[
https://issues.apache.org/jira/browse/HIVE-22893?focusedWorklogId=393065&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-393065
]
ASF GitHub Bot logged work on HIVE-22893:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 26/Feb/20 00:09
Start Date: 26/Feb/20 00:09
Worklog Time Spent: 10m
Work Description: jcamachor commented on pull request #915: HIVE-22893
StatEstimate
URL: https://github.com/apache/hive/pull/915#discussion_r384200546
##########
File path: ql/src/java/org/apache/hadoop/hive/ql/stats/StatsUtils.java
##########
@@ -1560,6 +1554,32 @@ public static ColStatistics
getColStatisticsFromExpression(HiveConf conf, Statis
}
}
+ if (conf.getBoolVar(ConfVars.HIVE_STATS_USE_UDF_ESTIMATORS)) {
+ Optional<IStatEstimatorProvider> sep =
engfd.getGenericUDF().adapt(IStatEstimatorProvider.class);
+ if (sep.isPresent()) {
+ Optional<IStatEstimator> se = sep.get().getStatEstimator();
Review comment:
Should we assume that if a UDF is an estimator provider, it should provide
an estimator, and thus, throw an exception here if we cannot get the estimator?
----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
For queries about this service, please contact Infrastructure at:
us...@infra.apache.org
Issue Time Tracking
-------------------
Worklog Id: (was: 393065)
Time Spent: 20m (was: 10m)
> Enhance data size estimation for fields computed by UDFs
> --------------------------------------------------------
>
> Key: HIVE-22893
> URL: https://issues.apache.org/jira/browse/HIVE-22893
> Project: Hive
> Issue Type: Improvement
> Components: Statistics
> Reporter: Zoltan Haindrich
> Assignee: Zoltan Haindrich
> Priority: Major
> Labels: pull-request-available
> Attachments: HIVE-22893.01.patch, HIVE-22893.02.patch,
> HIVE-22893.03.patch, HIVE-22893.04.patch, HIVE-22893.05.patch,
> HIVE-22893.06.patch, HIVE-22893.07.patch, HIVE-22893.08.patch,
> HIVE-22893.09.patch, HIVE-22893.10.patch, HIVE-22893.11.patch,
> HIVE-22893.12.patch
>
> Time Spent: 20m
> Remaining Estimate: 0h
>
> Right now if we have columnstat on a column ; we use that to estimate things
> about the column; - however if an UDF is executed on a column ; the resulting
> column is treated as unknown thing and defaults are assumed.
> An improvement could be to give wide estimation(s) in case of frequently used
> udf.
> For example; consider {{substr(c,1,1)}} ; no matter what the input; the
> output is at most a 1 long string
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
