What is in a Lucene index? Adrien Grand, Software Engineer, Elasticsearch
Why Hacker News recommends it
HN recommends it as an instructive, easy-to-follow look at Lucene internals from a core committer.
What it is
Elasticsearch engineer and Lucene committer Adrien Grand explains the design decisions inside a Lucene index and what problems it can and cannot solve. The talk goes into how Lucene stores data for fast search and analytics.
Recommended by 3 HN commenters across 3 different months, 2019 to 2020.
What Hacker News said
Strong rec drej · 2020-01 · on “Elasticsearch from the Bottom Up (2013)”
I can super highly recommend talks by Adrien Grand on Lucene and Elasticsearch. They are super instructive yet easy to follow. [this video] [LINK]
Recommends ddorian43 · 2019-09 · on “Challenges in Implementing a Full-Text-Search Engine”
This is extremely high level. A nice view of how lucene internals work by core committer Adrien Grand: [LINK] [this video]
Recommends stereosteve · 2020-06 · on “Reducing search indexing latency to one second”
This is excellent. I was recently reviewing Lucene concepts and found this video really good: [this video] Also this site has a series of Lucene articles that are pretty nice. The one on Term Vectors in particular: [LINK] Based on some quick research it seems like Lucene is already using a sorted skip data structure for the posting list, so I wonder why they had to do a custom implementation? Perhaps it has to do with their custom Document ID scheme and how they want to preserve order in the Posting List being different from the default behavior. It also sounds like searchers are searching on indexes as they're being written, and there is some custom coordination around visibility, which might re