ALTER EXTERNAL SCHEMA
Function
Modifies EXTERNAL SCHEMA.
![](https://support.huaweicloud.com/eu/devg-dws-v3/public_sys-resources/note_3.0-en-us.png)
Only DWS 3.0 supports the ALTER EXTERNAL SCHEMA syntax.
Syntax
- Modifies an external schema based on the specified name.
1 2 3 4 5 6
ALTER EXTERNAL SCHEMA schema_name WITH SOURCE source_type DATABASE 'db_name' SERVER srv_name METAADDRESS 'address' CONFIGURATION 'confpath';
Parameters
- schema_name
Name of an external schema.
Value range: a string. It must comply with the naming convention.
- The name must be unique,
- and cannot start with pg_.
- SOURCE
Type of the external metadata storage engine. Currently, source_type can only be Hive.
- DATABASE
Hive database corresponding to the external schema.
There is a many-to-one mapping between external schemas and Hive databases.
- SERVER
Value range: an existing foreign server.
You can associate an external schema with a foreign server to access external data.
- METAADDRESS
Hivemetastore communication interface.
- CONFIGURATION
Path for storing hivemetastore configuration files.
![](https://support.huaweicloud.com/eu/devg-dws-v3/public_sys-resources/note_3.0-en-us.png)
If objects in the schema on the current search path are with the same name, specify the schemas different objects are in. You can run the SHOW SEARCH_PATH command to check the schemas on the current search path.
Example
Modify the database and FOREIGN SERVER corresponding to ex1.
1 2 3 |
ALTER EXTERNAL SCHEMA ex1 WITH DATABASE 'hms' SERVER obs_server; |
Feedback
Was this page helpful?
Provide feedbackThank you very much for your feedback. We will continue working to improve the documentation.