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0.22.1: a table's extent and count from its manifests, not a scan of every file - #171
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…scan of every file `Table.open` learned its extent with `min/max/count(*)` over `iceberg_scan`, which reads every data file's footer: a request per file, on every open, of every reader. A log that publishes every few minutes grows thousands of small files, and one open took 20+ s from a laptop and minutes on a loaded box. The three numbers are in the manifests' per-file statistics (record counts and the offset column's bounds), one read of the manifest list and one per manifest. Falls back to the scan when the statistics cannot answer exactly: a file without bounds on the offset column, or a delete file. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01PXyESUWnfYF3jXPHp7pz12
A fix on the 0.22 line: Table.open reads a table's extent and count from its manifests instead of scanning every data file. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01PXyESUWnfYF3jXPHp7pz12
This was referenced Oct 20, 2026
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Hotfix on the 0.22 line (readers pinned <0.23).
Table.openranmin/max/count(*)overiceberg_scan, reading every data file's footer on every snapshot open; on a log with ~550 small files one open took 20+ s, minutes on a loaded box. The three numbers now come from the manifests' per-file statistics (one read of the manifest list plus one per manifest), falling back to the scan when a file lacks bounds or a delete file exists.New test: the manifest numbers equal the scan's, and
opennever issues the extent scan (fails when the fallback is forced). tests/test_published, snapshot_readers, restore, retention, catchup_pages: 58 passed. The same fix for main is onfix/table-open-extent-from-manifests.🤖 Generated with Claude Code
https://claude.ai/code/session_01PXyESUWnfYF3jXPHp7pz12