Isolation Levels
READ UNCOMMITTED — sabse, LOOSE, level, — "DIRTY, READS" possible, hain (uncommitted, changes, dikh, sakte, HAIN). READ COMMITTED — sirf, committed, data, dikhta, hai. REPEATABLE READ — MySQL, ka, DEFAULT, — ek, transaction, ke, andar, SAME, query, HAMESHA, SAME, results, deti, hai.
SERIALIZABLE — sabse, STRICT, level, — transactions, EFFECTIVELY, sequentially, run, hote, hain (KAAFI, SLOW, LEKIN, MAXIMUM, safety).
SET TRANSACTION ISOLATION LEVEL REPEATABLE READ;
START TRANSACTION;
SELECT balance FROM accounts WHERE id = 1;
-- ... kuch, aur, kaam ...
SELECT balance FROM accounts WHERE id = 1; -- SAME result, chahe, kisi, aur, ne, update, kiya, ho
COMMIT;- READ UNCOMMITTED (loosest) → SERIALIZABLE (strictest)
- REPEATABLE READ = MySQL, ka, default, isolation, level
- Stricter, isolation, = safer, LEKIN, kam, concurrency (slower)
Phantom, read, TAB, HOTA, hai, jab, EK, transaction, EK, hi, query, DO, baar, RUN, karta hai aur, DIFFERENT, number, of, rows, milte, hain (kyunki, DUSRE, transaction, ne, NAYI, rows, INSERT, ki), — SERIALIZABLE, isolation, level, ISKO, PREVENT, karta hai.
Financial, applications, mein, STRICTER, isolation, (SERIALIZABLE, YA, REPEATABLE READ) prefer, ki, jaati, hai. High-throughput, applications, jahaan, KUCH, INCONSISTENCY, TOLERABLE, hai, wahaan, READ COMMITTED, BETTER, performance, de, sakta, hai.