Lightweight Correlation-Aware Table Compression

Mihail Stoian, Alexander van Renen, Jan Kobiolka, Ping-Lin Kuo, Josif Grabocka, Andreas Kipf

Keywords: table compression, correlation-aware compression, data lake, open storage format

TL;DR: Virtual enables correlation-aware compression with fast column scans; plug-in for any open storage format, such as Apache Parquet.

Abstract: The growing adoption of data lakes for managing relational data necessitates efficient, open storage formats that provide high scan performance and competitive compression ratios. While existing formats achieve fast scans through lightweight encoding techniques, they have reached a plateau in terms of minimizing storage footprint. Recently, correlation-aware compression schemes have been shown to reduce file sizes further. Yet, current approaches either incur significant scan overheads or require manual specification of correlations, limiting their practicability. We present Virtual, a framework that integrates seamlessly with existing open formats to automatically leverage data correlations, achieving substantial compression gains while having minimal scan performance overhead. Experiments on data.gov datasets show that Virtual reduces file sizes by up to 40% compared to Apache Parquet.

Submission Number: 14