v0.7.0

Codec-agnostic per-file statistics and nil metadata coalescing

Summary

v0.7.0 adds per-file column statistics to manifests (enabling pruning workflows without opening data files) and relaxes nil metadata handling across all write paths to coalesce to empty instead of returning an error.

Highlights

• Per-file column statistics: New StatisticalCodec and StatisticalStreamEncoder interfaces allow any codec to report per-file column stats (min, max, null count, distinct count) persisted on FileRef
• Parquet statistics: The Parquet codec implements StatisticalCodec, reporting column-level min/max/null count for all orderable types (int32, int64, float32, float64, string, timestamp)
• New public types: FileStats, ColumnStats on the public API surface
• Nil metadata coalescing: Write, StreamWrite, StreamWriteRecords, and Volume.Commit now coalesce nil metadata to Metadata{} instead of returning an error
• Contract updates: CONTRACT_CORE, CONTRACT_WRITE_API, CONTRACT_VOLUME, and CONTRACT_PARQUET updated to reflect new semantics
• 14 new stats tests and 4 updated coalescing tests with full traceability matrix coverage

Upgrade Notes

• Callers that previously passed Metadata{} solely to avoid nil errors can now pass nil safely
• Callers that relied on nil metadata returning an error should remove that expectation
• Per-file stats are opt-in: only codecs implementing StatisticalCodec produce them; manifests without stats remain valid

References

• Per-file statistics: #103
• Nil metadata coalescing + housekeeping: #104

Full Changelog: v0.6.0...v0.7.0

What's Changed

• docs(agents): 📝 enhance AGENTS.md with Go style and composition guardrails by @justapithecus in #102
• feat(manifest): ✨ add per-file column statistics for codec-agnostic pruning by @justapithecus in #103
• chore(api): 🩹 post-stats housekeeping and nil metadata coalescing by @justapithecus in #104
• docs: 📝 backfill CHANGELOG for v0.6.0 and v0.7.0 by @justapithecus in #105

Full Changelog: v0.6.0...v0.7.0