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https://issues.apache.org/jira/browse/TRAFODION-2263?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15560078#comment-15560078
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ASF GitHub Bot commented on TRAFODION-2263:
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Github user asfgit closed the pull request at:
https://github.com/apache/incubator-trafodion/pull/749
> Move Similarity check for hive tables to master executor root operator
> ----------------------------------------------------------------------
>
> Key: TRAFODION-2263
> URL: https://issues.apache.org/jira/browse/TRAFODION-2263
> Project: Apache Trafodion
> Issue Type: Improvement
> Reporter: Anoop Sharma
> Assignee: Anoop Sharma
> Priority: Minor
>
> Query plans for hive tables include location of data directories/files
> and the plan depends on it.
> If data changes in a hive file/dir after a query has been compiled and
> before it is executed, then that change is detected at runtime by
> comparing compile time and runtime dir timestamps.
> A mismatch causes that query to recompile using AQR and a new
> plan is generated with latest dir location.
> This detection is currently being done at leaf operators (scan, insert) when
> that operator is executed.
> This jira is to move that check (called Similarity Check) to the root
> operator before starting query execution. That way plan consistency
> checks will be done before running the query and will not depend
> on the actual operator being executed. It will also result in checks not
> being done at various processes and operators like an ESP process.
> All checks will be done at one place in master executor and code will not
> be spread across multiple operators as it is now.
>
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