Hi, Could you provide the Python script you used and the C program you used?
Thanks, -- kou In <cs1pr8401mb082208b574a83aff774f617ceb...@cs1pr8401mb0822.namprd84.prod.outlook.com> "[C-Glib] - writing an extension array" on Thu, 26 Nov 2020 18:11:53 +0000, Ishan Anand <[email protected]> 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](https://github.com/apache/arrow/blob/2a5f92455ec4f9788ee96fa209b38d76bd927196/python/pyarrow/tests/test_extension_type.py#L375), > 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
