Okwenziwayo - kuyini? I database kuthengiselana

Wokuthengiselana iqoqo izenzo ezithile zazo eyenziwa umuntu noma uhlelo ukufinyelela noma ukuguqula database. Ngaphambi idili, kuthengiselana - ukuthi kudingeka ukuba uqonde okushiwo kule nqubo. Mayelana nencazelo eyisisekelo yegama inqubo itholakala lokuthi ukuthi isenzo kufanele noma ngokugcwele ligcwaliswe noma ukhansele.

Ngamunye kuthengiselana semininingwane kufanele kwisi esimweni esisodwa, okuhambisana kuze kube komunye. Kusolwa ukuthi kungenzeka ukungaguquguquki i- enqubeni.

Abantu abaningi uyazibuza, kuthengiselana - kuyini. Le yunithi umsebenzi wenziwa database. Kungaba ingxenye algorithm jikelele, iqembu ahlukene noma uhlelo lonke.

Okwenziwayo kufanele kuqedwe?

Kunezindlela ezimbili ukuba awuqede yilezi:

• Esimweni lapho okwenziwayo sekuqediwe ngempumelelo, imiphumela alotshwe, futhi database uya kusimo esisha uhambisane (bophezela).
• Uma ukukhishwa okungahambanga kahle, waphenduka iphutha kuthengiselana, it is kukhanselwe. Kulokhu database kumele esimweni kwaba ekuqaleni. Lesi simo sibizwa ngokuthi "buyisela emuva" (ukubuyela emuva). Nokho, uma kuthengiselana ilotshwe, asikwazi kukhanselwe. Uma isenzo kwatholakala ukuthi ayilungile, kubalulekile ukwenza olunye kuthengiselana ukuthi izobuyisa semininingwane isimo kuyavumelana.

izakhiwo ukuthengiselana

Ukumaka umngcele kuthengiselana samukelwa ukusebenzisa opharetha ukuqala umsebenzi, yenza, ukubuyela emuva.

ACID, noma izakhiwo kuthengiselana kungaba kanje:

• Atomic, noma atomicity. Okwenziwayo - kweyunithi indivisible, okumele noma abulawa noma ukhansele.
• Ukuxhumanisa, noma ukungaguquguquki. Okwakushiwo okwenziwayo ukuthi database ihamba komunye umbuso uhambisane kwenye.
• Insulativity, noma atihambi todvwa. Ngamunye kuthengiselana ukuthi wenziwa, akuxhomekile abanye. Zonke imiphumela yenqubo ayatholakala izikhala akufanele kubonakale kwamanye ukuthengiselana.
• Ubude besikhathi, noma isikhathi. Zonke imiphumela eziye izuzwe ngesikhathi kuthengiselana yimpumelelo akufanele elalahlwa ukwehluleka okwalandela. Bayaphepha database unaphakade.

Ukuthengiselana zisetshenziselwa ukwenza izinguquko noma izibuyekezo database. inqubo ngamunye ezilungisiwe kulawulwa umphathi kuthengiselana nemitfombolusito - Imenenja nsiza. Ukuxhumana of abalawuli ezimbili inquma umphumela wokusebenza. ukuthengiselana eyenziwa Ilokhi uma kunesidingo.

isigaba kuthengiselana

Kukhona izigaba ezilandelayo:

• Active. Kulesigaba kuthengiselana kudalwa inqubo iqhaza abaphathi nsiza.
• Preparatory. Phakathi nale nkathi, umphathi isisetshenziswa ngamunye uyakwazi ukunquma umphumela wokusebenza. Ukuqala isigaba kwenzeka uma umqalisi kwenza isicelo ukuze uqedele ukuthenga. Uma umphathi isisetshenziswa akanayo isikhathi sokulungiselela, idinga dispatcher ukuthumela buyisela emuva kuthengiselana. Resource Abaphathi namajenali ukuthi ukurekhoda yonke idatha ikulungele. Lokhu kwenzelwa ukuqinisekisa ukuthi uma kwenzeka ngeziphambeko kwadingeka leli thuba ukuze ngiqhubeke ukusebenza endaweni ethile.
• Nenkanuko edlulele. Ukuqala lokhu simiswe okwamanje lapho bonke abaphathi isisetshenziswa isilungele ukusebenza. Uma kudingeka, dispatcher kuthengiselana singaphetha ukusebenza.

kuthengiselana ngalinye kufanele kuncike nezimfuneko ezithile. Ngenxa yalokho kohlelo ukusebenza kufanele angeniswe isimo lesifanele. Lesi simo kuyadingeka esimweni lapho kukhona ukwehluleka kwamandla.

izingodo kuthengiselana

Phakathi ukusebenza eyenziwa log kuthengiselana, lapho zonke izinguquko elotshiwe. Kuyadingeka ukuba QUNTA njalo, isilinganiso enjengale kuyosisiza ukuba sigweme zichichima. Nokho, kukhona izizathu eziningana kungani akhronimi kungenziwa imisiwe ngalesi sikhathi kubaluleke ngokukhethekile ukuqapha okuqukethwe. Ukuze sinciphise ubukhulu log, ungakwazi ukwenza imisebenzi kancane ngemvume.

Esimeni ilogi ukwehluleka iyingxenye ebalulekile umsebenzi azosiza ukuletha database esimweni kuyavumelana. Umagazini akumelwe zishintshwe noma ukususwa.

Izinzuzo usebenzisa lwamakholi kuthengiselana

Lokhu kwenza kube nokwenzeka ukusekela imisebenzi enjalo:

• ukubuyisela izenzo umuntu;
• alulame ukuthengiselana ezingafakwanga kuphelile;
• ukwenza umqulu isinyathelo phambili ukwehluleka;
• ukwenza ukufanisana emibhalombiko.

Kukanjani akhronimi weligi?

Ngo inqubo Kuncishiswa ikhishwe efayeleni, esetshenziselwa wokuqopha olwengeziwe. Uma sidebeselela le nqubo, sonke isikhala disk ugajwe, futhi kuyoba khona izinkinga eziningi. Ukuze ugweme izimo ezinjalo, lowo akhronimi senzeka ngokuzenzakalelayo, ngaphandle uma imisiwe ngenxa yezizathu ezimele.

Okwenziwayo nge-credit card

Yenza inkokhelo yokukhokha ezitolo, abathengi nicabanga: kuthengiselana - kuyini futhi ziyini na? ukuthengiselana okunjalo nge-credit card njengoba cash ukuhoxiswa, akhawunti ashona, noma ukwenza Ukudluliselwa, ngokuthi kuthengiselana. Lo mqondo isetshenziswa kulesi sibalo ikhadi yokukhokha ku Izitolo okudayisa.

Ukwenza inkokhelo by credit card, akuzona zonke iklayenti uyacabanga ukuthi iziphi izinqubo ezenzeka kulesi sikhathi. Nakuba lolu lwazi kubalulekile ngempela, njengoba sikhuluma imali nokuvikeleka.

Ngakho, umsebenzi - kuyini kulesi sibalo esitolo? Lo msebenzi siqukethe izinyathelo eziningana, okuyinto kuhlobene.

Abahlanganyeli main enqubeni - kuyinto yasebhange (umkhiphi) elikhiphe ikhadi lokukhokha, futhi yasebhange (acquirer), isevisi ezijwayelekile. Ingqikithi yalo msebenzi itholakala lokuthi ukuthi acquirer ufuna ukuthola kusuka imvume Umkhiphi ukuba ukuqhuba ukuthengiselana. Ngokusebenzisa ikhadi nge esibulalayo, ithumela ebethelwe isicelo cashier ngedatha kunesidingo sokuba ukusebenza. Lonke ulwazi oluqukethwe strip magnetic.

Lesi sicelo ithunyelwa processing isikhungo, okuyinto umsebenzi sicubungula futhi ukulethwa alandelayo ulwazi ebhange elikhiphe. It ihlaziya ulwazi bese ucatsanisa tintfo ngayo idatha. Uma kuphakama noma yimuphi ukungavumelani, umkhiphi ayakuphuma umuntu makathole imvume ukuze afeze umsebenzi. Ingqikithi yalo nqubo yokunika ikhodi yokuqinisekisa siqu.

Kwaze kwaba yilapho sebeshiye ukuthi acquirer afeze ukusebenza, okwaphumela izimali isuke kusuka akhawunti yekhasimende umthengisi. Endabeni ka ukwehluleka kudivayisi uzokutshela ukuthi awukwazi ukuqedela okwenzayo.

Okunjalo ukuthengiselana semininingwane kwenziwe ku-inthanethi. Kukhona olunye uhlobo zokukhokhelwa, ngaphandle kwe-intanethi, lapho kukhiqizwa esebenzisa imprinter ukwenza isinyathelo ikhadi.

Abantu abaningi banesithakazelo: noma kungenzeka ukutjhugulula kuthengiselana? Uma kudingekile ibhange angafeza manipulations ezithile ezivumela ukuba benze kanjalo.