Responsibility of different catalog.

[J0HN50N133]

Currently there are two implemention of CatalogManager: KvBackendCatalogManager and MemoryCatalogManager. I want to know if the following understanding about their responsibility is correct： MemoryCatalogManager should only serve as a placeholder for CatalogManager in testing env or QueryEngine of RegionServer The KvBackendCatalogManager should be held by the frontend to handle logic plan. Then sql text can be transformed into a substrait plan and distributed to the region server. At this point, the region server can simply provide the catalog_list, which is built on the spot, to datafusion for execution.

[killme2008]

Yes, I think you are correct. @waynexia Could you confirm it?

[waynexia]

Precisely 👍 Memory catalog is only for test and region server, and kv backend is for all other use cases.