yangshangqing95 commented on PR #17134: URL: https://github.com/apache/iceberg/pull/17134#issuecomment-4928533508
> Hi @yangshangqing95 , I took a Quick Look and left some comments wrt refactors and the new metadata scan implementation. > > A general note: querying static data such as metadata table names through `SELECT * FROM catalog.db.table.metadata_tables` seems somewhat odd to me. We'd expect the same answer regardless the table we use for the query, right? Anyway, I recall for Iceberg V4 there are consideration to not allow some of the current metadata table and have new ones because the physical representation of a table changes. So this might make sense to have different answers based on the table's version. Let's see what others think! Hi @gaborkaszab thanks for taking a look and leaving the comments! Regarding the metadata table query, I did consider this initially as well. From both an implementation perspective and the current project structure, I’m still leaning toward exposing it under each table, mainly for a few reasons: 1. We don’t currently have a default metadata catalog to store this kind of information, and introducing one just for this metadata feels a bit heavy. 2. Given the current code structure, putting this in `MetadataTableType` keeps the change smaller and less intrusive. 3. There may be more metadata table types in the future, and the supported set could differ across Iceberg versions such as V1, V2, V3, and V4. Keeping this under each table leaves room for future extension, where each table version can expose the metadata tables that are meaningful for it. So from that perspective, it may not necessarily be true that all tables should always return the exact same metadata tables. -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
