[
https://issues.apache.org/jira/browse/PARQUET-2161?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17556329#comment-17556329
]
ASF GitHub Bot commented on PARQUET-2161:
-----------------------------------------
ala opened a new pull request, #978:
URL: https://github.com/apache/parquet-mr/pull/978
Make sure you have checked _all_ steps below.
### Jira
- [x] My PR addresses the following [Parquet
Jira](https://issues.apache.org/jira/browse/PARQUET/) issues and references
them in the PR title. For example, "PARQUET-1234: My Parquet PR"
- https://issues.apache.org/jira/browse/PARQUET-2161
- In case you are adding a dependency, check if the license complies with
the [ASF 3rd Party License
Policy](https://www.apache.org/legal/resolved.html#category-x).
### Tests
- [x] My PR adds the following unit tests __OR__ does not need testing for
this extremely good reason:
- Extends `TestParquetReader` suite.
### Commits
- [x] My commits all reference Jira issues in their subject lines. In
addition, my commits follow the guidelines from "[How to write a good git
commit message](http://chris.beams.io/posts/git-commit/)":
1. Subject is separated from body by a blank line
1. Subject is limited to 50 characters (not including Jira issue reference)
1. Subject does not end with a period
1. Subject uses the imperative mood ("add", not "adding")
1. Body wraps at 72 characters
1. Body explains "what" and "why", not "how"
### Documentation
- [x] In case of new functionality, my PR adds documentation that describes
how to use it.
- All the public functions and the classes in the PR contain Javadoc that
explain what it does
> 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.
--
This message was sent by Atlassian Jira
(v8.20.7#820007)
