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https://issues.apache.org/jira/browse/ARROW-10406?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17259213#comment-17259213
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Antoine Pitrou commented on ARROW-10406:
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Ah! I thought you were talking about "IPC files" in the general case (i.e. IPC
streams saved in a file) :-)
Well, the problem is, the IPC file format doesn't support dictionary
replacement because it's meant to be readable in random order.
I'm not sure there's an incentive to change it. [~wesm]
> [C++] Support dictionary replacement when writing IPC files
> -----------------------------------------------------------
>
> Key: ARROW-10406
> URL: https://issues.apache.org/jira/browse/ARROW-10406
> Project: Apache Arrow
> Issue Type: New Feature
> Components: C++
> Reporter: Neal Richardson
> Priority: Major
> Fix For: 3.0.0
>
>
> I read a big (taxi) csv file and specified that I wanted to dictionary-encode
> some columns. The resulting Table has ChunkedArrays with 1604 chunks. When I
> go to write this Table to the IPC file format (write_feather), I get an
> error:
> {code}
> Invalid: Dictionary replacement detected when writing IPC file format.
> Arrow IPC files only support a single dictionary for a given field accross
> all batches.
> {code}
> I can write this to Parquet and read it back in, and the roundtrip of the
> data is correct. We should be able to do this in IPC too.
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