I Compacted 1,000 Apache Iceberg Files Into 6. Here’s What Happened to Query Performance.
Data EngineeringI Compacted 1,000 Apache Iceberg Files Into 6. Here’s What Happened to Query Performance.Benchmarking the impact of fewer, larger files across three SQL workloadsThomas ReidSeptember 29, 202613 min readImage by AIWhen you deal with large analytical datasets stored in table formats such as Apache Iceberg, there is a known issue called the small files problem. This happens when data is written in lots of tiny files rather than a smaller number of reasonably sized ones.
- ▪Data EngineeringI Compacted 1,000 Apache Iceberg Files Into 6.
- ▪Here’s What Happened to Query Performance.Benchmarking the impact of fewer, larger files across three SQL workloadsThomas ReidSeptember 29, 202613 min readImage by AIWhen you deal with large analytical datasets stored in table formats such
- ▪This happens when data is written in lots of tiny files rather than a smaller number of reasonably sized ones.
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| Original publisher | Towards Data Science |
| Canonical URL | https://towardsdatascience.com/i-compacted-1000-apache-iceberg-files-into-6-heres-what-happened-to-query-performance/ |
| Publication time | Tue, 29 Sep 2026 15:30:01 GMT |
| Retrieval time | 2026-09-29T15:31:39.298Z |
| Last seen | 2026-09-29T15:31:39.298Z |
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Data EngineeringI Compacted 1,000 Apache Iceberg Files Into 6. Here’s What Happened to Query Performance.Benchmarking the impact of fewer, larger files across three SQL workloadsThomas ReidSeptember 29, 202613 min readImage by AIWhen you deal with large analytical datasets stored in table formats such as Apache Iceberg, there is a known issue called the small files problem. This happens when data is written in lots of tiny files rather than a smaller number of reasonably sized ones. This increases metadata overhead and can slow down query planning and execution.To combat this, a process called compaction is used which combines all the smaller files into a small number of larger files.
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Excerpt limited to ~120 words for fair-use compliance. The full article is at Towards Data Science.
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