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https://issues.apache.org/jira/browse/HIVE-24367?focusedWorklogId=707425&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-707425
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ASF GitHub Bot logged work on HIVE-24367:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 12/Jan/22 12:02
Start Date: 12/Jan/22 12:02
Worklog Time Spent: 10m
Work Description: HarshitGupta11 commented on a change in pull request
#2771:
URL: https://github.com/apache/hive/pull/2771#discussion_r783011556
##########
File path: ql/src/java/org/apache/hadoop/hive/ql/stats/BasicStatsTask.java
##########
@@ -136,6 +136,11 @@ public BasicStatsProcessor(Partish partish, BasicStatsWork
work, HiveConf conf,
}
}
+ public boolean canTrim(){
Review comment:
The stats update will work only for tables that are non-partitioned and
in the queries where there is a single stats stage(otherwise it will lead to
overcounting) and some other conditions. So here it checks for those conditions.
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Issue Time Tracking
-------------------
Worklog Id: (was: 707425)
Time Spent: 1h (was: 50m)
> Explore whether HiveAlterHandler::alterTable can be optimised for
> non-partitioned tables
> ----------------------------------------------------------------------------------------
>
> Key: HIVE-24367
> URL: https://issues.apache.org/jira/browse/HIVE-24367
> Project: Hive
> Issue Type: Improvement
> Components: HiveServer2
> Reporter: Rajesh Balamohan
> Assignee: Harshit Gupta
> Priority: Major
> Labels: pull-request-available
> Time Spent: 1h
> Remaining Estimate: 0h
>
> {color:#222222}Writing lots of delta in non-partitioned table creates runtime
> issues, when lot of delta folders are present.{color}
> {color:#222222} {color}
> {color:#222222}Following code in HiveAlterHandler is invoked for every insert
> operation. It computes {{{color}
> {color:#222222}updateTableStatsSlow}} for every insert causing runtime
> delays.{color}
> {color:#222222} {color}
> {noformat}
> if (MetaStoreUtils.requireCalStats(null, null, newt, environmentContext) &&
> !isPartitionedTable) {
> Database db = msdb.getDatabase(catName, newDbName);
> assert(isReplicated == HiveMetaStore.HMSHandler.isDbReplicationTarget(db));
> // Update table stats. For partitioned table, we update stats in
> alterPartition()
> MetaStoreUtils.updateTableStatsSlow(db, newt, wh, false, true,
> environmentContext);
> }
> {noformat}
> {color:#222222}It would be good to explore whether only the newly added delta
> can be listed for computing stats. This would avoid huge listing call during
> stats collection.{color}
> {color:#222222}e.g queries to repro{color}
> {noformat}
> CREATE TABLE IF NOT EXISTS test (name String, value int);
> INSERT INTO test VALUES('K1',1);
> INSERT INTO test VALUES('K2',2);
> ..
> ..
> ..
> INSERT INTO test VALUES('K20000',2)
> {noformat}
>
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