ACID Properties
Atomicity — EK, transaction, ke, saare, operations, YA, TOH, SAARE, HONE, CHAHIYE, YA, KOI, NAHI, (all-or-nothing). Consistency — transaction, database, ko, EK, VALID, state, se, DUSRE, VALID, state, mein, LE, jaata hai.
Isolation — CONCURRENT, transactions, EK, dusre, ko, INTERFERE, nahi, karte, JAISE, WOH, ONE-AT-A-TIME, RUN, ho, rahe, hon. Durability — EK, baar, COMMIT, hone, ke, baad, changes, PERMANENT, hain, CHAHE, SYSTEM, CRASH, ho, jaaye.
-- Atomicity example — dono updates, ya to saath, ya, koi, nahi:
START TRANSACTION;
UPDATE accounts SET balance = balance - 100 WHERE id = 1;
UPDATE accounts SET balance = balance + 100 WHERE id = 2;
COMMIT;- Atomicity = all-or-nothing. Consistency = valid, state, se, valid, state
- Isolation = concurrent, transactions, EK, dusre, ko, interfere, nahi, karte
- Durability = committed, changes, permanent, HAIN
Relational, databases, (MySQL) generally, ACID, guarantees, FOLLOW, karte, HAIN — kuch, NoSQL, databases, BASE, (Basically Available, Soft state, Eventual consistency) model, FOLLOW, karte, HAIN, jo, availability, aur, SCALE, ko, PRIORITIZE, karta hai, strict, consistency, se, ZYAADA.
Consistency, sirf, database, CONSTRAINTS, (foreign, keys, etc.) tak, LIMITED, nahi, hai — APPLICATION-LEVEL, business, rules, (jaise, "account, balance, KABHI, negative, nahi, ho, sakta") bhi, TRANSACTIONS, ke, andar, ENFORCE, kiye, jaate, HAIN.