#Bayanai

52 tambayoyi

SQL nini ne kuma ana yi amfani da shi?SQL#databaseJunior
NULL ina amfani ta yaya a cikin SQL?SQL#databaseJunior
Menene Primary keys da Foreign keys?SQL#databaseMiddle
Menene ƙuntatawa na database?SQL#databaseMiddle
Menene normalization na database?SQL#databaseMiddle
Mene ne huluffin jeri da ACID properties?SQL#databaseMiddle
Menene kalmomin gida da kalmomin gida masu aiki?SQL#databaseMiddle
Jigogee Isolation Levels sunan rufe? **Isolation levels** suna kontrola yadda jigogee (transactions) da ke aiki lokaci gida za su iya ganin canja-canja na juna na ba-karanta (ko na aiki) — suna saida **daidaituwa** akasin **aiki/haɗi**. Isolation mafi girma ya iya dakatar da anomalies da yawa amma yana kara kulle/rarrabawa. ## Concurrency anomalies (abin da isolation ya dakatar) [[CODE_1]] Waɗannan su ne matsalolin da zasu iya faruwa idan jigogee suna aiki a lokaci gida — isolation levels suna kontrola waɗanda aka dakatar. ## Dibbin hudu na isolation levels na standard [[CODE_2]] Kowanne matakin sama yana dakatar da anomalies da yawa. **Read Committed** shine babbar zaɓi (yana dakatar da dirty reads); **Serializable** shine mafi muni (jigogee suna aiki kamar ba lokaci gida ba) amma ya bukaci haɗi. ## Saita isolation level [[CODE_3]] ## Inganci na asali [[CODE_4]] ## Me ya sa ya bukaci Isolation levels na jigogee su ne mahimman ilimi na gida don fahimtar **concurrency a cikin databases** — lokacin da jigogee masu yawa suka yi aiki a lokaci gida (kamar yadda suke aiki a kowane aikace-aikacen masu mai users), isolation levels suna ƙayyade inganci-daidaituwa da aiki, don haka fahimtar su ya bukaci don gina aikace-aikacen daidai, aiki da haɗi. Ribobbin mahimman abubuwa su ne **concurrency anomalies** (dirty reads, non-repeatable reads, phantom reads — matsalolin da ke faruwa idan jigogee suka ga canja-canja na juna) da kuma yadda **dibbin hudu na isolation** (Read Uncommitted, Read Committed, Repeatable Read, Serializable) suna ƙare-ƙare dakatar da su. Fahimtar haka ya bukaci ga daidaituwa: zaɓin isolation mabas za ya iya ƙaushe anomalies da zasu ɓata bayanai ko samar da sakamakon ba daidai (alal misali karanta bayanai ba-karanta da jiya suka dogara, ko karanta ba-jiya), amma zaɓin sama yana rage haɗi da aiki. Babbattiyar **inganci na asali** — isolation sama yana nufin daidaituwa da yawa amma kulle/rarrabawa da yawa (haɗi mabas, saurin jiya karasa da deadlocks), isolation mabas yana nufin aiki amma haɗari na anomalies — shine masaniyar mahimma: kinka zaɓi matakin bisa abin da bayani ke buƙatar (bayanai na mahimmanci/kuɗi na iya bukatar Serializable; jumhuriyar aikace-aikace suna amfani da Read Committed a matsayin daidaituwa). Sanin cewa abubuwan suna bambanta (MVCC akasin kulle) ya bukaci ma. Tun concurrency yana nan a gaida a cikin aikace-aikace na bayani na ainihi, da tun isolation levels suna ƙayyade daidaituwa-mahimma tsakanin daidaituwa da aiki (zaɓin ba daidai zai kawo da anomalies ko aiki matsaloli), fahimtar isolation levels — anomalies, matakin, da inganci-da-concurrency trade-off — shi ne ilimi na babbar matakin da ke bukaci don gina daidai, aiki da haɗi da cikakke da gida jiya kaɗai gajiya ne na interviews.
Me ke haifar da deadlocks kuma me ne za ka yi don kawar da su?SQL#databaseSenior
Ainihin stored procedures da kuma yaushe ya kamata ka yi amfani da su?SQL#databaseSenior
DDL, DML, DCL da TCL menene?SQL#databaseSenior
Wadanne jerin nau'in bayanan SQL da kuma yaya za ka zaɓi su?SQL#databaseMiddle
PostgreSQL menene kuma me ya sa a zaɓa shi?PostgreSQL#databaseJunior
Wane nau irin siffofin bayyanar lissafi da PostgreSQL ke ba'a gida da standard SQL?PostgreSQL#databaseJunior
psql menene kuma abin mahimman umarnin sa ne?PostgreSQL#databaseJunior
Yaya auto-incrementing IDs ke aiki (SERIAL, sequences, IDENTITY)?PostgreSQL#databaseJunior
Menene schemas a cikin PostgreSQL?PostgreSQL#databaseJunior
Yaya suna aiki array columns a PostgreSQL?PostgreSQL#databaseJunior
Menene stutun sarrafi?PostgreSQL#databaseJunior
JSONB yaya ta aiki kuma yaushe za ka yi amfani da ita?PostgreSQL#databaseMiddle
Yaya full-text search ke aiki a cikin PostgreSQL?PostgreSQL#databaseMiddle
Menene MVCC a PostgreSQL?PostgreSQL#databaseMiddle
PostgreSQL extensions nima ne?PostgreSQL#databaseMiddle
LISTEN da NOTIFY menene?PostgreSQL#databaseMiddle
Wadanne sharukodin da PostgreSQL ke goyo?PostgreSQL#databaseMiddle
Locking yana aiki ta yaya a PostgreSQL?PostgreSQL#databaseSenior
MongoDB me ne ce a yaya ya bambanta da SQL databases?MongoDB#databaseJunior
Menene dokumennin da tarin-mallakat a MongoDB?MongoDB#databaseJunior
BSON menene kuma nawa ne nau'ukan bayani da MongoDB ke goyan?MongoDB#databaseJunior
Menene MongoDB shell (mongosh) da mahimman grayansa?MongoDB#databaseJunior
Nawa ciki yayi aiki cikin MongoDB?MongoDB#databaseMiddle
Yadda suke aiki jujjuyawa a MongoDB?MongoDB#databaseMiddle
Mongoose shine nee da me yace ODM?MongoDB#databaseMiddle
Schema validation yadda yake aiki a MongoDB?MongoDB#databaseMiddle
Change streams nima ne?MongoDB#databaseSenior
Yaya write concern da read concern ke shafar jiya?MongoDB#databaseSenior
Menene Redis kuma mene ne aka yi da shi?Redis#databaseJunior
Wadansu nau'ikan data da Redis ke goyo?Redis#databaseJunior
Nawa gutsuttsuttukan gida da baba suke aiki a Redis?Redis#databaseJunior
Yaya tsira (TTL) ke aiki a Redis?Redis#databaseJunior
Redis jeri nawa ke aiki kuma anayi amfani da su ta yaya don jeri-jeri na aiki?Redis#databaseJunior
Redis hashes da sets suna aiki na yaya?Redis#databaseJunior
Menene saitunan da aka tsara da kuma ana amfani da su?Redis#databaseJunior
redis-cli menene da ainihin ayyukansa?Redis#databaseJunior
Redis ya bambanta ta yaya daga gida na data na gida?Redis#databaseJunior
Kedànniyar Redis ta aiki ta yaya (RDB vs AOF)?Redis#databaseMiddle
Redis ma'amaloli suna aiki ta yaya?Redis#databaseMiddle
Yaya Redis aiki ne atomike kuma me yasa ya matukaici?Redis#databaseMiddle
Lua scripting a Redis yaya ke aiki?Redis#databaseSenior
Wane ƙarin tsarin bayanan Redis da modules da ke akwai?Redis#databaseSenior
Amazon DynamoDB nini?Cloud & AWS#databaseMiddle
Yaya kuke optimize mara fiɗi kasuwar bayanai?Site Reliability & Operations#databaseMiddle