Caching Strategies (Redis, Memcached)
Caching stores frequently accessed data in fast storage (memory) to avoid expensive database queries and computations. Django supports multiple cache backends - Redis is the most popular choice for production.
20 min•By Priygop Team•Updated 2026
Django Caching
- Per-view cache - @cache_page(timeout) decorator
- Template fragment cache - {% cache timeout key %}
- Low-level cache - cache.get(), cache.set()
- Cache backends: Redis, Memcached, database, file, locmem
- Redis is recommended for production (fast, persistent)
- Cache invalidation - Clear cache when data changes
- pip install django-redis for Redis backend
Caching Examples
Caching Examples
# settings.py - Redis cache backend
# pip install django-redis
# CACHES = {
# 'default': {
# 'BACKEND': 'django.core.cache.backends.redis.RedisCache',
# 'LOCATION': 'redis://127.0.0.1:6379/1',
# 'TIMEOUT': 300, # 5 minutes default
# }
# }
# Per-view caching
# from django.views.decorators.cache import cache_page
# @cache_page(60 * 15) # Cache for 15 minutes
# def post_list(request):
# posts = Post.objects.filter(published=True)
# return render(request, 'blog/list.html', {'posts': posts})
# Low-level cache API
# from django.core.cache import cache
# def get_popular_posts():
# key = 'popular_posts'
# posts = cache.get(key)
# if posts is None:
# posts = list(Post.objects.order_by('-views_count')[:10])
# cache.set(key, posts, 60 * 30) # Cache 30 minutes
# return posts
# Template fragment caching
# {% load cache %}
# {% cache 600 sidebar %}
# <!-- Expensive sidebar content -->
# {% for cat in categories %}
# <a href="{{ cat.get_absolute_url }}">{{ cat.name }} ({{ cat.post_count }})</a>
# {% endfor %}
# {% endcache %}
# Cache invalidation on save
# @receiver(post_save, sender=Post)
# def clear_post_cache(sender, **kwargs):
# cache.delete('popular_posts')?? Tip
Tip
Use Django's cache framework with Redis or Memcached. cache.set('key', value, timeout=300) for 5-minute cache.
Diagram
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QuerySets are LAZY - no DB hit until evaluated.
?? Common Mistake
Warning
Caching without invalidation strategy. Stale cache causes bugs. Always cache.delete() when data changes.
?? Practice Task
Note
(1) Set up Redis caching. (2) Cache a queryset for 5 minutes. (3) Invalidate cache on model save signal.
Quick Quiz
Key Takeaways
- Caching stores frequently accessed data in fast storage (memory) to avoid expensive database queries and computations.
- Per-view cache - @cache_page(timeout) decorator
- Template fragment cache - {% cache timeout key %}
- Low-level cache - cache.get(), cache.set()