#databaseoptimization

Sahn Lam @sahnlam

Caching 101: The Must-Know Caching Strategies Fetching data is 𝘀𝗹𝗼𝘄. Caching speeds things up by storing frequently accessed data for quick reads. But how do you populate and update the cache? That's where strategies come in. 🔍 Read Strategies: 𝗖𝗮𝗰𝗵𝗲 𝗔𝘀𝗶𝗱𝗲 (Lazy Loading) - How it works: Tries cache first, then fetches from DB on cache miss - Usage: When cache misses are rare or the latency of a cache miss + DB read is acceptable 𝗥𝗲𝗮𝗱 𝗧𝗵𝗿𝗼𝘂𝗴𝗵 - How it works: Cache handles DB reads, transparently fetching missing data on cache miss - Usage: Abstracts DB logic from app code. Keeps cache consistently populated by handling misses automatically 📝 Write Strategies: 𝗪𝗿𝗶𝘁𝗲 𝗔𝗿𝗼𝘂𝗻𝗱 - How it works: Writes bypass the cache and go directly to the DB - Usage: When written data won't immediately be read back from cache 𝗪𝗿𝗶𝘁𝗲 𝗕𝗮𝗰𝗸 (Delayed Write) - How it works: Writes to cache first, async write to DB later - Usage: In write-heavy environments where slight data loss is tolerable 𝗪𝗿𝗶𝘁𝗲 𝗧𝗵𝗿𝗼𝘂𝗴𝗵 - How it works: Immediate write to both cache and DB - Usage: When data consistency is critical 🚀 Real-Life Usage: 𝗖𝗮𝗰𝗵𝗲 𝗔𝘀𝗶𝗱𝗲 + 𝗪𝗿𝗶𝘁𝗲 𝗧𝗵𝗿𝗼𝘂𝗴𝗵 This ensures consistent cache/DB sync while allowing fine-grained cache population control during reads. Immediate database writes might strain the DB. 𝗥𝗲𝗮𝗱 𝗧𝗵𝗿𝗼𝘂𝗴𝗵 + 𝗪𝗿𝗶𝘁𝗲 𝗕𝗮𝗰𝗸 This abstracts the DB and handles bursting write traffic well by delaying sync. However, it risks larger data loss if the cache goes down before syncing the buffered writes to the database. – Subscribe to our weekly newsletter to get a Free System Design PDF (158 pages):