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https://issues.apache.org/jira/browse/HIVE-29424?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Thomas Rebele updated HIVE-29424:
---------------------------------
Description:
Similar to HIVE-29364: the CBO planner should use the histogram statistics to
estimate the selectivity of predicates such as
* {{cast(b as BIGINT) < 6}}
* {{cast(g as timestamp) >= "2020-11-7 00:00:00"}}
* {{cast(g as timestamp) BETWEEN "2020-11-01 00:00:00" AND "2020-11-06
00:00:00"}}
The hint of HIVE-29364 should be taken into account: if the CAST throws away
information, the histogram statistics should not be used. E.g., {{{}CAST(128 as
TINYINT) = -128{}}}, so a {{CAST(intField as TINYINT) > 42}} should not be
treated the same as {{{}intField > 42{}}}, if the intField is outside of the
range of TINYINT.
This change would allow Hive to use the histogram statistics for many TPC-DS
queries, e.g., query 82 contains a {{{}d_date between cast('2002-05-30' as
date) and (cast('2002-05-30' as date) + 60 days){}}}, which will be implicitly
converted to a RexNode {{{}BETWEEN(false, CAST($2):TIMESTAMP(9), 2002-05-30
00:00:00:TIMESTAMP(9), 2002-07-29 00:00:00:TIMESTAMP(9)){}}}.
was:
Similar to HIVE-29364: the CBO planner should use the histogram statistics to
estimate the selectivity of predicates such as
* {{cast(b as BIGINT) < 6}}
* {{cast(g as timestamp) >= "2020-11-7 00:00:00"}}
* {{cast(g as timestamp) BETWEEN "2020-11-01 00:00:00" AND "2020-11-06
00:00:00"}}
The hint of HIVE-29364 should be taken into account: if the CAST throws away
information, the histogram statistics should not be used. E.g., {{{}CAST(128 as
TINYINT) = -128{}}}, so a {{CAST(intField as TINYINT) > 42}} should not be
treated the same as {{{}intField > 42{}}}, if the intField is outside of the
range of TINYINT.
> CBO plans should use histogram statistics for range predicates with a CAST
> --------------------------------------------------------------------------
>
> Key: HIVE-29424
> URL: https://issues.apache.org/jira/browse/HIVE-29424
> Project: Hive
> Issue Type: Improvement
> Reporter: Thomas Rebele
> Assignee: Thomas Rebele
> Priority: Major
> Labels: pull-request-available
>
> Similar to HIVE-29364: the CBO planner should use the histogram statistics to
> estimate the selectivity of predicates such as
> * {{cast(b as BIGINT) < 6}}
> * {{cast(g as timestamp) >= "2020-11-7 00:00:00"}}
> * {{cast(g as timestamp) BETWEEN "2020-11-01 00:00:00" AND "2020-11-06
> 00:00:00"}}
> The hint of HIVE-29364 should be taken into account: if the CAST throws away
> information, the histogram statistics should not be used. E.g., {{{}CAST(128
> as TINYINT) = -128{}}}, so a {{CAST(intField as TINYINT) > 42}} should not be
> treated the same as {{{}intField > 42{}}}, if the intField is outside of the
> range of TINYINT.
> This change would allow Hive to use the histogram statistics for many TPC-DS
> queries, e.g., query 82 contains a {{{}d_date between cast('2002-05-30' as
> date) and (cast('2002-05-30' as date) + 60 days){}}}, which will be
> implicitly converted to a RexNode {{{}BETWEEN(false, CAST($2):TIMESTAMP(9),
> 2002-05-30 00:00:00:TIMESTAMP(9), 2002-07-29 00:00:00:TIMESTAMP(9)){}}}.
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