etseidl commented on PR #11157: URL: https://github.com/apache/arrow-rs/pull/11157#issuecomment-5834422727
Now that I've changed it, I'm not really happy with the merging behavior on subsequent calls to `read_page_indexes` (C11). Saving the old page index requires a nested loop over `num_row_groups X num_columns` elements, cloning any that exist. In the worst case of an existing fully populated page index, we're inefficiently cloning the entire thing, and then potentially re-decoding the entire structure and throwing away the clone. Also, this really complicated the `Grid` case because the original selection is not known via the provider interface, so we still have to do the full quadratic scan. I think it might be cleaner to just document that `read_page_indexes` will overwrite the page index in it's entirety, and if incremental builds are desired, one should provide their own `PageIndexProvider` and handle populating it themselves. Then we can modify `parse_page_index` to set the page index to `None` when both policies are `Skip`. Thoughts? cc @alamb -- 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]
