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From Sutou Kouhei <>
Subject Re: [C-Glib] - writing an extension array
Date Fri, 27 Nov 2020 03:11:46 GMT

Could you provide the Python script you used and the C
program you used?


  "[C-Glib] - writing an extension array" on Thu, 26 Nov 2020 18:11:53 +0000,
  Ishan Anand <> wrote:

> Hi
> How do you go about implementing an extension type through the C API for Arrow?
> Creating a record batch in python like the example in pyarrow tests [here](,
and reading the resulting schema using the C API, it correctly reads it as an array of the
underlying storage type. The schema along with the metadata can be printed as expected.
> ```
> ext: int64
> -- metadata --
> ARROW:extension:metadata: freq=D
> ARROW:extension:name: test.period
> ```
> However, trying to access the metadata for the schema (obtained with `garrow_schema_get_metadata`)
indicates its size to be 0, which indicates that metadata for the schema isn't the same as
that for a field. Is it possible using the existing API to read/write the metadata for a field?
> Thank you,
> Ishan

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