# What is LSM?
+ **`B+-Tree`**
  + **_`in-place`_** update
  + Optimized for read
+ **`LSM (Log-Structured Merge-tree)`**
  + A data structure with performance characteristics that optimized for storing data with high insert and update rates
  + **_`out-of-place`_** update
  + Optimized for write
  + Requires data reorganization

![`smart`](BTreeLMSTree_aa_001_20221020.png)
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