docs: correct alter_columns nullable docstring#7095
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The alter_columns docstring claimed a nullable column cannot be made non-nullable. That restriction was lifted in lance-format#5589; a nullable column can now be made non-nullable as long as it contains no NULL values. Update the docstring to describe the actual behavior in both directions. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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Thanks for the update! Just checked this in the Rust core, it makes sense and LGTM.
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Summary
The
LanceDataset.alter_columnsdocstring states that a nullable column cannot be made non-nullable:This is out of date. Support for changing a nullable column to non-nullable was added in #5589 (
validate_no_nulls_before_making_non_nullableinrust/lance/src/dataset/schema_evolution.rs), and the Python binding already plumbsnullablethrough (python/src/dataset.rs). The only requirement is that the column contains no NULL values, otherwise an error is raised.This PR updates the docstring to describe the actual behavior in both directions.
Changes
"nullable"parameter docs foralter_columnsto reflect that a nullable column can be made non-nullable when it has no NULL values.Notes
Docs-only change; no functional change and no test impact. Lint was deferred to CI for this docstring-only edit.
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