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https://issues.apache.org/jira/browse/HIVE-22239?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Jesus Camacho Rodriguez updated HIVE-22239:
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Description: 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.
(was: 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.
This patch also includes the propagation of min/max column values from
statistics to the optimizer for timestamp type.)
> 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: 3h 50m
> 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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