Shard Keys
Shard, key, EK, FIELD, (YA, FIELDS) hai, JO, DECIDE, karta hai, ki, DATA, DIFFERENT, SHARDS, ke, BEECH, KAISE, DISTRIBUTE, hoga — EK, ACHHI, SHARD, KEY, HIGH, CARDINALITY, (BAHUT, saare, UNIQUE, VALUES) aur, EVEN, DISTRIBUTION, RAKHTI, hai.
"MONOTONICALLY, INCREASING" shard, keys, (jaise, timestamp) "HOTSPOTTING" ka, CAUSE, ban, sakte, HAIN — SAARE, NAYE, WRITES, EK, HI, SHARD, PAR, JAATE, HAIN, JISSE, WOH, SHARD, OVERLOADED, ho, jaata hai.
// Achhi shard key — high cardinality, well-distributed:
sh.shardCollection("myDatabase.orders", { customerId: "hashed" });
// Bad shard key — monotonically increasing (hotspotting risk):
// sh.shardCollection("myDatabase.orders", { createdAt: 1 });- Shard key = field, jo, data, distribution, DECIDE, karta, hai, shards, ke, beech
- High cardinality + even distribution = achhi, shard, key, ki, PROPERTIES
- Monotonically increasing keys (timestamp), "hotspotting" ka, RISK, hain
EK, shard, key, MULTIPLE, fields, se, ban, sakti, hai — jaise, { region: 1, userId: 1 } — YE, EVEN, distribution, deta, hai, AUR, region-based, queries, ko, bhi, EFFICIENT, banaता, hai (targeted, queries).
sh.shardCollection("myDb.orders", { region: 1, customerId: 1 });MongoDB, 4.2+, mein, shard, key, VALUE, ko, update, kiya, ja, sakta hai (PEHLE, IMMUTABLE, tha) — LEKIN, ISKA, MATLAB, DOCUMENT, EK, shard, se, DUSRE, mein, MOVE, ho, sakta hai, JO, EK, EXPENSIVE, operation, hai. Shard, key, choose, karте, waqt, ISE, DHYAAN, mein, rakho.