Error Messages with Unity Catalog

在启用 Unity Catalog 和未启用 Unity Catalog 的集群上重现 SQLAlchemy create_engine 和 execute 的两个案例，并比较报告中显示的连接器错误。追踪 Databricks ServerOperationError 在哪里暴露，并验证未启用 Unity Catalog 的集群会生成更清晰的 UC_NOT_ENABLED 消息，而不是 catalog plugin 错误。

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.