Error Messages with Unity Catalog

在啟用 Unity Catalog 與未啟用 Unity Catalog 的叢集上重現 SQLAlchemy create_engine 和 execute 的兩個案例，並比較報告中顯示的連接器錯誤。追蹤 Databricks ServerOperationError 在哪裡暴露，並驗證未啟用 Unity Catalog 的叢集會產生更清楚的 UC_NOT_ENABLED 訊息，而不是 catalog plugin 錯誤。

On older versions of the connector (version 2.5.2) and connecting to a cluster where unity catalog is not enabled, it would give us the first failure message. However, after updating to the connector (version 2.9.3) and connecting to unity catalog enabled cluster, it's giving us a different error message, which doesn't help figure out what the issue is.

from sqlalchemy import create_engine

# Unity Catalog enabled
uc_eng = create_engine(f"databricks://{CONNECTION_STRING}?catalog=prod", connect_args={'http_path': f'sql/protocolv1/o/{WORKSPACE_ID}/{UC_CLUSTER_ID}'})
uc_eng.execute(f"select * from {TABLE_NAME} limit 1").fetchall()  # works

# NOT Unity Catalog ENABLED 
non_uc_eng = create_engine(f"databricks://{CONNECTION_STRING}?catalog=prod", connect_args={'http_path': f'sql/protocolv1/o/{WORKSPACE_ID}/{NON_UC_CLUSTER_ID}'})
non_uc_eng.execute("select * from {TABLE_NAME} limit 1").fetchall(). # fails 


Failure message:
DatabaseError: (databricks.sql.exc.ServerOperationError) Catalog 'prod' plugin class not found: spark.sql.catalog.prod is not defined
[SQL: select * from prod.{TABLE_NAME} limit 1]
(Background on this error at: http://sqlalche.me/e/13/4xp6)
instead of former:
sqlalchemy.exc.DatabaseError: (databricks.sql.exc.ServerOperationError) [UC_NOT_ENABLED] Unity Catalog is not enabled on this cluster.