tren ky thuat so. Do cd the coi la budc chuyen bien mang y nghla lich su vao cuoi the ky XX trong cach thuc ma con ngudi sang tao, tiep can va sir dung thong tin. Vdi ky thuat so, may tfnh dien tir trd thanh cong cu chu yeu xir ly thong tin. May tfnh dien tir thu nhan dir lieu, xir ly rat nhanh cac du lieu do de bien chung thanh thong tin huu fch. phuc vu cho nhu cau thong tin da dang ciia con ngudi. 1.2. Giao liru thong tin va Ijch sir phat trien cua ky thuat truyen tin Thong tin tiem tang khap noi trong xa hoi. Do la cac nguon thong tin ve lao dong, dat dai, tai nguyen, moi trudng; thong tin ve cac to chuc va cac hoat dong kinh te, xa hoi; thong tin ve khoa hoc va cong nghe; thong tin ve san xuat, kinh doanh v.v... Nhung thong tin chi cd gia tri va y nghTa khi no duoc truyen di. phd bien va duoc sir dung. Co the noi ban chat cua thong tin nam trong su giao luu cua no. De phan biet noi dung thong tin can truyen di va cach thuc chuyen giao thong tin nguoi ta tach noi dung thong tin ra khoi hinh thuc bieu di6n no. Cac hinh thuc bieu diln thong tin (cac ky hieu, dau hieu, hinh anh...) la huu han nhung noi dung cua thong tin (khai niem. y tuong, su kien, ten v.v...) thi vo han. Trong trudng hop thong tin co mot hinh thuc bieu di£n, qua trinh chuyen giao thong tin chfnh la qua trinh truyen cac ky hieu bieu didn no. Nhung y tuong moi se duoc truyen di bang mot to hop mdi cua mot so hiru han cac ky hieu (chu cai, chu so...). Trong doi song hang ngay thong tin duoc bieu di6n bang ngon ngu. Khi do thong tin duoc dien ta bang cu phap va ngu nghia cua ngon ngu ma nguoi ta su dung. Ban chat cua thong tin nam trong sir giao luu cua no. Do do lich su phat trien cua thong tin gan lien voi lich su phat trien cua ky thuat t/ruyen tin. Tieng noi Tieng noi hay ngon ngu noi dong vai tro n6n tang trong truyen thong xa hoi. Do la phuong tien truyen tin tho so nhat. no khong luu giu duoc thong tin theo thoi gian va kha nang truyen rat han che trong khong gian. Tuy nhien loai nguoi da ton tai rat lau nho phuong thuc truyen tin nay. Cac nha ngon ngu hoc dem thay co khoang ba ngan ngon ngu noi ngay nay (bon ngan ngon ngu khac da bien mat) va khoang mot vai tram trong so do dugfc thuc su ghi lai nho 14 chu viet. Sir phat trien cua ngon ngu la tieu chi danh gia sir phat trien va trinh do van minh cua mot bo toe. Sir phong phu cua tieng Viet noi len truyen thong van hien lau ddi ciia nguoi Viet. Theo co Thu tuosg Pham Van Dong tieng Viet ciia cua chung ta rat giau, rat dep. " Chfnh cai giau dep do lam nen cai chat, gia tri, ban sdc, tinh hoa ciia tieng Viet, ket qua cua ca mot qua trinh va biet bao cong sire d6i mai". De minh hoa cho nhan dinh do, Ong da lay vf du mot cau ca dao: H ai co tat nuac ben dang Sao co miic anh trang vang do di? va mot cau tho trong truyen Kieu: Long I anh day nuac in trai Thanh xay khoi biec non phai bong vang. r6i binh luan: " Do la nhung cau rat hay, la hai hon ngoc. Mot la hon ngoc hay con moc mac ciia dan gian, va mot hon ngoc da qua tay cua ngudi tho thien tai". C hu viet Chu viet hay van tu, la ky thuat ghi lai ngon ngu noi, do la mot thu ky thuat cach mang. Nhd do ngudi ta cd the ghi lai duoc cac thong tin. Lich sir phat minh ra van tu di£n ra hai dot noi tiep nhau, ung vdi hai phuong thuc van tir khac nhau ve hinh thai: - Van tu tuong hinh: ra ddi tai Mesopotamie (mot mien dat d Tay A giua hai con song Tigre va Euphrate) khoang 15 4000 nam trudc Cong nguyen, thoat dau mang tfnh thuan tuy tuong hinh. roi dan dan mang tfnh truu tuong hon. Trong ngon ngu tuong hinh. moi bieu tuong co the dien ta tron ven mot khai niem. Cac bieu tuong nay trai qua nhieu thay doi ve hinh dang khien su tuong> d6ng giura chung va cac doi tuong ma no thay the dan dan mat di, nhung y nghla cua chung thi ngay cang r5 rang hon. Cac bieu tuong nay duoc goi la mau tir. Ngon ngu cang phat trien thi mau tu ngay cang nhieu. He thong chu tuong hinh cua Trung Quoc ngay nay co den tren 50 000 mau tu. Chu tuong hinh ngay nay duoc sir dung 6 cac nuac Bac Phi. Trung Can Dong, Dong A, Nam A, Dong Nam A... Viet Nam la truong hop hiem hoi 6 Dong Nam A dung he thong chur cai La tinh de ghi lai tieng Viet. Do la do nha truyen giao nguoi B6 Dao Nha A. de Rhodes sang tao ra vao giua the ky XVII, nham phuc vu cho viec truyen giao. Cuon tir dien Viet - Bo - La cua A. de Rhodes xuat ban lan dau tien vao nam 1651. - Van tir chu cai: Trong qua trinh phat trien cua ngon ngu viet, den mot luc phuong phap bieu didn da thay d6i tir tuong hinh sang tuong thanh. ma 6 do am thanh noi duoc bieu dien bang mot bo chu cai bao gom cac ky hieu do hoa. Cac t6 hop khac nhau cua mot bo phan cac ky hieu nav co the thay the cho nhung khai niem phuc hop hon nhu cac tu. cac cau. Van tu chu cai bat nguon tir nguoi Pheniciens (cu tru o viing dat Syri ngay nay) vao khoang tir 2000 den 1000 nam truoc Cong nguyen, roi dan hinh thanh o Hy Lap vao 16 nhirng nam 800 den 600 trudc Cong nguyen. He thong mSu tu Hy Lap la su khdi dau ciia mSu tu La tinh ma sau nay duoc dung lam co so chung cho tat ca cac he thong chu viet d phuong Tay. Viec phat minh ra chir viet mang mot tam voc xa hoi rat to Ion. Ngay sau khi ra ddi chir viet da duoc sir dung lam ky thuat truyen thong va do do da bien doi sau sSc cac phuong thuc giao luu tu tuong va truyen ba thong tin. Tir khi cd chu viet mdi cd nghe chep sir, con ngudi thoat khdi thoi ky truyen thuyet; nghe buu chfnh ra ddi, giup con ngudi trao ddi thong tin tir xa; nghe bao chf hinh thanh nhu mot cong cu thong tin dai chung dau tien; giao due tro thanh hoat dong xa hoi co td chuc, thuc hien chuc nang chuyen giao thong tin giira cac the he. Ky thuat an loat • Nghe in Ky thuat an loat ra ddi vao the ky XV vdi phat minh ra may in bang chir rdi ciia Gutenberg da bien tai lieu viet thanh sach in vdi kha nang nhan ban rat ldn. Ke tir khi cuon sach dau tien duoc in typo la bo thanh thi Mayence vao nam 1457 den nam 1500 da cd gan 20 trieu ban ciia 35 000 dau sach duoc in ra. Sach in da tro thanh cong cu chu yeu truyen ba cac tu tuong mdi me, trd thanh mot trong nhung nguyen nhan tao ra nhung chuy6n bien thdi Phuc hung (The Renaissance). Y nghia to ldn cua viec phat minh ra may in la d chd no da lam thay ddi chuc nang cua sach. Tir chd chi la mot cong cu luu trir van ban. sach da trd thanh mot cong cu vo song 17 cua truydn thong, roi cung tu do sach trd thanh mot doi tuong cua thuong mai. Co the noi nghe in la mot thanh tuu ky thuat to Ion, tao dieu kien cho con nguoi giao luu thong tin rong khap, thuc day manh me su phat trien cua xa hoi v6 khoa hoc ky thuat cung nhu van hoa noi chung. Tu nay thong tin co the ghi lai va ph6 bien voi khoi luong ldn. Hoat dong nghien cuu khoa hoc trd thanh mot hoat dong xa hoi cd to churc va giao luu khoa hoc phat tri6n tren pham vi toan the gidi. Cung vdi viec phat minh ra may in, viec phat minh ra may chu vao the ky XVIII da gop phan co gidi hoa viec ghi cac tai lieu van ban. Tiep theo viec phat minh ra phim va ky thuat chup anh vao the ky XIX da cho phep con ngudi lan dau tien cd the ghi lai cac thong tin bang hinh anh mot cach chfnh xac. Cong nghe thong tin hien dai Nhung thanh tuu to ldn cua khoa hoc va cong nghe trong nua cuoi the ky XX da dan den sir phat trien bung nd cong nghe dac biet tren ba llnh vuc lien he chat che vdi qua trinh xir ly thong tin la: tin hoc, vi6n thong va vi xir ly, hat nhan ciia cong nghe thong tin hien dai. Viec sir dung cac cong cu do con ngudi che tao ra de’ thu thap, san sinh, ghi chep, sap xep lai, truyen va khai thac thong tin da cd tir rat lau. Nhung chi tir khi may tfnh dien tir ra ddi (1946) va dac biet vdi cuoc cach mang vi xir ly vao giua nhung nam 70 tao co so cho su ra ddi hang trieu, rdi hang chuc. hang tram trieu may vi tfnh vdi nang lire ngay cang cao, gia ngay 18 cang re, tham nhap khap moi noi tren the giai. mdi thuc sir mo ra mot chan troi moi cho m6i ca nhan va xa hoi trong viec nam bat duoc nhirng thong tin v6 nhirng sir kien va y tuong moi va moi tao kha nang hien thuc cho viec hien dai hoa cac hoat dong thong tin. Cuoi nhung nam 80 sang dau nhung nam 90. su phat trien . bung no cac mang vi6n thong truyen du lieu quoc gia va quoc te tren co so ky thuat cap soi quang. ve tinh va vi ba so da tao kha nang noi mang khong nhung giua cac trung tarn tfnh toan, ma con noi duoc den may vi tfnh ciia tirng ca nhan. Xuat hien cac mang thong tin may tinh, roi den cac sieu “xa lo thong tin” lien ket hang tram trieu nguoi trong tirng quoc gia cung nhu trong pham vi khu vuc va toan cau, ma tieu bieu la lien mang thong tin toan cau Internet. Cung voi viec phat trien manh me cac ky thuat vi xir ly, viec sir dung ngay cang nhieu cac vat mang tin dien tir: bang tir, dla tir, dia quang da loai bo duoc nhirng kho khan ve sir qua tai ciia cac kho chua. dong thoi tao dieu kien thuan lai cho viec chuyen giao va phan phoi thong tin voi nhirng kenh rat da dang. Trong do, dac biet phai ke den dla m6m ra dai nhung nam 70 ciia the ky XX duoc sir dung rat thuan loi cho cac may tfnh ca nhan va dia quang ra dai dau nhung nam 80 cho kha nang luu trir thong tin da phuong tien vai dung luong Ion. N ha cong nghe thong tin va truyen thong, toe do xir ly thong tin ngay cang nhanh, kha nang truy cap toi cac nguon thong tin ngav cang mo rong va nhu cau hop tac trong moi truong thong tin ngay cang phat trien. Cac ung dung 19 Internet ngay cang trd nen pho cap dang md rong kha nang tiep thu tri thuc va hudng thu van hoa, nang cao chat luong dich vu xa hoi, lam thay doi manh me phuong thuc giao tiep va le loi lam viec cua con ngudi. 1.3. Nguon thong tin dien ta Cac thong tin chi cd the luu giu va truyen qua khong gian va thoi gian neu no duoc ghi lai tren cac gia vat chat, vdi nhi6u dang va hinh thuc khac nhau. Chung duoc goi chung la tai lieu. Tai lieu co the dinh nghla la mot vat the cung cap nhung chi dSn va thong tin. Do la cai gia vat chat mang tri thirc cua nhan loai. Cac tai lieu truydn thong thudng gap la sach, bao, tap chi, bang bieu, so do, ban do, tranh anh, dia hat,... Viec ung dung cong nghe thong tin trong hoat dong thong tin tu lieu, dac biet viec sir dung ky thuat so de bieu di6n thong tin da dan den viec ra ddi mot loai hinh tai lieu mdi, do la cac tai lieu dien tu. Va tir do cung xuat hien khai niem thong tin dien tu. Cd the coi thong tin dien tu la tat ca cac thong tin duoc truy cap tren may tinh. Thong tin dien tu duoc trinh bay va luu trir tren cac vat mang tin dien tu. Do la cac bang tir, dia tir, dia quang. Chung tao thanh nguon tai lieu dien tir. Cac co sd du lieu do don vi thong tin xay dung la thong tin dien tir cd the truy cap true tiep tren may tinh. Nhung nguon thong tin dien tu ddi dao nhat la nguon thong tin true tuyen duoc truy cap tren may tinh thong qua mang Internet hoac cac mang may tinh. 20 Thong tin dien tir bao gom: - Cac co so du- lieu chuyen nganh, da nganh luu tru tren cac dia tir, bang tir, dia quang CD-ROM. - Cac co so dir lieu true tuyen do cac co quan thong tin xay dung, muon sir dung phai dang ky voi mot server de duoc quyen truy cap. - Ban tin dien tir. do mot co quan phat hanh, thuong dat trong trang chii cua don vj minh tren mang Intranet, Internet. - Bao va tap chi dien tir, duoc an hanh tren mang Internet. - Cac Website tren Internet, chua thong tin v i co quan hanh chfnh sir nghiep, cac doanh nghiep, cac cong ty, cac trudng dai hoc, ... Viec truy cap thudng la midn phf. - Cac so so tri thuc, chua he thong cac luat dung de xac dinh va thay ddi cac mdi lien he giCra cac su kien dau vao. Tat ca cac dang thong in tren tao thanh nguon thong tin dien tir (Electronic Information Resouces) hay con goi la nguon thong tin so (Digital Information Resouces). Thong tin dien tir cd nhirng dac trung ndi bat sau day: - Cd mat do thong tin cao. Chi can tir 4 den 5 dia CD ROM cd the luu tru toan bo noi dung trong mot nam ciia bo C hem ical Abstract gom 100 tap. mdi tap 2000 trang. - Thong tin luon mdi nho cd kha nang cap nhat nhanh. thudng xuyen va kip thoi. 21 - Thong tin co the luu tru 6 nhidu dang khac nhau: van ban, do thj, am thanh, hinh anh tinh va dong. - Co kha nang truy cap theo nhidu dau hieu khac nhau: tac gia, nhan de, tu khoa, nam xuat ban, ... - Co kha nang truy cap tu xa, khong gidi han v£ khong gian, thoi gian. - Cung mot thoi diem co the nhi6u nguoi truy cap. - Tao kha nang cho nguoi dung tin co the tiep can voi tac gia thong qua kenh thong tin phan hoi. Ben canh nhung uu diem tren day, thong tin dien tir cung co nhung nhuoc diem va han che: - Tfnh on dinh khong cao, do b6n vung khong d6ng nhat: co thong tin ton tai lau dai nhu cac thong tin ghi tren CD ROM, nhung cung co nhung trong tin co vong doi rat ngdn nhu cac ban tin, bai bao tren mang Internet. - Dd bi vi pham ban quyen, do bi sao chep, sua ddi, tham chi bi huy hoai do nhung vi pham co tinh. Voi sir phat trien cua cong nghe thong tin va truyen thong, cac nguon tai lieu dien tu phat trien rat nhanh theo cap so nhan. Chi rieng tap chi dien tu nam 1991 moi co 110 ten tap chi dien tu, thi nam 1995 con so do la la 700, nam 1998 la khoang 5000, nam 2002 so ten tap chi dien tu da len toi tren 6000. Ngudi ta du bao trong 5 nam toi co the tat ca cac tap chi khoa hoc se duoc xuat ban dudi dang dien tir. Ngay nay thong tin dien tu giu vai trd quan trong trong giao luu thong tin va trong moi llnh vuc hoat dong ciia con ngudi. 22 2. VAI TRO CUA THONG TIN Ngay tu xira thong tin da dong vai tro to chtic va phat trien xa hoi. Bat cur cong dong nao cung chi co the ton tai bang cach truydn tin, du do mdi chi la tieng noi, tin hieu, hinh anh hay cir chi. Vai tro do cua thong tin trudc het la do cac gia tri ma thong tin dem lai. Trong mot nghien cuu moi day, nguoi ta thay co bon yeu to tac dong den chat luong thong tin va dem lai gia tri cho no. Do la: tinh chinh xac, pham vi bao quat cua noi dung, tinh cap nhat va tan so sir dung. Trong do quan trong nhat la noi dung, thu den la tinh chinh xac. Tren binh dien tong quat, ta thay rang thong tin co gia tri la nhung thong tin co tinh chat rieng biet va thong tin co tinh chat du bao. Tinh chat rieng biet lam cho thong tin phu hop voi yeu cau ciia nguoi sir dung. Con tinh chat du bao cho phep ngudi ta co the lira chon mot quyet dinh trong nhieu kha nang cho phep. Co the noi them rang gia tri nhan thirc ciia thong tin du bao lien quan mat thiet den tinh dung dan ciia viec lua chon quyet dinh. Tren mot y nghla rong hon, gia tri ciia thong tin nam trong quyen luc t6 chuc cua no. Thong tin phan anh cai xac dinh, trat tu trong cac mdi quan he ciia to chuc. Thong tin cd gia tri cao cho phep ngudi ta cd the lam mdi trudng tot len va cd the ra nhung quyet dinh ddi pho duoc vdi su thay doi ciia hoan canh. Tinh chat quyen luc nay ciia thong tin con nam trong cach no co the tuong trung cho nhung kien true vat chat va tinh than va duoc phan anh trong cac dinh 23 nghla cua tu dien ve dong tu "thong tin": "Thong tin la sap xep, hinh thanh, tao thanh (tri tue va tfnh cach...) bang cach truyen dat kien thuc" (Oxford English Dictionary). Nguoi ta sdm nhan thuc duoc rang mot khi da nam duoc va truyen duoc thong tin thi tuc la da co them mot thu quyen luc, giong nhu mot sure manh vat chat. Co the noi moi thanh tao cua lich sir deu phu thuoc vao thuc trang ciia cac dong tin, cung nhu phu thuoc vao san xuat va trao ddi hang hoa. Ngoai ra qua trinh t6n tai va phat trien ciia xa hoi gan chat voi sir chuyen giao thong tin giua cac the he, trong do giao due va dao tao giu vai tro trong yeu. Trong thoi dai ngay nay, thoi dai ma khoa hoc va cong nghe ngu tri trong doi song tat ca moi nguoi thi thong tin - yeu to tiep sinh khi cho no - giu vai tro cuc ky trong yeu. Vai tro do the hien tren cac mat sau day: 2.1. Thong tin la nguon lire phat trien va la nguon tai nguyen dac biet cua moi quoc gia Hien nay nguoi ta thua nhan rang vat chat, nang luong. thong tin va ban sac van hoa dan toe la cac nhan to quyet dinh sir ton tai va phat trien cua m6i quoc gia. Dac biet trong dieu kien cach mang khoa hoc va cong nghe dang didn ra voi quy mo Ion nhu hien nay, khoa hoc va cong nghe dang trd thanh luc luong san xuat true tiep cua xa hoi thi thong tin khoa hoc va cong nghe that su tro thanh ngudn lire quan trong tao nen nhung uu the kinh te va chinh tri cua m6i nude. Va neu nhu tiem luc khoa hoc va ky thuat la didu kien de nang cao nang suat, hieu qua cua nen san xuat xa 24 hoi thi thong tin khoa hoc va cong nghe duoc coi la yeu to cuc ky quan trong cua ti6m luc khoa hoc ky thuat. Neu nhu truoc day moi nen kinh te ddu dua chu yeu vao cac ngu6n tai nguyen thien nhien, lay viec khai thac va che bien cac tai nguyen thien nhien la ngu6n chu yeu tao ra cac cua cai va su giau co cho xa hoi, thi tu nhung nam cuoi cua the ky XX, thong tin da duoc xem la mot ngu6n tai nguyen kinh te, giong nhu cac tai nguyen khac nhu vat chat, lao dong, tidn von... boi vi viec so huu, su dung va khai thac thong tin co the dem lai hieu qua kinh te cho nhieu qua trinh vat ly va nhan thuc. Ngay nay cac hoat dong lien quan den xii ly thong tin trong cong nghiep che tao cung nhu trong viec giai quyet cac van de xa hoi va con nguoi tang len dang ke. Khac v6i cac nguon tai nguyen khac, tai nguyen thong tin co the mo rong phat trien khong ngung va hau nhu chi bi han che boi thoi gian va kha nang nhan thuc cua con nguoi. Kha nang mo rong nay the hien 6 cac thuoc tfnh sau day: 1. Thong tin lan truyen mot cach tu nhien; 2. Khi sir dung thong tin khong bao gio bi can di ma trai lai cang tro nen phong phu do duoc tai tao va bo sung them cac nguon thong tin moi; 3. Thong tin co the chia se, nhung khong mat di trong giao dich. Voi kha nang thay the cac nguon tai nguyen khac, kha nang truyen voi toe do rat cao va kha nang dem lai uu the 25 cho nguoi nam giu no, thong tin da thuc su trd thanh co so cho nhieu hoat dong xa hoi nhu nghien cuu, giao due. xuat ban, tiep thj va ca hoat dong chinh tri nira. Moi quan tam cua xa hoi ddi vdi viec sir dung cd hieu qua cac ngudn tai nguyen thong tin da md rong tir cac linh vuc truydn thong nhu thu vien, luu tru sang cac to chuc, cac co quan, cac nganh. Bay gid d dau ngudi ta cung quan tam den viec quan ly va khai tac cac ngudn tai nguyen thong tin. Mot khfa canh nhan thuc thu: hai ve vai trd ciia thong tin trong nhung nam g chuc. Chung co the phan chia theo cac llnh vuc co ban sau: Thong tin kinh te. xa hoi. Thong tin v6 dan cu, lao dong. Thong tin v6 tai nguyen, dat dai. Thong tin v& khoa hoc, cong nghe, moi truong. Thong tin v& ke hoach, dau tu. Thong tin v& tai chfnh, ngan sach. Thong tin ve cong chuc, vien chuc nha nuac. Thong tin v6 phap luat. Thong tin ve van hoa va nghe thuat. Thong tin ve cac doanh nghiep hoat dong tren dia ban. Thong tin ve cac du an trong diem tren dia ban. v.v... Cac nha quan ly co the tim cac thong tin nay o dau? Cau tra lai la cac thong tin nay co the tim trong cac nguon tai lieu. Tai lieu (document) la cai gia vat chat mang tri thuc cua nhan loai. Tap hop tat ca cac tai lieu cua mot don vi thong tin tao thanh nguon luc thong tin cua don vi do. Ngu6n luc thong tin (Information resources) la thanh phan trung tam cua moi he thong thong tin va la nguyen lieu cho moi qua trinh hoat dong trong he thong. Nguon luc thong tin la co so de tao ra cac san pham va dich vu thong tin. Do la yeu to bao dam cho chat luong dap ung yeu cau tin. Co nhieu loai hinh tai lieu. Can cur vao hinh thurc the hien thong tin thi co bon loai tai lieu chfnh: 70 - Tai lieu tren giay: sach, bao, tap chi, cac ky yeu hoi nghi. luan an. tai lieu phat minh sang che, cac thong bao, cac an pham thu muc, cac tieu chuan, cac catalog ky thuat va thuong mai, cac van ban v6 phap luat va hanh chinh, cac tap ban do, do bieu. cac s6 tay, ghi chep. ban thao, ... - Tai lieu nghe nhin: phim anh, bang nhac, bang hinh, dla hinh, dla am thanh,... - Tai lieu co ban chat vat chat: cac tuong dai, cac m5u vat, cac san pham mau, cac ma-ket (maquettes), cac giao cu true quan... - Tai lieu dien tu: cac CSDL. cac an pham va thong tin tren CD-ROM, cac bao dien tu, tap chi dien tu, cac Website tren mang Internet, cac phan mSm may tinh, ... Neu can ctf vao muc do pho bien nguoi ta phan biet tai lieu cong bo va tai lieu khong cong bo. Tai lieu cong bo la nhung tai lieu co ban rong rai tren thi truong, ai cung co the mua duoc 6 cac hieu sach hoac a cac co quan xuat ban. Tai lieu khong cong bo la nhung tai lieu khong co ban tren thi trudng va muc do ph6 bien ciia no rat hep. Chung tao thanh mot loai tai lieu ngam. Mot so la nhung ban chep tay hay danh may, mot so la nhung ban chup lai hay in lai voi so luong rat han che. Do la nhung ghi chep nhat ky khoa hoc, nhung bao cao ket qua nghien cuu, nhung luan van khoa hoc, nhung giao trinh giang day, tai lieu hoi nghi. Bat ngu6n tu nhung co so rat khac nhau nhu cac vien nghien cuu, cac trudng dai hoc, cac hoat dong hoc tap 71 nghien cuu, v.v... nhirng tai lieu nay thudng chua nhirng thong tin mdi nhat trong llnh virc ma no xem xet. nhung thong tin co gia tri cao. tuy chua duoc tham dinh va ket luan mot cach chfnh xac. Mac du khdng biet sd luong cua nhirng tai lieu nay la bao nhieu. nhung ngudi ta biet chic ring sd luong cua chung hien nay gia tang rat dang ke. Viec tiep can cac tai lieu nay la rat can thiet, nhung doi hdi nhieu cong sue va thdi gian. Cac thong tin khi dua vao he thong thong tin dua tren may tfnh phai duoc trai qua qua trinh tien xir ly, phan loai ciia cac chuyen gia co kinh nghiem trong cong viec de nang cao gia tri sir dung ciia thong tin (cho phep bien ddi thong tin tir luong thanh chat). O day chat luong thong tin se phu thuoc vao kien thuc chuyen gia cua cac chuyen vien xu ly. Cac thong tin thuoc llnh vuc khac nhau se co cau true du lieu khac nhau va do do se duoc to chuc, quan ly va khai thac tren cac co sd dir lieu khac nhau, thong qua mot co che thong nhat. giup cho ngudi sir dung tim tdi thong tin mot cach nhanh chong va thuan tien. He thong cac co sd du lieu chfnh la cai ldi thong tin cua toan bo he thong t6 chuc va la thanh phan co ban cua moi he thong thong tin quan ly. Cac thong tin nay ngay cang trd nen phong phu do duoc bd sung thudng xuyen trong qua trinh sir dung. De dat dugc hieu qua trong sir dung va trao doi thong tin, cac thong tin trong he thong cac co sd du lieu can phai dugc chuin hoa trong cau true du lieu, trong cac bieu mau nhap tin va bieu m iu trinh bay du lieu. 72 3.3. Van de quan Iv dir lieu doi voi nha quan ly Ngay nay khong ai con nghi ngd gi ve vai tro cua thong tin trong khoa hoc ky thuat va ddi song cung nhu trong moi van dong ciia xa hoi dudi moi quy mo. tir cac don vi xi nghiep cho den quoc gia va ca quoc te. Viec nam bit thong tin nhanh chong, day du. chinh xac va kip thdi ngay cang dong vai tro cot tu trong quan lv va dieu hanh. Noi cach khac ngay nay noi quan ly thuc chat la quan ly thong tin. Song moi thong tin can quan ly tren may tinh theo bat cu quy trinh cu the nao cung deu duoc the hien bing cac dur lieu ghi tren mot vat mang tin nao do. Bdi vay khi noi den quan ly thong tin turc la quan ly du lieu. Du lieu la ngu6n luc song con ciia tci chuc. no can duoc quan ly nhu bat ky tai san quan trong nao ciia to chuc. Mot tc> chuc se khong the ton tai hoac thanh cong neu khdng co ngudn du lieu co chat luong ve cac hoat dong ben trong va mdi trudng ben ngoai ciia to chuc. Vi vay quan ly ngudn du lieu (Data resouce management) la yeu cau luon duoc dat ra ddi vdi moi t6 chuc va cac nha quan ly. Viec quan tri du lieu tren may tinh duoc thuc hien nhd hai dang chuong trinh sau: - Cac he thong quan ly tep. - Cac he thong quan tri co so du lieu. Vdi he thong quan ly tep, cac du lieu cin thiet cho ngudi su dung duoc luu tru trong cac tep rieng biet. va duoc to chuc theo nhung cach khac nhau. Moi tep lai duoc t6 chuc va sir dung cac chuong trinh ung dung khac nhau va khong chuong 73 trinh nao co the tao ra cac thong tin dudi dang ma ngirdi sir dung yeu cau. Cung khong chuong trinh nao co the giup cho nguoi sir dung co the tiep can cac thong tin can thiet tir cac tep tren. Vi du. mot nha quan ly luu tru du lieu ve cac nhan vien trong hai tep: - Mot tep luu tru du lieu ve ly lich cua cac nhan vien trong mot ban danh sach thiet lap bang chuong trinh soan thao van ban MS.Word, voi cac muc sau: ho ten, nam sinh. don vi, nghd nghiep, trinh do, ngoai ngu. - Mot tep luu tru dir lieu ve luong, thudng, bao hiem. phuc loi ciia nhan vien thiet lap bang chuong trinh MS.Excel, vdi cac muc: ho ten, don vi, luong, bao hiem. De tim ra cac thong tin lien quan den cac tep khac nhau, ngudi sir dung thudng phai ton rat nhieu thdi gian. Vi du: ngudi quan ly kho cd the tim duoc ngay cac thong tin tra ldi cho cau hoi:"Cho biet ten cac nhan vien cd trinh do dai hoc, ngoai ngu tieng Anh bang C, muc luong cd he sd tren 4" bang cac chuong trinh tren. Ngoai ra he thong quan ly tep con cd nhi£u nhuoc diem khac, vira dan den hien tuong trung lap, du thira du lieu lai vira dan den hien tuong thieu du lieu hoac khdng nhat quan ve du lieu nhu phan trinh bay d muc 5.1. chuong 4. De khac phuc cac han che tren, giai phap tot nhat doi vdi nha quan ly la quan ly du lieu trong cac co sd du lieu. Co sd dir lieu la mot tap hop cac tep co quan he logic vdi nhau, va duoc quan ly theo mot co che thong nhat bang he quan tri co 74 so du lieu, giup cho viec cap nhat va tim kiem thong tin duoc d6 dang va nhanh chong. Vf dui de quan ly du lieu ve cac nhan vien ciia mot don vi nhu trong vf du tren, ta co the xay dung mot co so du lieu bang he quan tri CSDL Foxpro, voi hai tep dir lieu .DBF vdi cac trudng du lieu tuong ung vdi cac muc da neu d tren. Khi do chi bing mot lenh tim don gian, tren man hinh may tinh se hien ra danh sach cac nhan vien dap ung vdi yeu cau dat ra. Nhung van de ly thuyet v6 co sd du lieu se duoc trinh bay d muc 5 - chuong 4. O day can nhan manh viec xir ly co sd du lieu bao gdm ba hoat dong co ban sau: - Cac du lieu can duoc cap nhat thudng xuyen de CSDL luon phan anh hien trang mdi nhat cua td chuc hoac cua cac ddi tuong duoc quan ly. - Viec cung cap thong tin can thiet cho moi ap dung cua ngudi su dung duoc thuc hien thong qua giao dien man hinh chung cua he quan tri CSDL. Ngudi su dung co the chia se sir dung du lieu trong mot CSDL chung. - Ngudi sir dung co the hoi CSDL, yeu cau tao ra cac bao cao nhd sir dung ngon ngu hoi va cac phuong tien lap bao cao do he quan tri CSDL cung cap. Ngudi sir dung se nhanh chong nhan duoc cau tra ldi ve nhung thong tin ma ho yeu cau hoac nhung m iu bao cao hien ra tren man hinh hay in ra tren may Viec quan ly du lieu trong cac CSDL dem lai cho ngudi quan ly nhieu loi ich. Trudc het no giam bdt duoc hien tuong trung lap du lieu va cho phep nhieu ngudi cd the sir dung du lieu trong CSDL. Ngudi sir dung co thd hdi, yeu cau CSDL lap 75 bao cao ma khong phai viet mot chuong trinh. Cac chuong trinh bao dam tfnh doc lap so voi du lieu, tire la co the thay doi du lieu trong bo nho ngoai ma khong cin thay ddi chuong trinh. Tinh ven toan du lieu va an toan du lieu duoc bao dam vi viec truy cap va sira ddi dur lieu duoc kiem soat boi he quan tri CSDL voi cac churc nang quan ly doc lap. Ngay nay CSDL la yeu to khong the thieu duoc ciia moi he thong thong tin. Viec hoc cach sir dung cac phan m£m quan tri CSDL de to churc va khai thac du lieu tro thanh mot yeu cau ddi vdi cac nha quan ly. 76 CHirONG 3 TONG QUAN VE CAC HE THONG THONG TIN Phuong tien truyen ba dau tien cho qua trinh xir ly co chu dich doi voi thong tin la he thong thong tin. He thong nay duoc cau true de thu thap. td chuc, luu trur va hien thi thong tin d tat ca cac dang cua no (du lieu tho. du lieu da duoc giai thich, tri thuc) va cac hinh thuc the hien (van ban, hinh anh, am thanh). Ve nguyen tic moi he thong luu tru va chi din nhu danh ba dien thoai. cac danh muc tra cuu tin... deu co the coi la he thong thong tin. Tuy nhien 6 day ta de cap toi he thong thong tin dien tu. duoc xay dung tren cong nghe thong tin hien dai. He thong thong tin dien tu la hien tuong cua nira sau the ky XX. Su phat trien ciia no gan lien voi nhung tien bo ciia hai cong nghe co ban: mach tfch hop va truyen thong so. Mach tfch hop la cac chip silic chira cac transistor dung de luu tru va xir ly thong tin. Ngay nay mot chip co kha nang luu tru 125.000.000 bytes, tuong duong vdi 14.500 trang sach. Toe do xir ly ciia cac chip vi xir ly dat tdi hang ngan trieu phep toan trong mot giay. De cac he thong thong tin cd the khai thac duoc cac tien bo ky thuat tren. doi hoi phai cd su phat trien tuong ung trong linh vuc phan mem. Dong gop ldn nhat ciia nd la da md ra kha nang sir dung 77 may tinh cho cac ca nhan. Ngay nay nhirng phan mdm ung dung tuyet voi da nang cao vi the ciia may tinh ca nhan. lam cho may tinh ca nhan dung vao vi tri trung tam cua mot mang ludi ciia nhung thiet bi thong minh lien ket nhau. tir dien thoai di dong den TV va cac thiet bi cam tay khac. Dong thoi cac phan mdm quan tri CSDL ra doi va phat trien da lam cho cac CSDL tro thanh mot ngu6n thong tin mdi, mot yeu to trung tam cua moi he thong thong tin. Loi fch ciia may tinh tang len rat nhieu khi chung co the ket noi voi cac may tinh khac de chia se thong tin va xir ly chung. Tir do xuat hien cac mang cuc bo, mang dien rong, dac biet la lien mang thong tin toan cau Internet. Internet, mot phuong tien truy cap thong tin re ti6n va rong khap tir cac may tfnh ca nhan. da giup cho viec luu chuyen thong tin duoc nhanh hon va tu do hon, pha vo moi rao can giura cac quoc gia, dan toe va cac nen kinh te. Cac he thong thong tin ra doi va phat trien tren nen tang do. Ngudi ta phan biet cac loai he thong thong tin theo muc dich ciia no: hd tro cho cac hoat dong quan ly di6u hanh hay ho tro cho hoat dong tac nghiep va dich vu. 1. KHAI NIEM HE THONG He thong co the duoc dinh nghla nhu mot tap hop cac phan tir cd lien he vdi nhau de tao thanh mot tong the chung. Ta co the tim thay nhi£u vf du ve he thong trong vat ly, sinh hoc. trong cong nghe hien dai va trong xa hoi loai ngudi. Vf du: he thong mat trdi va cac hanh tinh, he thong co the con ngudi. he thong loc dau. he thong cac t6 chuc kinh doanh. 78 Tuy nhien dinh nghla nay qua tong quat. Ta dung d day dinh nghla hep hon. phu hop vdi nhu cau mo ta he thong thong tin. He thong la mot tap hop cac phan tu (cac thanh phan) cd lien he vdi nhau. hoat dong de hudng tdi muc dich chung theo cach tiep nhan cac yeu td vao. sinh ra cac yeu td ra. trong mot qua trinh xu ly co td chuc. Nhu vay he thong cd ba thanh phan hay churc nang co ban cd quan he tuong tac vdi nhau: - Dau vao: bao gom cac yeu td duoc thu thap vao he thong de xir ly. Vf du: vat lieu tho. nang luong, du lieu, ngudn nhan lire bao dam cho cac qua trinh xu ly. - X u ly: bao gom cac qua trinh xu ly, che bien de bien cac yeu to vao thanh cac yeu to ra. Vi du: cac qua trinh san xuat, qua trinh ho hap cua con ngudi, qua trinh xir ly du lieu hay cac tinh toan sd hoc. - D au ra: bao gom cac phan tu duoc tao ra tu qua trinh xu ly cho muc dich cuoi cung. Vi du: cac san pham ciia qua trinh san xuat. cac san pham thong tin can chuyen tdi ngudi dung tin. cac ket qua tinh toan. Vi du: Mot he thong san xuat tiep nhan vat lieu tho nhu la dau vao va san xuat ra cac san phaim cuoi cung nhu la dau ra. Mot he thong thong tin cd the coi nhu la mot he thong tiep nhan cac ngudn dir lieu nhu la dau vao va xir ly chung thanh cac san phaim thong tin nhu la dau ra. 79 H inh 15. He thong son xuat Nhap du1 lieu -> XiflyDL Thong tin ra H inh 16. He thong thong tin Ngoai ra ngirdi ta con dira them hai thanh phan lien quan den dieu khien he thong la phan hoi va dieu khien. Mot he thong voi cac thanh phan phan hoi va dieu khien doi khi duoc goi la he thong dieu khien, do la he thong tu kiem tra va tir didu chinh. - P han hoi (hay con goi la lien he nguoc) la du lieu ve sir hoan thanh nhiem vu ciia he thong. Vf du: dir lieu ve doanh thu la phan hoi cho nguoi quan ly viec ban hang. - D ieu kh ien la giam sat va danh gia cac thong tin phan hoi de xem he thong co hoat dong dung huong nhim dat toi muc tieu hay khong. Khi do chuc nang dieu khien phai thuc hien nhirng dieu chinh can thiet doi voi dau vao va qua trinh xir ly de bao bam dau ra thich hop. Vi du: Nguoi quan ly ban hang thuc hien chuc nang dieu 80