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Git's database internals I: packed object store

Blog post from GitHub

Post Details
Company
Date Published
Author
Derrick Stolee
Word Count
4,243
Language
English
Hacker News Points
-
Summary

The blog post delves into the intricacies of Git's internal architecture, emphasizing its role as a distributed database for source code management. It highlights Git's object store, which uses a content-addressable data model, allowing developers to retrieve data by its hash, akin to querying a database table with primary keys. The post explains how Git's use of packfiles and pack-indexes optimizes storage by compressing data and providing efficient access through binary search, despite lacking live updates typical of B-trees in databases. It discusses Git's reliance on short-lived processes and filesystem caching, contrasting it with long-running database processes that manage their own memory. The author suggests potential improvements for Git, such as incorporating database-like features for more efficient data retrieval, and previews upcoming discussions on Git commit history and the commit-graph file's role in optimizing queries.