fix: guard against Parquet getNumNulls returning -1 for missing null count - #17559
Open
waterWang wants to merge 1 commit into
Open
fix: guard against Parquet getNumNulls returning -1 for missing null count#17559waterWang wants to merge 1 commit into
waterWang wants to merge 1 commit into
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Fixes #17558
Parquet's Statistics#getNumNulls returns -1 when null_count is missing from the column chunk statistics. The current code unconditionally adds -1 to the accumulated null count, which produces incorrect results when multiple row groups are merged across a column chunk.
For example, with row group 0 having 1 null and row group 1 missing null_count (returning -1), the total becomes 0 instead of at least 1. A query engine relying on null count could skip the file entirely when evaluating predicates like WHERE c IS NULL, causing wrong results.
This fix wraps all getNumNulls() calls with Math.max(..., 0) to safely handle the missing null_count case across all four code paths: counts(), bounds(), and the two variant metric methods.