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https://issues.apache.org/jira/browse/HIVE-4963?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13741670#comment-13741670
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Edward Capriolo commented on HIVE-4963:
---------------------------------------

Why cant we mark the fields as transient? Do they need to be serialized in 
other contexts? If they need to be serialized sometimes and not others maybe 
what we need is two different fields?
                
> 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, 
> 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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