Introduction to LSM Trees: May the Logs Be with You
This idea of storing data into append only logs is the basic idea behind data structures like SSTables and LSM Trees which power many databases like Casandra, RockDB etc. If we try to define an LSM Tree, we can go something like:
An LSM Tree or “Log Structured Merge Tree” is a data structure with performance characteristics that make it very attractive to store data with high insert and update rates. LSM trees are based on a simple and yet powerful idea of append only logs.