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https://issues.apache.org/jira/browse/HIVE-4963?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13746535#comment-13746535
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Edward Capriolo commented on HIVE-4963:
---------------------------------------
{quote}
ql/src/java/org/apache/hadoop/hive/ql/exec/PTFPartition.java:89 This I think
you need to do because current RowContainers can only hold crisp java objects.
Seems like we can improve this by writing RowContainer which can hold
writables, thus avoiding unnecessary deserialization and mem-cpy here.
Something worth exploring as follow-up issue.
{quote}
Is it much more work to do this now? There are already a number of PTF
-to-be-cleaned-ups and I would hate to add more.
> Support in memory PTF partitions
> --------------------------------
>
> Key: HIVE-4963
> URL: https://issues.apache.org/jira/browse/HIVE-4963
> Project: Hive
> Issue Type: Bug
> Components: PTF-Windowing
> Reporter: Harish Butani
> Attachments: HIVE-4963.D11955.1.patch, HIVE-4963.D12279.1.patch,
> HIVE-4963.D12279.2.patch, PTFRowContainer.patch
>
>
> PTF partitions apply the defensive mode of assuming that partitions will not
> fit in memory. Because of this there is a significant deserialization
> overhead when accessing elements.
> Allow the user to specify that there is enough memory to hold partitions
> through a 'hive.ptf.partition.fits.in.mem' option.
> Savings depends on partition size and in case of windowing the number of
> UDAFs and the window ranges. For eg for the following (admittedly extreme)
> case the PTFOperator exec times went from 39 secs to 8 secs.
>
> {noformat}
> select t, s, i, b, f, d,
> min(t) over(partition by 1 rows between unbounded preceding and current row),
> min(s) over(partition by 1 rows between unbounded preceding and current row),
> min(i) over(partition by 1 rows between unbounded preceding and current row),
> min(b) over(partition by 1 rows between unbounded preceding and current row)
> from over10k
> {noformat}
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