Updated on 2024-12-18 GMT+08:00

ALTER EXTERNAL SCHEMA

Function

Modifies EXTERNAL SCHEMA. Only 8.2.1.300 and later versions support this syntax.

Syntax

  • Modifies an external schema based on the specified name.
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    ALTER EXTERNAL SCHEMA schema_name 
        WITH [ SOURCE source_name ]
             [ DATABASE 'database_name' ]
             [ SERVER server_name ]
             [ CATALOG 'catalog_name' ]
             [ OPTIONS ( { option_name ' value ' } [, ...] ) ]
             [ METAADDRESS 'address']
             [ CONFIGURATION 'confpath'];
    

Parameter Description

  • schema_name

    Name of the external schema to be modified.

  • SOURCE

    Type of the external metadata storage engine. Currently, source_type can only be dli, lakeformation, or hive.

  • DATABASE

    Database corresponding to the external schema.

  • SERVER

    Value range: an existing foreign server whose type is lf, dli, obs, or hdfs.

    You can associate an external schema with a foreign server to access external data.

  • CATALOG

    Catalog to be accessed in LakeFormation.

  • OPTIONS

    Foreign table parameters. This function is supported only by 8.3.0 and later versions.

    dli_project_id

    Specifies the project ID corresponding to DLI. You can obtain the project ID from the management console. This parameter is available only when the server type is DLI.

  • METAADDRESS

    Hivemetastore communication interface. This parameter is supported only by 9.1.0 and later versions.

  • CONFIGURATION

    Path for storing hivemetastore configuration files. This parameter is supported only by 9.1.0 and later versions.

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.

Examples

Modify the database and FOREIGN SERVER corresponding to ex1.

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ALTER EXTERNAL SCHEMA ex1
    WITH DATABASE 'demo'
         SERVER lf_server;