dengzhhu653 commented on PR #6088: URL: https://github.com/apache/hive/pull/6088#issuecomment-3489161909
Sorry for the late reply. Took a quick overview of the changes, looks we introduce a new syntax for the catalog, as well as the future items: >The code related to cat.db.tbl (part of the work in [HIVE-29177](https://issues.apache.org/jira/browse/HIVE-29177)) will also involve many table-related interfaces, which presents certain refactoring challenges. > let's further explore this issue when we work on cross-catalog queries. An already created ticket, [HIVE-29242](https://issues.apache.org/jira/browse/HIVE-29242), can be used to track this matter. It seems to me this is a significant/big change, and the user should follow a new way of catalog.db.table to request the table as the Trino/Presto does today. I think we can have a more simple idea, let's push the catalog awareness down into the Metastore client. For example, SET CATALOG testcat; -> change to a metaconf change, set metaconf:hive.metastore.current.catalog = testcat, default hive, this configuration will be propagated to HMS, every HMS API request will be appended with the `testcat`, both client and server can handle it. For cross-catalog queries, we can also do it in a similar way, we can introduce a new catalog awareness lawyer between session client and the thrift client, as SessionHiveMetaStoreClient -> CatalogAwarenessMetastoreClient -> ThriftHiveMetaStoreClient. The CatalogAwarenessMetastoreClient can acknowledge of the catalog through configuration or properties stored in HMS(HIVE-27186). Something as `hive.matastore.catalog.mapping.pattern`=`iceberg_catalog`:`ice_db1*,hive_db1,hive_db2.ice_tab*`;`hive`:`default,acid_db*`, the CatalogAwarenessMetastoreClient even can point to a third-party catalog partner. By this way, we don't need to introduce the change on the Hive SQL syntax and test it throughly, and other engines(such as Impala) can also benefit from this way to add the support on cross-catalog queries. -- 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]
