使用Homebrew安装MongoDB时，SQLite为何是其依赖？

Great question—this had me scratching my head the first time I saw it too! At first glance, it seems totally odd: MongoDB’s a document-oriented database with its own storage engines (like WiredTiger), while SQLite’s a tiny relational, file-based DB. Why would they be linked?

Let’s clear up the confusion:

• MongoDB itself doesn’t need SQLite at all for its core database functionality. There’s no overlap in how they store or process data here—this isn’t a case of MongoDB using SQLite under the hood.
• The dependency is indirect, thanks to Homebrew’s package chain. If you peek at Homebrew’s MongoDB formula, you’ll notice it relies on python@3.12 for various behind-the-scenes tasks: think post-install setup scripts, helper utilities, or even some tooling bundled with the MongoDB package.
• Homebrew’s Python distribution depends on SQLite by default. Python’s standard library includes the sqlite3 module, which requires the underlying SQLite library to exist on your system. So when you install MongoDB, Homebrew pulls in Python first, which then triggers the installation of SQLite as a required dependency for Python.

Want to verify this yourself? Run this command in your terminal to see the full dependency tree:

brew deps --tree mongodb

You’ll see SQLite is nested under Python, not directly under MongoDB—proof it’s just a side effect of the package chain.

内容的提问来源于stack exchange，提问作者moth