MongoDB index/RAM relationship

Question

I\'m about to adopt MongoDB for a new project and I\'ve chosen it for flexibility, not scalability so will be running it on one machine. From the documentation and web posts

Answer 1

MongoDB keeps what it can of the indexes in RAM. They'll be swaped out on an LRU basis. You'll often see documentation that suggests you should keep your "working set" in memory: if the portions of index you're actually accessing fit in memory, you'll be fine.