[ https://issues.apache.org/jira/browse/ARROW-9035?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17126062#comment-17126062 ]
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 ? -- This message was sent by Atlassian Jira (v8.3.4#803005)