jbonofre commented on code in PR #12161: URL: https://github.com/apache/iceberg/pull/12161#discussion_r1938866471
########## format/spec.md: ########## @@ -1400,7 +1400,7 @@ In some cases partition specs are stored using only the field list instead of th The `field-id` property was added for each partition field in v2. In v1, the reference implementation assigned field ids sequentially in each spec starting at 1,000. See Partition Evolution for more details. -In v3 metadata, writers must use only `source-ids` because v3 requires reader support for multi-arg transforms. In v1 and v2 metadata, writers must always write `source-id`; for multi-arg transforms, writers must produce `source-ids` and set `source-id` to the first ID from the field ID list. +In v3 metadata, writers must use only `source-ids` because v3 requires reader support for multi-arg transforms. Review Comment: That's ok but I guess we have to clarify the expectations for the readers. Afair, for the readers, the spec says that if both `source-id` and `source-ids` are provided (in the case of an upgrade from V1/V2 to V3), then `source-id` should be used for single arg transforms and `source-ids` for multi arg transforms. I assume that if `source-id` and `source-ids` are provided in V3 (coming from V1/V2), single arg transforms should use the first element of `source-ids` and ignore `source-id`. I think we should clear the strategy here for the readers as well. -- 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: issues-unsubscr...@iceberg.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@iceberg.apache.org For additional commands, e-mail: issues-h...@iceberg.apache.org
