> CONCLUSION

> We introduced BtrBlocks, an open columnar compression format for data lakes. By analyzing a collection of real-world datasets, we selected a pool of fast encoding schemes for this use case. Additionally, we introduced Pseudodecimal Encoding, a novel compression scheme for floating-point numbers. Using our sample-based compression scheme selection algorithm and our generic framework for cascading compression, we showed that, compared to existing data lake formats, BtrBlocks achieves a high compression factor, competitive compression speed and superior decompression performance. BtrBlocks is open source and available at https://github.com/maxi-k/btrblocks.