Smart Compaction: Predicting Compaction Utility from Lakehouse Table Metadata
Quick summary
arXiv:2608.08639v1 Announce Type: new Abstract: Open lakehouse table formats accumulate small data files over time, which degrades query performance. Deciding when compaction is worthwhile remains threshold-driven, but which metadata features actually determine compaction utility is not well understood. We present an open simulation framework that generates 2,376 Apache Iceberg tables spanning three orders of magnitude in file size, extracts 17 metadata features from manifest files without reading data, and trains XGBoost to predict the continuous file-reduction ratio (R2 = 0.998, RMSE= 0.013)
Key takeaways
- arXiv:2608.08639v1 Announce Type: new Abstract: Open lakehouse table formats accumulate small data files over time, which degrades query performance.
- Deciding when compaction is worthwhile remains threshold-driven, but which metadata features actually determine compaction utility is not well understood.
- We present an open simulation framework that generates 2,376 Apache Iceberg tables spanning three orders of magnitude in file size, extracts 17 metadata features from manifest files without reading data, and trains XGBoost to predict the continuous file-reduction ratio (R2 = 0.998, RMSE= 0.013)
Why it matters
The importance of “Smart Compaction: Predicting Compaction Utility from Lakehouse Table Metadata” will be measured by what changes in practice. User behavior, access conditions, verifiable performance and responsible-use outcomes are the signals worth following.

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