morningman commented on issue #4051: URL: https://github.com/apache/incubator-doris/issues/4051#issuecomment-666893332
> Why not change it to 'Merge on Write'? It can be done in some other new data model in future. Changing the current data model to "Copy-on-Write" is a very costly thing. Having you any idea about it? > I see that this function support all the load interface. And insert data and delete data in one batch, how can user delete data without value column? Actually, I think the value column can be filled by some dummy placeholder values. And user can also specify the column mappings in `columns` properties to specified the key columns, and the missing value columns can either will filled by default value automatically, or filled by user manually. > Even this function is only for unique model, however this is a "user-interface" level function. We should discuss from a more macroscopic and creative perspective, not the immediate function. If this function is only for unique model, what's the function about duplicate and aggregate model? Oh, I forgot, uniq key is also a kind of aggr key model, so this can be performed on aggr key model in some scenarios. It is just like `DELETE FROM` method that system will check if all key columns exists in rollups or materialized views. Duplicate key model is not within our consideration. Cause we do not found a good way to handle this model. First of all, the main purpose of this delete function is to receive the data changes of the TP system captured by the CDC system. The data in the TP system usually has the concept of a primary key. And many CDC systems or data transmission systems themselves also require data to have a primary key, otherwise effective incremental data capture cannot be performed. In my opinion, duplicate key is not a data model for strict CRUD scenarios. ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org
