adamreichold opened a new issue, #9600: URL: https://github.com/apache/arrow-rs/issues/9600
**Which part is this question about** How to use the API of `arrow_ipc` and `arrow_array` for delta dictionaries when nested builders are involved. **Describe your question** I have implemented delta dictionaries based on the example at <https://docs.rs/arrow-ipc/latest/arrow_ipc/writer/struct.StreamWriter.html#example---efficient-delta-dictionaries> and this works for top-level columns in my schema by calling `column.finish_preserve_values()` instead of `column.finish()` when collecting the arrays for the next `RecordBatch`. However, I also have nested builders of lists of structs which contain dictionary fields. The type of the top-level build is then `ListBuilder<Box<dyn ArrayBuilder>>` which does not have a `finish_preserve_values` method. How can I produce the top-level array while instructing the `StringDictionaryBuilder` hidden inside the `StructBuilder` inside the `ListBuilder` to preserve its values? -- 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]
