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https://issues.apache.org/jira/browse/ARROW-9035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17126099#comment-17126099
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Anthony Abate edited comment on ARROW-9035 at 6/4/20, 5:37 PM:
---------------------------------------------------------------
yes - I didn't realize it was configurable - it probably works but i'll know
soon if it doesnt)
I thought the docs sections were in conflict - but now I realize that 8 byte
alignment is the 'requirement' not 64.. (64 iis still a multiple of 8)
was (Author: abbot):
yes - I didn't realize it was configurable - it probably works but i'll know
soon if it doesnt)
I thought the docs sections were in conflict - but now I realize that 8 byte
alignment is the 'requirement' not 64.. (after 64 iis still a multiple of 8)
> [C++] Writing IPC messages with 64-byte buffer alignment vs. 8-byte default
> ---------------------------------------------------------------------------
>
> 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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