Ntchito yaikulu ya DBMS ndi

Modern Nawonso achichepere machitidwe ntchito pa zinthu zambiri, koma si aliyense amadziwa chomwe iwo ali ndi mmene mungagwiritsire ntchito ntchito Nawonso achichepere. Zida izi ndi nambala yaikulu mwayi, kotero muyenera kudziwa kuti akhoza kuchita ndi zimene lipindulitsa wosuta kuti athe kugwiritsa ntchito iwo.

kasamalidwe deta

Mu malo oyamba, mu ntchito Nawonso achichepere zikuphatikizapo processing wa zinthu m'mutu zakunja nchito imeneyi ndi makonzedwe a nyumba zofunika EP, amene akufunika osati kuti mudziwe sitolo mwachindunji m'gulu Nawonso achichepere komanso kugwira ntchito zosiyanasiyana ofesi, monga kudzuka kudya kupeza owona chilichonse pa nthawi zosiyanasiyana. Mu embodiments ena mwachangu ntchito kuthekera machitidwe osiyana file, pamene ena kupereka ku ntchito, ngakhale pa mlingo wa zipangizo kunja kukumbukira. Koma mu nkhani iyi ndi Dziwani kuti ntchito Nawonso achichepere, ndi digiri yapamwamba ya chitukuko, wosuta, Mulimonsemo, ndi kuwauza kaya dongosolo lililonse ntchito, ndipo ngati ndi choncho, mmene bungwe owona. Makamaka, dongosolo wakhala akuthandiza kuti yake anangotchula zinthu m'gulu Nawonso achichepere.

RAM kasamalidwe gawo lotetezedwa

Mu namtindi wa milandu ntchito Nawonso achichepere ndi wamba kugwiritsa ntchito zinasokoneza makompyuta mwachilungamo voluminous ndi kukula osachepera zambiri zambiri zilipo RAM. Kumene, ngati pa nkhani ya mankhwala wachina chilichonse deta adzakhala umasinthanitsidwa ndi kukumbukira zakunja liwiro yotsirizira udzatithandiza liwiro dongosolo, kotero pafupifupi yekha njira yeniyeni kuti akule deta yake buffering mu RAM. Pankhaniyi, ngakhale opaleshoni dongosolo imapereka dongosolo lonse gawo lotetezedwa, mwachitsanzo kwa UNIX, ndi si zokwanira kuonetsetsa kuti Nawonso achichepere cholinga chachikulu ntchito, monga lili buku wokulirapo deta pa katundu phindu buffering lililonse mbali imodzi ya Nawonso achichepere ntchito. Chifukwa dongosolo chitukuko kuthandiza akonzedwa yakeyake buffers, komanso mwambo wapadera m'malo awo.

Dziwani chakuti pali mzere osiyana machitidwe kulamulira, lolunjika pa kukhalapo mosalekeza mu chikumbukiro cha Nawonso achichepere lonse. malangizo awa abwera kopanda kuti posachedwapa kuchuluka kwa RAM pa kompyuta kuti tiwonjezere kuti sadzakhalanso kudandaula aliyense buffering, ndipo ntchito yaikulu ya mtundu wa Nawonso achichepere pano adzagwa monga mwa nthawi. Pa nthawi, ntchito onsewa adakali mu gawo kuyezetsa.

kasamalidwe ndikupeleka

ndikupeleka ndi ndondomeko ya ntchito ndi ntchito za kasamalidwe dongosolo deta m'munsi amene amachitira monga gulu limodzi. Ngati iwowo kwathunthu anaphedwa bwinobwino, dongosolo analanda kusintha zimene anapanga ndi izo, mu kukumbukira kunja kapena palibe kusintha sadzakhala zimaonekera pa boma la Nawonso achichepere. ntchito kulembapo kuti zithandize zomveka kukhulupirika kwa Nawonso achichepere ntchito. Tikumbukenso kuti ntchito yokonza njira yolondola ya limagwirira ndikupeleka ndi choyambilira ngakhale pamene ntchito limodzi-wosuta Nawonso achichepere, cholinga ndi ntchito yomwe zimasiyana zina kachitidwe.

Chuma kuti ndikupeleka aliyense amayamba okha pa mokhazikika boma Nawonso achichepere chotero masamba mu boma yomweyo pambuyo pa mapeto a ndondomeko, kupanga yabwino kwambiri ntchito ngati unit za ntchito pa Nawonso achichepere. Ndi kasamalidwe koyenera ka wotuluka ziperekedwa mu kufanana ndi dongosolo kulamulira aliyense wosuta munthu, mfundo, akhoza kumva mbali ya lonse. Komabe, izi mu njira ina ndi chifaniziro idealized, monga zinthu zambiri pamene anthu ntchito akadali amaonanso anzake ngati ntchito dongosolo multiuser, koma kwenikweni amatipatsa kwambiri mfundo Nawonso achichepere. Nchito monga Nawonso achichepere Mipikisano wosuta wakhalanso kugwirizana ndi mfundo ndikupeleka kasamalidwe monga dongosolo siriyo kuphedwa, ndi serialization.

Kodi chiyani?

Serializing kufanana executable ndikupeleka kumaphatikizapo pomanga wapadera Achiwembu chawo ntchito, mmene zotsatira okwana akwaniritsa ndi lofanana chifukwa analandira osakaniza, chifukwa cha kuphedwa awo yotsatana.

Siriyo kuphedwa dongosolo ndi dongosolo enieni kanthu, imbaenda serialization. Kumene, ngati dongosolo analandira kupereka moona A kuphedwa siriyo wa wotuluka osakaniza, ndiye wosuta aliyense amene kwaiye ndikupeleka, pamaso pa anthu ena adzakhala imperceptible mwamtheradi, koma kuti ntchito pang'ono pang'onopang'ono poyerekeza mode osakwatiwa-wosuta.

Pali zina zazikulu serialization aligorivimu. M'magulu centralized, wotchuka kwambiri masiku ano ndi ma aligorivimu kuti ndi zochokera kalunzanitsidwe adani zinthu zosiyana Nawonso achichepere. Pankhani ya aligorivimu aliyense serialization amapereka kuthekera kwa mkangano wotuluka awiri kapena kuposera kupeza zinthu zina Nawonso achichepere. Zikatere, kuthandiza njirayi, muyenera falitsani kumbuyo, ndiyo kuthetsa kusintha opangidwa ndi Nawonso achichepere ndi ndondomeko umodzi kapena kuposerapo. Ichi ndi chimodzi chabe mwa mavuto kumene dongosolo Mipikisano wosuta, amamva pagulu.

kudula mitengo

Chimodzi mwa zofunika zazikulu kachitidwe kamakono ndi kuonetsetsa kuti kudalirika kwa yosungirako zinthu m'mutu kunja. Makamaka, ithandiza kuti imodzi mwa ntchito zazikulu za Nawonso achichepere komanso kuthekera kuti achire otsiriza coherent boma la Nawonso achichepere pambuyo pakutchulidwa pulogalamu kapena hardware aliyense kulephera. Mu namtindi wa milandu anatengedwa kuti asadziphe awiri zolephera hardware:

• zofewa, amene angathe kutanthauziridwa monga amasiya mwadzidzidzi kompyuta (choncho ambiri - Emergency Mphamvu Off);
• okhwima, amene yodziwika ndi imfa tsankho kapena wathunthu deta kusungidwa pa TV kunja.

Monga pulogalamu zolephera Zitsanzo dongosolo mwadzidzidzi shutdown pamene anayesa kugwiritsa ntchito mwawi kuti imodzi mwa ntchito yaikulu DBMS sali m'gulu kapena osaitanidwa zofunikira aliyense wosuta, umene ndi nkhani zina siinamalizidwe. The vuto woyamba kuonedwa ngati mtundu wapadera kulephera zofewa, pamene vuto la inawo M'pofunika kuthetsa mavuto a ndikupeleka limodzi.

Ndithudi, Mulimonsemo apeze yachibadwa Nawonso achichepere m'pofunika kukhala ndi kuchuluka kwa mfundo zina. M'mawu ena, pakuti kukonza yachibadwa zodalirika yosungirako posonkhanitsa deta Nawonso achichepere muyenera kuonetsetsa redundancy yosungirako zambiri, ndi gawo la deta ntchito kuchira ayenera kulondera mosamala. The njira yofala kuonetsetsa yokonza deta kuthetsa, ankaona kuti mitengo kusintha.

ndi nanga kugwiritsa ntchito chiyani?

Magazini ndi gawo lapadera la Nawonso achichepere, amene kufika angapo ntchito Nawonso achichepere sali m'gulu, ndipo anakhalabe mosamala kwambiri. Nthawi zina, ngakhale pa nthawi yomweyo amatithandiza kuti mabuku awiri a magazini, pa TV osiyana thupi. Mu sitolo analandira zokhudza kusintha kulikonse komwe kumachitika mu Mbali yaikulu ya Nawonso achichepere, ndi machitidwe osiyana ulamuliro Kusintha zinthu journaled mbali zosiyanasiyana. Nthawi zina, ndi kulowa chipika amadziwa oyenerera makamaka mfundo opareshoni kusintha, kwinakwake - osachepera mkati ntchito kugwirizana ndi kunja kusinthidwa kukumbukira tsamba, pamene ena DBMSs idzagwiritsa ntchito osakaniza njira ziwiri.

Mulimonsemo, otchedwa "njira ya kujambula chisanadze emptive" mu magazini. Mu ntchito mbili yake zikuonetsa kusintha chinthu chilichonse Nawonso achichepere igwera mu kukumbukira kunja magazini pamaso chinthu variable. Amadziwika kuti ngati ntchito Access Nawonso achichepere zikuphatikizapo zoletsedwa wabwinobwino ndi protocol ichi, pogwiritsa ntchito magazini kuthetsa mavuto alionse okhudzana kuchira Nawonso achichepere mu chochitika cha zolakwa iliyonse.

angadzachite

The vuto losavuta ndi kubwezeretsedwa kwa ndikupeleka mmodzi kukunkhuniza. Kwa njirayi, si koyenera kuti ntchito dongosolo lonse chipika kusintha, ndipo zokwanira ntchito iliyonse ndikupeleka m'dera ntchito magazini kusinthidwa, kenako falitsani kumbuyo ndikupeleka akamadzapereka ntchito ya osiyanitsidwa, kuyambira kumapeto kwa aliyense umboni. Kapangidwe ka ntchito Nawonso achichepere kumafuna kugwiritsa ntchito chabe eg zimenezi, koma nthawi zambiri mitengo kumeneko akugwiritsabe sagwirizana ndi rollback ngakhale munthu wa wotuluka munthu ikuchitika mwa dongosolo lonse, ndi kuti zolembedwa zonse za kumulipiritsa ophatikizana n'zosiyana mndandanda.

Mu chochitika cha yofewa kulephera kunja kukumbukira Nawonso achichepere zikuphatikizapo zinthu zosiyanasiyana kuti akhala kusinthidwa ndi wotuluka si anamaliza nthawi yatsoka kulephera, ndipo pasakhale zinthu zosiyana, akweza amene anali bwinobwino pamaso vuto pogwiritsa ntchito nkhani RAM gawo lotetezedwa amene kwathunthu Mwamsanga pamene pali mavuto ofanana. Ngati protocol ndi kumvera, kupereka ntchito ya m'magazini m'deralo kwenikweni kulemba kukumbukira zakunja zimene ikukhudzana bwanji ndi zosintha zinthu ngati zimenezo.

Cholinga cha ndondomeko kuchira pambuyo pakutchulidwa za kulephera zofewa amatanthauza kukumbukira kunja kwa Nawonso achichepere waukulu, umene mudzatuluka zinachitikira akukonzekera mu EaP kusintha kulikonse kwa ndikupeleka anamaliza ndipo chotero adzafunika mulibe kuda njira chosakwanira. Kuti tikwaniritse zotsatira zimenezi, akuluakulu Nawonso achichepere ntchito ndi mu nkhani iyi, rollback wotuluka uncommitted, kubwereza opaleshoni, zotsatira za zomwe pamapeto pake siziwoneka ku kukumbukira kunja. pochita zimenezi ndithu zambiri subtleties, amene makamaka ikukhudzana bwanji ndi gulu la kasamalidwe magaziniyo komanso buffers.

zolephera Mwakhama

Ngati ndi kotheka, kubwezeretsa Nawonso achichepere pambuyo pakutchulidwa zakulephera zovuta si magazini, komanso Nawonso achichepere kubwerera. Yotsirizira n'zimene wathunthu wa Nawonso achichepere pa nthawi imeneyo ngati magazini anayamba kudzaza. N'zoona kuti ndondomeko yachibadwa kuchira amafuna magazini chitetezo Choncho, monga taonera kale, kuti atetezedwe zake kukumbukira kunja woyikidwa amafuna okhwima kwambiri. Pankhaniyi, ayambe Nawonso achichepere ndi kuti, kuchokera m'mabaibulo archival magazini ndi ankaimba wotuluka onse imachitika anamaliza pa nthawi ya tsoka. Ngati ndi kotheka, iwo akhoza ngakhale idzaseweredwe ntchito chosakwanira wotuluka ndi kupitiriza ntchito zawo pakutha pa ndondomeko kuchira, koma kachitidwe kwambiri weniweni, ndondomeko otere osati ikuchitika chifukwa palokha kuchira pambuyo kulephera zovuta ndi ndondomeko ndi yaitali.

chilankhulo Support

Ntchito ndi zinasokoneza makompyuta amakono ntchito zinenero zosiyanasiyana, ndi Nawonso achichepere oyambirira amaikidwa, ntchito ndi makhalidwe ena amene zimasiyana dongosolo masiku popereka thandizo apadera zinenero angapo. Awa anali makamaka SDL ndi DML, anafuna chimatanthauza Nawonso achichepere chithunzithunzi ndi deta mpheto, motero.

SDL ntchito kutifotokozera kapangidwe zomveka wa Nawonso achichepere, ndicho, kuzindikira dongosolo enieni Nawonso achichepere, umene ulipo kwa owerenga. DML mulinso ya ntchito mpheto mauthenga, limakupatsani kusunga zinthu Nawonso achichepere ndi, komanso kuchotsa, kusintha kapena kugwiritsa ntchito deta zilipo.

DBMS mbali monga mitundu yosiyanasiyana ya chithandizo chinenero umodzi Integrated kuti amapereka zinthu zonse zofunikira ntchito wabwinobwino wa zinasokoneza makompyuta, chilengedwere koyamba, ndipo amapereka wosuta mawonekedwe muyezo. The chinenero muyezo umene amapereka ntchito yaikulu ya Nawonso achichepere ambiri m'masiku athu kachitidwe ubale ntchito ndi SQL.

Ndi chiyani icho?

Mu malo oyamba chinenero Chili ntchito yaikulu ya DML ndi SDL, ndiye amatipatsa kuthekera kudziŵa manenedwe yeniyeni ya Nawonso achichepere ubale ndi kusintha zofunika. Choncho osiyana zinthu anangotchula Nawonso achichepere anathandiza mwachindunji pa mlingo chinenero m'lingaliro kuti kutembenuka imachitidwa ndi kompayila maina chinthu identifiers awo mkati, zochokera anathandiza matebulo utumiki mwapadera-akalozera. Phata la dongosolo kulamulira, mfundo, si kucheza ndi matebulo kapena mizati payekha.

The chinenero SQL zikuphatikizapo mndandanda wa zida wapadera kuthandauza zopinga Nawonso achichepere. Kachiwiri, aliyense malamulo otere amakhala mu magome wapadera, Catalogs ndiponso kukhulupirika polojekiti ikuchitika mwachindunji pa mlingo chinenero, kuti ali m'kati kuwerenga payekha Nawonso achichepere kusinthidwa mawu kompayila, zochokera likupezeka mu Nawonso achichepere zopinga kukhulupirika, amathera kupanga malamulo kake.