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.

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)

DIRTY READ        → reading another transaction's UNCOMMITTED changes (which may roll back)
NON-REPEATABLE READ → re-reading a row gives different values (another txn UPDATED it)
PHANTOM READ      → re-running a query returns different ROWS (another txn INSERTED/DELETED)

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

Level             | Dirty Read | Non-repeatable | Phantom | Concurrency
──────────────────────────────────────────────────────────────────────
READ UNCOMMITTED  | possible   | possible       | possible| highest (least safe)
READ COMMITTED    | prevented  | possible       | possible| (common default)
REPEATABLE READ   | prevented  | prevented      | possible| 
SERIALIZABLE      | prevented  | prevented      | prevented| lowest (most safe)

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

SET TRANSACTION ISOLATION LEVEL SERIALIZABLE;
BEGIN;
  -- ... operations run at the chosen isolation ...
COMMIT;

Inganci na asali

Higher isolation → MORE correctness (fewer anomalies), but MORE locking/contention
                   → lower concurrency, potential slowdowns, more deadlocks
Lower isolation  → MORE concurrency/performance, but risk of anomalies
→ Choose based on the data's needs: financial/critical data may need Serializable;
  most apps use Read Committed (the default) as a balance.
→ Note: implementations vary (MVCC vs locking); the SQL standard defines the levels
  but databases differ in details (Postgres, MySQL/InnoDB, etc.).

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.