feat: preserve Arrow Date(MILLISECOND) columns through Spark roundtrip#464
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summaryzb wants to merge 1 commit intolance-format:mainfrom
Open
feat: preserve Arrow Date(MILLISECOND) columns through Spark roundtrip#464summaryzb wants to merge 1 commit intolance-format:mainfrom
summaryzb wants to merge 1 commit intolance-format:mainfrom
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Change-Id: I832408fa941c1ebdf59a61307bfcda4e183ba64f
hamersaw
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Apr 27, 2026
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hamersaw
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hamersaw
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Looks great! Lets just turn the TODO's into github issues and fix the integration tests then it will be ready to merge!
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| // TODO: Date(MILLISECOND), FixedSizeList, and LargeUtf8 metadata is lost for array | ||
| // elements because fromArrowField returns DataType without metadata. Track as a | ||
| // known limitation; address in a follow-up. |
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Can you make sure there is a ticket for this?
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And when it exists, lets remove the TODO comments. The captured ticket should be enough to remind us this needs to be fixed.
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Preserve Arrow
Date(MILLISECOND)columns through Spark read-write roundtrips by carrying the original Arrow date unit in Spark field metadata. Without this change, Lance datasets created by PyArrow or other non-Spark sources that useDate(MILLISECOND)would silently downgrade toDate(DAY)when written back through Spark, corrupting interoperability with downstream consumers that expect millisecond-unit dates.