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https://issues.apache.org/jira/browse/PARQUET-2161?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17558001#comment-17558001
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ASF GitHub Bot commented on PARQUET-2161:
-----------------------------------------
ala commented on PR #978:
URL: https://github.com/apache/parquet-mr/pull/978#issuecomment-1164263841
cc @shangxinli This is a small follow-up bug fix for
https://github.com/apache/parquet-mr/pull/945
> 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
> Priority: Major
>
> 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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