LearnedSecondaryIndex

Overview

This repo is the main codebase for our paper LSI: A Learned Secondary Index Structure.

Learned Secondary Index (LSI) is a first attempt to use learned indexes for indexing unsorted data. LSI works by building a learned index over a permutation vector, which allows binary search to performed on the unsorted base data using random access. We additionally augment LSI with a fingerprint vector to accelerate equality lookups.

Usage

Execute ./test.sh to run our testcases and ./run.sh to run our benchmarks. Note that you may need to edit the .env file first to contain the correct path to your compiler. Any recent version of clang should work.

Run all cells in paper_plots.ipynb to recreate the plots in results/.

CMake

You can include lsi in your own CMake based project like this:

include(FetchContent)
FetchContent_Declare(
    lsi
    GIT_REPOSITORY "https://github.com/learnedsystems/LearnedSecondaryIndex"
    GIT_TAG main
)
FetchContent_MakeAvailable(lsi)

target_link_libraries(your_target lsi)

Structure

• include/ contains the code newly contributed by our work
• src/ contains tests, benchmark driver code and competitors
• results/ contains the results referenced in the paper and the accompanying plots

Cite

Please cite our aiDM@SIGMOD 2022 paper if you use this code in your own work, e.g.:

@misc{learnedsecondaryindex,
  doi = {10.48550/ARXIV.2205.05769},
  url = {https://arxiv.org/abs/2205.05769},
  author = {Kipf, Andreas and Horn, Dominik and Pfeil, Pascal and Marcus, Ryan and Kraska, Tim},
  keywords = {Databases (cs.DB), Machine Learning (cs.LG), FOS: Computer and information sciences, FOS: Computer and information sciences},
  title = {LSI: A Learned Secondary Index Structure},
  publisher = {arXiv},
  year = {2022}, 
  copyright = {arXiv.org perpetual, non-exclusive license}
}