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https://issues.apache.org/jira/browse/ARROW-7098?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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ASF GitHub Bot updated ARROW-7098:
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    Labels: pull-request-available  (was: )

> [Java] Improve the performance of comparing two memory blocks
> -------------------------------------------------------------
>
>                 Key: ARROW-7098
>                 URL: https://issues.apache.org/jira/browse/ARROW-7098
>             Project: Apache Arrow
>          Issue Type: Improvement
>          Components: Java
>            Reporter: Liya Fan
>            Assignee: Liya Fan
>            Priority: Minor
>              Labels: pull-request-available
>
> We often use the 8-4-1 paradigm to compare two blocks of memory:
> 1. First compare by 8-byte blocks in a loop
> 2. Then compare by 4-byte blocks in a loop
> 3. Last compare by 1-byte blocks in a loop
> It can be proved that the second loop runs at most once. So we can replace 
> the loop with a if statement, which will save us a comparison and two jump 
> operations. 
> According to the discussion in 
> https://github.com/apache/arrow/pull/5508#discussion_r343973982, loop can be 
> expensive. 



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