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https://issues.apache.org/jira/browse/HIVE-16600?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16000206#comment-16000206
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liyunzhang_intel edited comment on HIVE-16600 at 5/8/17 3:26 AM:
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[~lirui], [~xuefuz]: I update HIVE-16600.1.patch. help review
{noformat}
in the case i provided in description, after HIVE-16600.1.patch, the
parallelism of RS[2] (Sort)is 46. without HIVE-16600.1.patch, the parallelism
of RS[2](Sort) is 1.
before HIVE-16600.1.patch
the parallelism of RS[2] is 1
#grep SetSparkReducerParallelism logs/hive.log
2017-05-08T10:31:10,820 INFO [63ddd225-f012-4b14-9141-38597f94c85b main]
spark.SetSparkReducerParallelism: Number of reducers determined to be: 1
after HIVE-16600.1.patch
the parallelism of RS[2] is 46
#grep SetSparkReducerParallelism logs/hive.log
2017-05-08T10:22:49,432 DEBUG [42c701ac-380e-43e3-a3ab-f5aa7c2b55ee main]
spark.SetSparkReducerParallelism: Sibling RS[2] has stats: Num rows: 29 Data
size: 5812 Basic stats: COMPLETE Column stats: NONE
2017-05-08T10:23:10,403 INFO [42c701ac-380e-43e3-a3ab-f5aa7c2b55ee main]
spark.SetSparkReducerParallelism: Set parallelism for reduce sink RS[2] to: 46
(calculated)
{noformat}
was (Author: kellyzly):
[~lirui]: I update HIVE-16600.1.patch. help review
{noformat}
in the case i provided in description, after HIVE-16600.1.patch, the
parallelism of RS[2] (Sort)is 46. without HIVE-16600.1.patch, the parallelism
of RS[2](Sort) is 1.
before HIVE-16600.1.patch
the parallelism of RS[2] is 1
#grep SetSparkReducerParallelism logs/hive.log
2017-05-08T10:31:10,820 INFO [63ddd225-f012-4b14-9141-38597f94c85b main]
spark.SetSparkReducerParallelism: Number of reducers determined to be: 1
after HIVE-16600.1.patch
the parallelism of RS[2] is 46
#grep SetSparkReducerParallelism logs/hive.log
2017-05-08T10:22:49,432 DEBUG [42c701ac-380e-43e3-a3ab-f5aa7c2b55ee main]
spark.SetSparkReducerParallelism: Sibling RS[2] has stats: Num rows: 29 Data
size: 5812 Basic stats: COMPLETE Column stats: NONE
2017-05-08T10:23:10,403 INFO [42c701ac-380e-43e3-a3ab-f5aa7c2b55ee main]
spark.SetSparkReducerParallelism: Set parallelism for reduce sink RS[2] to: 46
(calculated)
{noformat}
> Refactor SetSparkReducerParallelism#needSetParallelism to enable parallel
> order by in multi_insert cases
> --------------------------------------------------------------------------------------------------------
>
> Key: HIVE-16600
> URL: https://issues.apache.org/jira/browse/HIVE-16600
> Project: Hive
> Issue Type: Sub-task
> Reporter: liyunzhang_intel
> Assignee: liyunzhang_intel
> Attachments: HIVE-16600.1.patch
>
>
> multi_insert_gby.case.q
> {code}
> set hive.exec.reducers.bytes.per.reducer=256;
> set hive.optimize.sampling.orderby=true;
> drop table if exists e1;
> drop table if exists e2;
> create table e1 (key string, value string);
> create table e2 (key string);
> FROM (select key, cast(key as double) as keyD, value from src order by key) a
> INSERT OVERWRITE TABLE e1
> SELECT key, value
> INSERT OVERWRITE TABLE e2
> SELECT key;
> select * from e1;
> select * from e2;
> {code}
> the parallelism of Sort is 1 even we enable parallel order
> by("hive.optimize.sampling.orderby" is set as "true"). This is not
> reasonable because the parallelism should be calcuated by
> [Utilities.estimateReducers|https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/optimizer/spark/SetSparkReducerParallelism.java#L170]
> this is because SetSparkReducerParallelism#needSetParallelism returns false
> when [children size of
> RS|https://github.com/apache/hive/blob/master/ql/src/java/org/apache/hadoop/hive/ql/optimizer/spark/SetSparkReducerParallelism.java#L207]
> is greater than 1.
> in this case, the children size of {{RS[2]}} is two.
> the logical plan of the case
> {code}
> TS[0]-SEL[1]-RS[2]-SEL[3]-SEL[4]-FS[5]
> -SEL[6]-FS[7]
> {code}
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