All aboard the Data Express! Let’s imagine our database as this massive train station. The trains are packed with information – from passengers’ details to the schedules. Every time you want to know when the next train to DevOps Land is, you have to ask the station master (the database). If too many folks keep asking the same question, the station master will get tired, slowing down the whole operation. So, what do we do? Enter: Caching!
Read on for different caching mechanisms in several major relational databases, various reasons for external caches (like Redis and memcached) to exist, and four patterns for external caching. I’ve found that database people tend not to care much about external caches, leaving that to application developers. But there can be good reasons to store high-read, low-write data in caches, reducing some of the strain on those expensive database servers.