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https://issues.apache.org/jira/browse/DRILL-5795?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16206794#comment-16206794
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ASF GitHub Bot commented on DRILL-5795:
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Github user priteshm commented on the issue:
https://github.com/apache/drill/pull/949
@paul-rogers, @kkhatua can you provide some more information on the test
case that failed? Hopefully, @dprofeta can replicate it in his environment.
> Filter pushdown for parquet handles multi rowgroup file
> -------------------------------------------------------
>
> Key: DRILL-5795
> URL: https://issues.apache.org/jira/browse/DRILL-5795
> Project: Apache Drill
> Issue Type: Improvement
> Components: Storage - Parquet
> Affects Versions: 1.11.0
> Reporter: Damien Profeta
> Assignee: Damien Profeta
> Labels: doc-impacting, ready-to-commit
> Fix For: 1.12.0
>
> Attachments: multirowgroup_overlap.parquet
>
>
> DRILL-1950 implemented the filter pushdown for parquet file but only in the
> case of one rowgroup per parquet file. In the case of multiple rowgroups per
> files, it detects that the rowgroup can be pruned but then tell to the
> drillbit to read the whole file which leads to performance issue.
> Having multiple rowgroup per file helps to handle partitioned dataset and
> still read only the relevant subset of data without ending with more file
> than really needed.
> Let's say for instance you have a Parquet file composed of RG1 and RG2 with
> only one column a. Min/max in RG1 are 1-2 and min/max in RG2 are 2-3.
> If I do "select a from file where a=3", today it will read the whole file,
> with the patch it will only read RG2.
> *For documentation*
> Support / Other section in
> https://drill.apache.org/docs/parquet-filter-pushdown/ should be updated.
> After the fix files with multiple row groups will be supported.
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