Where can I find the implementation details of MongoDB B tree indexes?

[Ibolya_83267 (Ibolya Varga)]

Where can I find the implementation details of MongoDB B tree indexes?

[tapiocaPENGUIN (Eli Brunsvold)]

First, I’m assuming you mean how MongoDB uses B-Trees for their indexes because there is no “B-Tree” index I just wanted to clarify.

But I don’t think there is any documentation on how it is implemented, but there are some older posts that talk about it and link some pages that might be helpful to start to understand. It seems like if you understand the core concepts of B-Trees then you can get an idea of how they are used for indexes.

Why do indexes use B-Tree and not Binary Search Tree?

https://university.mongodb.com/mercury/M201/2020_July_7/chapter/Chapter_2_MongoDB_Indexes/lesson/58ab5626d280e426708ee3da/lecture In this Chapter it is mentioned Mongodb Uses B-Tree for Indexes. So i have a question Why it does not use Binary Search Tree because Insertion, deletion, searching of an element is faster in BINARY SEARCH TREE than BINARY TREE due to the ordered characteristics. So Does it Uses BST if no than Why?

[Christopher_Harris (Chris Harris)]

Hi @Ibolya_83267 - thanks for the question! Is there some specific problem that you are trying to solve by learning about the implementation details? Knowing more about what you are looking for may help us provide more relevant information to assist you.

Best,
Chris

[Ibolya_83267 (Ibolya Varga)]

I would like to use MongoDB index in implementing relational mini DBMS as exersice for my students. The hardest part of the project is to implement B-tree index, so I try to modify the specification and store the data file and the indexes in key-value files, using the index for key of a key-value file.
I have also a MongoDB course and try to explain the implementation details also, as RAFT algorithm and index implementation.
Thank you
Ibolya