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https://issues.apache.org/jira/browse/HIVE-27731?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated HIVE-27731:
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Labels: pull-request-available (was: )
> Perform metadata delete when only static filters are present
> ------------------------------------------------------------
>
> Key: HIVE-27731
> URL: https://issues.apache.org/jira/browse/HIVE-27731
> Project: Hive
> Issue Type: Improvement
> Reporter: Sourabh Badhya
> Assignee: Sourabh Badhya
> Priority: Major
> Labels: pull-request-available
>
> When the query has static filters only, try to perform a metadata delete
> directly rather than moving forward with positional delete.
> Some relevant use cases where metadata deletes can be used -
> {code:java}
> DELETE FROM ice_table where id = 1;{code}
> As seen above only filter is (id = 1). If in scenarios wherein the filter
> corresponds to a partition column then metadata delete is more efficient and
> does not generate additional files.
> For partition evolution cases, if it is not possible to perform metadata
> delete then positional delete is done.
> Some other optimisations that can be seen here is utilizing vectorized
> expressions for UDFs which provide vectorized expressions such as year -
> {code:java}
> DELETE FROM ice_table where id = 1 AND year(datecol) = 2015;{code}
> Delete query with Multi-table scans will not optimized using this method
> since determination of where clauses happens at runtime.
> A similar optimisation is seen in Spark where metadata delete is done
> whenever possible-
> [https://github.com/apache/iceberg/blob/master/spark/v3.5/spark/src/main/java/org/apache/iceberg/spark/source/SparkTable.java#L297-L389]
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