Index Types
Unique, index, DUPLICATE, VALUES, ko, PREVENT, karta hai (jaise, email, field, PAR) — INSERT/UPDATE, KOSHISH, karne, PAR, ERROR, THROW, hota hai, AGAR, VALUE, PEHLE, se, EXIST, karti, hai.
TTL (Time-To-Live), index, DOCUMENTS, ko, EK, CERTAIN, TIME, ke, BAAD, AUTOMATICALLY, DELETE, kar, deta hai (jaise, SESSION, DATA, YA, TEMPORARY, LOGS). Geospatial, index, LOCATION-BASED, QUERIES, (jaise, "NEARBY", STORES) ko, SUPPORT, karta hai.
// Unique index:
db.users.createIndex({ email: 1 }, { unique: true });
// TTL index — 3600 seconds (1 hour) ke baad, auto-delete:
db.sessions.createIndex({ createdAt: 1 }, { expireAfterSeconds: 3600 });
// Geospatial index:
db.stores.createIndex({ location: "2dsphere" });
db.stores.find({ location: { $near: { $geometry: { type: "Point", coordinates: [77.5, 12.9] } } } });- Unique index = duplicate values, prevent, karta, hai
- TTL index = documents, ko, automatically, expire/delete, karta, hai
- Geospatial index = location-based ("nearby") queries, ke, liye
Partial, index, sirf, un, documents, ko, index, karta hai, JO, EK, SPECIFIED, filter, condition, MATCH, karte, hain — jaise, sirf, "active" users, ko, index, karna. Index, size, kam, karta hai, aur, WRITE, performance, improve, karta hai.
db.users.createIndex(
{ email: 1 },
{ partialFilterExpression: { status: "active" } }
);Wildcard, index, ($**), UNPREDICTABLE, YA, DYNAMIC, field, names, waale, documents, ke, liye, useful, hai — jaise, EK, "attributes" object, jisme, HAR, product, ke, ALAG, fields, ho, sakte, hain.