---
title: "B-Tree vs. LSM-Tree"
description: "Explore the differences between B-Tree and LSM-Tree data structures."
image: "https://assets.bytebytego.com/diagrams/0091-btree-lsm.png"
createdAt: "2024-02-16"
draft: false
categories:
  - database-and-storage
tags:
  - "Data Structures"
  - "Databases"
---

![a close up of a chart](https://assets.bytebytego.com/diagrams/0091-btree-lsm.png)

## B-Tree

B-Tree is the most widely used indexing data structure in almost all relational databases.

The basic unit of information storage in B-Tree is usually called a “page”. Looking up a key traces down the range of keys until the actual value is found.

## LSM-Tree

LSM-Tree (Log-Structured Merge Tree) is widely used by many NoSQL databases, such as Cassandra, LevelDB, and RocksDB.

LSM-trees maintain key-value pairs and are persisted to disk using a Sorted Strings Table (SSTable), in which the keys are sorted.

Level 0 segments are periodically merged into Level 1 segments. This process is called **compaction.**

The biggest difference is probably this:

*   B-Tree enables faster reads

*   LSM-Tree enables fast writes