[jira] [Created] (DRILL-6857) Limit is not being pushed into scan when selecting from a parquet file with multiple row groups.

["Anton Gozhiy (JIRA)" <ji...@apache.org>]

Anton Gozhiy created DRILL-6857:
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             Summary: Limit is not being pushed into scan when selecting from a parquet file with multiple row groups.
                 Key: DRILL-6857
                 URL: https://issues.apache.org/jira/browse/DRILL-6857
             Project: Apache Drill
          Issue Type: Bug
    Affects Versions: 1.15.0
            Reporter: Anton Gozhiy
         Attachments: DRILL_5796_test_data.parquet

*Data:*
A parquet file that contains more than one row group. Example is attached.

*Query:*
{code:sql}
explain plan for select * from dfs.tmp.`DRILL_5796_test_data.parquet` limit 1
{code}

*Expected result:*
numFiles=1, numRowGroups=1

*Actual result:*
numFiles=1, numRowGroups=3
{noformat}
00-00    Screen : rowType = RecordType(DYNAMIC_STAR **): rowcount = 1.0, cumulative cost = {274.1 rows, 280.1 cpu, 270.0 io, 0.0 network, 0.0 memory}, id = 13671
00-01      Project(**=[$0]) : rowType = RecordType(DYNAMIC_STAR **): rowcount = 1.0, cumulative cost = {274.0 rows, 280.0 cpu, 270.0 io, 0.0 network, 0.0 memory}, id = 13670
00-02        SelectionVectorRemover : rowType = RecordType(DYNAMIC_STAR **): rowcount = 1.0, cumulative cost = {273.0 rows, 279.0 cpu, 270.0 io, 0.0 network, 0.0 memory}, id = 13669
00-03          Limit(fetch=[1]) : rowType = RecordType(DYNAMIC_STAR **): rowcount = 1.0, cumulative cost = {272.0 rows, 278.0 cpu, 270.0 io, 0.0 network, 0.0 memory}, id = 13668
00-04            Limit(fetch=[1]) : rowType = RecordType(DYNAMIC_STAR **): rowcount = 1.0, cumulative cost = {271.0 rows, 274.0 cpu, 270.0 io, 0.0 network, 0.0 memory}, id = 13667
00-05              Scan(table=[[dfs, tmp, DRILL_5796_test_data.parquet]], groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=maprfs:///tmp/DRILL_5796_test_data.parquet]], selectionRoot=maprfs:/tmp/DRILL_5796_test_data.parquet, numFiles=1, numRowGroups=3, usedMetadataFile=false, columns=[`**`]]]) : rowType = RecordType(DYNAMIC_STAR **): rowcount = 270.0, cumulative cost = {270.0 rows, 270.0 cpu, 270.0 io, 0.0 network, 0.0 memory}, id = 13666
{noformat}

*Note:*
The limit pushdown works with the same data partitioned by files (1 row group for a file )



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