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https://issues.apache.org/jira/browse/DRILL-4905?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15586883#comment-15586883
]
ASF GitHub Bot commented on DRILL-4905:
---------------------------------------
Github user ppadma commented on a diff in the pull request:
https://github.com/apache/drill/pull/597#discussion_r83965044
--- Diff:
exec/java-exec/src/test/java/org/apache/drill/exec/store/parquet/TestParquetGroupScan.java
---
@@ -117,4 +119,18 @@ public void testSelectEmptyNoCache() throws Exception {
uex.getMessage()), uex.getMessage().contains(expectedMsg));
}
}
+
+ @Test
+ public void testLimit() throws Exception {
+ List<QueryDataBatch> results =
testSqlWithResults(String.format("select * from cp.`parquet/limitTest.parquet`
limit 1"));
--- End diff --
done
> Push down the LIMIT to the parquet reader scan to limit the numbers of
> records read
> -----------------------------------------------------------------------------------
>
> Key: DRILL-4905
> URL: https://issues.apache.org/jira/browse/DRILL-4905
> Project: Apache Drill
> Issue Type: Bug
> Components: Storage - Parquet
> Affects Versions: 1.8.0
> Reporter: Padma Penumarthy
> Assignee: Padma Penumarthy
> Fix For: 1.9.0
>
>
> Limit the number of records read from disk by pushing down the limit to
> parquet reader.
> For queries like
> select * from <table> limit N;
> where N < size of Parquet row group, we are reading 32K/64k rows or entire
> row group. This needs to be optimized to read only N rows.
>
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