Ala Luszczak created PARQUET-2161:
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Summary: Row positions are computed incorrectly when range or
offset metadata filter is used
Key: PARQUET-2161
URL: https://issues.apache.org/jira/browse/PARQUET-2161
Project: Parquet
Issue Type: Bug
Components: parquet-mr
Affects Versions: 1.12.3
Reporter: Ala Luszczak
The row indexes introduced in PARQUET-2117 are not computed correctly when
(1) range or offset metadata filter is applied, and
(2) the first row group was eliminated by the filter
For example, if a file has two row groups with 10 rows each, and we attempt to
only read the 2nd row group, we are going to produce row indexes 0, 1, 2, ...,
9 instead of expected 10, 11, ..., 19.
This happens because functions `filterFileMetaDataByStart` (used here:
https://github.com/apache/parquet-mr/blob/e06384455567c56d5906fc3a152ab00fd8dfdf33/parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java#L1453)
and `filterFileMetaDataByMidpoint` (used here:
https://github.com/apache/parquet-mr/blob/e06384455567c56d5906fc3a152ab00fd8dfdf33/parquet-hadoop/src/main/java/org/apache/parquet/format/converter/ParquetMetadataConverter.java#L1460)
modify their input `FileMetaData`. To address the issue we need to
`generateRowGroupOffsets` before these filters are applied.
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