Menene kalmomin gida da kalmomin gida masu aiki?

Question

IT Interview Practice · Accepted Answer

A **kalmo** (view) shi ne tambaya da aka ajiye wacce ke aiki kamar teburin rufe — kana buguwar ta kamar teburi, amma kana gudawar da tambayan da ke karkashi kowane lokaci. A **kalmo masu aiki** (materialized view) yana ajiye sakamakon tambayan *sakamakon* da aka gida (ana sake sabunta sauran lokuta), gina juyayi na sarkakiya don saurin karantawa.{{LINEBREAK}}{{LINEBREAK}}## Kalmon na yau-a-ran — tambaya da aka ajiye{{LINEBREAK}}{{LINEBREAK}}```sql
-- define a view
CREATE VIEW active_users AS
SELECT id, name, email FROM users WHERE active = true;

-- query it like a table — it runs the underlying SELECT each time
SELECT * FROM active_users WHERE name LIKE 'A%';
```{{LINEBREAK}}{{LINEBREAK}}Kalmo shine **teburin rufe** — ba ta ajiye bayani da kanta ba, kawai ma'anar tambayan. Kowane lokaci da kake bugawa kalmo, tambayan da ke karkashi na aiki akan bayanan yanzu (kullun sabo).{{LINEBREAK}}{{LINEBREAK}}## Me yasa aka yi amfani da kalmomin{{LINEBREAK}}{{LINEBREAK}}```text
✓ SIMPLIFY complex queries — encapsulate a complex JOIN/aggregation as a named view
✓ ABSTRACTION — present a clean, stable interface; hide underlying table complexity
✓ SECURITY — grant access to a view exposing only certain columns/rows (hide the rest)
✓ REUSABILITY — define common query logic once, reuse it everywhere
✓ Consistency — everyone uses the same definition of "active_users"
```{{LINEBREAK}}{{LINEBREAK}}Kalmomin suna da kyau don rufe ilimin hadaddiya, samar da abin juriya masu daidai akan teburun, da tsaron bayani (fallasa bayani na musamman kawai).{{LINEBREAK}}{{LINEBREAK}}## Kalmomin masu aiki — sakamakon da aka ajiye{{LINEBREAK}}{{LINEBREAK}}```sql
-- stores the RESULTS physically (precomputed) for fast reads
CREATE MATERIALIZED VIEW monthly_sales AS
SELECT month, SUM(amount) AS total FROM orders GROUP BY month;

SELECT * FROM monthly_sales;        -- fast — reads stored results, doesn't recompute
REFRESH MATERIALIZED VIEW monthly_sales;   -- update the stored data when needed
```{{LINEBREAK}}{{LINEBREAK}}A **kalmo masu aiki** yana ajiye sakamakon tambayan da gida — don haka karantawa shine sauri (babu sake lissafin), amma bayanan ba ta da sabuntawa fiye da `REFRESH` na karshe. Daidai ne don haɓakar haɗi wajen abubuwan buguwa sau-sau amma suke jure gatari.{{LINEBREAK}}{{LINEBREAK}}## Kalmo da kalmon masu aiki juyayya{{LINEBREAK}}{{LINEBREAK}}```text
View              → always FRESH, but re-runs the query each time (slower for complex queries)
Materialized view → FAST reads (precomputed), but data can be STALE until refreshed
→ Use views for abstraction/simplification; materialized views for caching expensive
  query results that are read often and don't need real-time freshness.
```{{LINEBREAK}}{{LINEBREAK}}## Me yasa ya matukar mahimmanci{{LINEBREAK}}{{LINEBREAK}}Kalmomin kalmomin gida ne abubuwan amfani don **aiki, saukar saukar, da tsaron bayani**, kuma fahimtar su (da kalmomin masu aiki) yana da nilai don shirye-shiryen kuma optimetun sirir bayani.{{LINEBREAK}}{{LINEBREAK}}Kalmon na yau-a-ran **kalmomin** (tambayoyin da aka ajiye suke aiki a matsayin teburun rufe) suna samar da ayodin gida: saukar tambayoyin hadaddiya (rufe ilimtan hadari JOIN/aggregations a matsayin kalmo da aka suna da kare), samar da abin juriya masu daidai akan teburun (don haka lambar aikacin ko wasu tambayoyin suke amfani da juyayyar gida), bayyana **tsaro** (ba da yarjejeyin da kalmo wacce ta fallasa kawai wasu rubutu/layi yayin boye bayanan da siri), da mikirira maimaitawa (bayyana ilmin tambayan gida sau ɗaya).{{LINEBREAK}}{{LINEBREAK}}Waɗannan suna sa kalmomin ƙarami don haɗaɗɗe, tsaron aiki da teburun. **Kalmomin masu aiki** suna magance bukatar daban — **karfi**: ta ajiye sakamakon tambayan da aka riga aka lissafi (ana sake sabunta sauran lokuta), suna sa karantawa haddi mai tsada, a wurin sababbin datiya.{{LINEBREAK}}{{LINEBREAK}}Fahimtar **juyayyar** — kalmomin na yau-a-ran kullun sabo amma aiki ya sake tambayan kowane lokaci, yayin da kalmomin masu aiki sune sauri amma zasu iya zama da tsofaffi har sai na sabunta — yana mahimmanci don zaɓin daidai (kalmomin don aiki/saukar saukar, kalmomin masu aiki don saita haddi karfi, abubuwan buguwa sau-sau da suke jure gatari).{{LINEBREAK}}{{LINEBREAK}}Tunda shirye-shiryen ilimin tambayan (kalmomin don aiki da tsaro) da optimetun haddin haddi (kalmomin masu aiki don saita haddi karfi) sune bukatu na gida a aiki da teburun, kuma tunda fahimtar nuni biyu da juyayya su ta karfi/karfi tana taimaka muku a yi amfani da su daidai, sanin kalmomin da kalmomin masu aiki yana da amfani, abin da ke da lahani don karar abubuwan da za su ɗauki, aiki mai karfi da tsaro na sirir bayani.

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