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https://issues.apache.org/jira/browse/HIVE-15240?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Rajesh Balamohan updated HIVE-15240:
------------------------------------
Attachment: HIVE-15240.1.patch
As part of "StatsTask -> updateQuickStats" itself, statistics like number of
files & total size are updated in the partition parameters. So no need to
update these fast-stats in "StatsTask -> aggregateStats -> db.alterPartitions".
{noformat}
drop web_returns table and populate it back with the data.
..
..
insert into table web_returns partition(wr_returned_date_sk) select * from
tpcds_bin_partitioned_200.web_returns
{noformat}
Total number of partitions were around 2184 and entire dataset was in S3.
||Run ID||Without Patch (secs)||With Patch (secs)||
|Run 1|1025.526|688.752|
|Run 2|1031.841|665.139|
|Run 3|1017.168|669.171|
*~35%* reduction in response time is observed with the patch.
> Updating/Altering stats in metastore can be expensive in S3
> -----------------------------------------------------------
>
> Key: HIVE-15240
> URL: https://issues.apache.org/jira/browse/HIVE-15240
> Project: Hive
> Issue Type: Improvement
> Components: Metastore
> Reporter: Rajesh Balamohan
> Priority: Minor
> Attachments: HIVE-15240.1.patch
>
>
> https://github.com/apache/hive/blob/master/metastore/src/java/org/apache/hadoop/hive/metastore/HiveAlterHandler.java#L630
> https://github.com/apache/hive/blob/master/metastore/src/java/org/apache/hadoop/hive/metastore/MetaStoreUtils.java#L367
> If there are 100 partitions, it iterates every partition to determine its
> location taking up more than good amount of time.
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