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https://issues.apache.org/jira/browse/HIVE-23006?focusedWorklogId=402532&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-402532
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ASF GitHub Bot logged work on HIVE-23006:
-----------------------------------------
Author: ASF GitHub Bot
Created on: 12/Mar/20 22:52
Start Date: 12/Mar/20 22:52
Worklog Time Spent: 10m
Work Description: pgaref commented on pull request #952: HIVE-23006
ProbeDecode compiler support
URL: https://github.com/apache/hive/pull/952
This patch adds an extra optimisation step with the goal of finding Table
Scan operators that could reduce the number of rows decoded at runtime using
extra available information.
It currently looks for all the available MapJoin operators that could use
the smaller HashTable on the probing side (where TS is) to filter-out rows that
would never match.
To do so the HashTable information is pushed down to the TS properties and
then propagated as part of MapWork.
If the a single TS is used by multiple operators (shared-word), this rule
can not be applied.
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Issue Time Tracking
-------------------
Worklog Id: (was: 402532)
Remaining Estimate: 0h
Time Spent: 10m
> Compiler support for Probe MapJoin
> ----------------------------------
>
> Key: HIVE-23006
> URL: https://issues.apache.org/jira/browse/HIVE-23006
> Project: Hive
> Issue Type: Sub-task
> Reporter: Panagiotis Garefalakis
> Assignee: Panagiotis Garefalakis
> Priority: Major
> Labels: pull-request-available
> Time Spent: 10m
> Remaining Estimate: 0h
>
> The decision of pushing down information to the Record reader (potentially
> reducing decoding time by row-level filtering) should be done at query
> compilation time.
> This patch adds an extra optimisation step with the goal of finding Table
> Scan operators that could reduce the number of rows decoded at runtime using
> extra available information.
> It currently looks for all the available MapJoin operators that could use the
> smaller HashTable on the probing side (where TS is) to filter-out rows that
> would never match.
> To do so the HashTable information is pushed down to the TS properties and
> then propagated as part of MapWork.
> If the a single TS is used by multiple operators (shared-word), this rule can
> not be applied.
> This rule can be extended to support static filter expressions like:
> _select * from sales where sold_state = 'PR';_
> This optimisation manly targets the Tez execution engine running on Llap.
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