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https://issues.apache.org/jira/browse/ARROW-9035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17126062#comment-17126062
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Wes McKinney commented on ARROW-9035:
-------------------------------------

It's supposed to be configurable

https://github.com/apache/arrow/blob/master/cpp/src/arrow/ipc/options.h#L47

I don't know if this configuration parameter is respected though. It's a big 
project and there are only so many helping hands. 

> 8 vs 64 byte alignment
> ----------------------
>
>                 Key: ARROW-9035
>                 URL: https://issues.apache.org/jira/browse/ARROW-9035
>             Project: Apache Arrow
>          Issue Type: Bug
>          Components: C++, Documentation
>    Affects Versions: 0.17.0
>            Reporter: Anthony Abate
>            Priority: Minor
>
> I used the C++ library to create a very small arrow file (1 field of 5 int32) 
> and was surprised that the buffers are not aligned to 64 bytes as per the 
> documentation section "Buffer Alignment and Padding" with examples.. based on 
> the examples there, the 20 bytes of int32 should be padded to 64 bytes, but 
> it is only 24 (see below) .   
> extract message metadata - see BodyLength = 24
> {code:java}
> {
>   version: "V4",
>   header_type: "RecordBatch",
>   header: {
>     nodes: [
>       {
>         length: 5,
>         null_count: 0
>       }
>     ],
>     buffers: [
>       {
>         offset: 0,
>         length: 0
>       },
>       {
>         offset: 0,
>         length: 20
>       }
>     ]
>   },
>   bodyLength: 24
> } {code}
> Reading further down the documentation section "Encapsulated message format" 
> it says serialization should use 8 byte alignment. 
> These both seem at odds with each other and some clarification is needed.
> Is the documentation wrong? 
> Or
> Should 8 byte alignment be used for File and 64 byte for IPC ?



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