بما يتجاوز cache-aside الأساسي، توجد عدة استراتيجيات تخزين مؤقت — cache-aside و write-through و write-behind و read-through — لكل منها مقايضات مختلفة بين الاتساق والأداء. فهم هذه الاستراتيجيات (وسياسات الإخلاء) يساعدك على تصميم تخزين مؤقت فعال.
Cache-aside (lazy loading — الأكثر شيوعاً)
App checks cache → miss → load from DB → populate cache → return.
✓ Only requested data is cached (efficient); resilient (works if cache is down)
✗ First request is a miss (slower); cache can be stale until TTL/invalidation
→ The default, most common strategy.
Write-through و write-behind
WRITE-THROUGH → write to cache AND DB together (synchronously) on every write
✓ Cache always fresh/consistent ✗ Writes are slower (two writes); caches unread data
WRITE-BEHIND (write-back) → write to cache immediately, write to DB ASYNC later
✓ Fast writes ✗ Risk of data loss if cache fails before the DB write; more complex
