ALTER USER MAPPING

Function

ALTER USER MAPPING changes the definition of a user mapping.

Precautions

If the password option is displayed, ensure that the usermapping.key.cipher and usermapping.key.rand files exist in the $GAUSSHOME/bin directory of each node in GaussDB. If the two files do not exist, use the gs\_guc tool to generate them and use the gs\_ssh tool to release them to the $GAUSSHOME/bin directory on each node.

When multi-layer quotation marks are used for sensitive columns (such as password) in OPTIONS, the semantics is different from that in the scenario where quotation marks are not used. Therefore, sensitive columns are not identified for anonymization.

Syntax

ALTER USER MAPPING FOR { user_name | USER | CURRENT_USER | PUBLIC }
    SERVER server_name
    OPTIONS ( [ ADD | SET | DROP ] option ['value'] [, ... ] )

In OPTIONS, ADD, SET, and DROP are operations to be performed. If these operations are not specified, ADD operations will be performed by default. option and value are the parameters and values of the corresponding operation.

Parameter Description

• user_name

  Specifies user name of the mapping.

  CURRENT_USER and USER match the name of the current user. PUBLIC is used to match all current and future user names in the system.

• server_name

  Specifies name of the server to which the user is mapped.

• OPTIONS

  Changes an option for the user mapping. The new option overwrites any previously specified option. ADD, SET, and DROP are operations to be performed. If the operation is not set explicitly, ADD is used. The option name must be unique and will be validated with the foreign data wrapper of the server.

Helpful Links

CREATE USER MAPPING and DROP USER MAPPING