सही डेटाबेस छनोट गर्नु एक मुख्य सिस्टम-डिजाइन निर्णय हो — SQL (relational) र NoSQL प्रकारहरू (document, key-value, आदि) को बीचमा, डेटा, पहुँच प्याटर्न, स्केल, र स्थिरता आवश्यकताको आधारमा। विभिन्न डेटाबेसहरू विभिन्न आवश्यकताहरूको लागि उपयुक्त हुन्छन्।
SQL बनाम NoSQL (मुख्य छनोट)
SQL (relational: PostgreSQL, MySQL) → structured data, tables, relationships, ACID:
✓ strong consistency, complex queries/joins, transactions, well-defined schema
✓ for: relational data, transactions, complex queries (most traditional apps)
NOSQL → various non-relational models, flexible schema, often easier horizontal scaling:
→ DOCUMENT (MongoDB) → flexible JSON-like docs
→ KEY-VALUE (Redis, DynamoDB) → simple, fast lookups, caching
→ WIDE-COLUMN (Cassandra) → massive scale, high write throughput
→ GRAPH (Neo4j) → relationships/networks
✓ for: flexible schema, huge scale, specific access patterns, high throughput
