paleolimbot opened a new issue, #844:
URL: https://github.com/apache/arrow-nanoarrow/issues/844

   In #738 we added and tested support for decoding an IPC schema that contains 
dictionary-encoded fields; however, the decoder does not yet provide a way to 
export the dictionary IDs with the schema. We probably need something like:
   
   ```c
   struct ArrowIpcSchemaDictionaries;
   
   ArrowIpcDecoderDecodeSchemaWithDictionaries(struct ArrowIpcDecoder* decoder, 
struct ArrowSchema* schema, struct ArrowIpcSchemaDictionaries*);
   
   ArrowIpcDecoderSetSchemaWithDictionaries(struct ArrowIpcDecoder* decoder, 
struct ArrowSchema* schema, struct ArrowIpcSchemaDictionaries*);
   ```
   
   I was thinking that `ArrowIpcSchemaDictionaries` could be essentially a 
`Vec<(const struct ArrowSchema*, int64_t)>` where the pointers correspond to 
the dictionary pointers in the decoded schema. This allows the setter to locate 
the dictionary IDs when looping over the schema with the downside the pointers 
are invalidated if anybody decides to `ArrowSchemaDeepCopy()`. I'm not also not 
sure there's a better solution in the presence of potentially nested 
dictionaries.


-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]

Reply via email to