fix(parquet/pqarrow): Fix null_count column stats - #489
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zeroshade merged 1 commit intoSep 4, 2025
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I've added a new issue for the encoding panic I mentioned here |
zeroshade
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Sep 4, 2025
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Rationale for this change
When dictionary encoding is enabled and and repetitions are set to
required, thenull_countstatistic is negative becausedefLevelsis always 0.What changes are included in this PR?
This PR sets the null count to 0 if
defLevels - nonNullCount < 0Are these changes tested?
Yes. I've added a new test that exposes another bug. I started with the
fullTypeListvariable like this test and discovered that not all types are supported.If an unsupported type is encoded as a dictionary, it results in a nasty panic in the typed dictionary encoder because the types don't line up.
Are there any user-facing changes?
Yes, the stats written to parquet files are currently wrong for these sorts of columns. This PR should fix that!