Redis என்பது in-memory இருந்தாலும், disk-க்கு data persist செய்து data restarts-ஐ தாங்கி நிற்கும். இது இரண்டு mechanisms வழங்குகிறது — RDB (point-in-time snapshots) மற்றும் AOF (append-only log of operations) — வெவ்வேறு durability/performance trade-offs உடன்.
RDB — point-in-time snapshots
RDB takes SNAPSHOTS of the dataset at intervals, saving a compact binary file.
✓ Compact single-file backups; fast restarts (load the snapshot)
✓ Good for backups and disaster recovery; less impact on performance
✗ You can LOSE data since the last snapshot (e.g. last few minutes) if Redis crashes
→ Configure save points: e.g. "save after 900s if ≥1 change, 300s if ≥10 changes"
