Published onSeptember 29, 2026Birth of Parquet: Shrinking a Day of Ethereum Logs by 5xparquetdata-engineeringblockchainbig-dataoptimizationA short history of Parquet, then two experiments on one day of Ethereum logs: how bloom filters speed up lookups on a high-cardinality column, and how sorting and compression shrink a 1.2 GB file to 218 MB.