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https://issues.apache.org/jira/browse/HIVE-22239?focusedWorklogId=325750&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-325750
]
ASF GitHub Bot logged work on HIVE-22239:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 09/Oct/19 15:08
Start Date: 09/Oct/19 15:08
Worklog Time Spent: 10m
Work Description: jcamachor commented on pull request #787: HIVE-22239
URL: https://github.com/apache/hive/pull/787#discussion_r333070056
##########
File path:
ql/src/java/org/apache/hadoop/hive/ql/optimizer/stats/annotation/StatsRulesProcFactory.java
##########
@@ -967,13 +979,23 @@ private long evaluateComparator(Statistics stats,
AnnotateStatsProcCtx aspCtx, E
if (minValue > value) {
return 0;
}
+ if (uniformWithinRange) {
+ // Assuming uniform distribution, we can use the range to
calculate
+ // new estimate for the number of rows
+ return Math.round(((double) (value - minValue) / (maxValue -
minValue)) * numRows);
Review comment:
Good catch. I fixed that in latest patch.
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Issue Time Tracking
-------------------
Worklog Id: (was: 325750)
Time Spent: 4h 20m (was: 4h 10m)
> Scale data size using column value ranges
> -----------------------------------------
>
> Key: HIVE-22239
> URL: https://issues.apache.org/jira/browse/HIVE-22239
> Project: Hive
> Issue Type: Improvement
> Components: Physical Optimizer
> Reporter: Jesus Camacho Rodriguez
> Assignee: Jesus Camacho Rodriguez
> Priority: Major
> Labels: pull-request-available
> Attachments: HIVE-22239.01.patch, HIVE-22239.02.patch,
> HIVE-22239.patch
>
> Time Spent: 4h 20m
> Remaining Estimate: 0h
>
> Currently, min/max values for columns are only used to determine whether a
> certain range filter falls out of range and thus filters all rows or none at
> all. If it does not, we just use a heuristic that the condition will filter
> 1/3 of the input rows. Instead of using that heuristic, we can use another
> one that assumes that data will be uniformly distributed across that range,
> and calculate the selectivity for the condition accordingly.
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