ALTER DATA SOURCE ​

Function ​

ALTER DATA SOURCE modifies the attributes and content of the data source.

The attributes include the name and owner. The content includes the type, version, and connection options.

Precautions ​

• Only the initial user, system administrator, and owner have the permission to modify data sources.
• To change the owner, the new owner must be the initial user or a system administrator.
• If the password option is displayed, ensure that the datasource.key.cipher and datasource.key.rand files exist in the $\text{GAUSSHOME\_**/bin** directory of each node in openGauss. If the two files do not exist, use the **gs\_guc** tool to generate them and use the **gs\_ssh** tool to release them to the \_}$GAUSSHOME/bin directory on each node.

Syntax ​

ALTER DATA SOURCE src_name
    [TYPE  'type_str']
    [VERSION  {'version_str' | NULL}]
    [OPTIONS ( {[ ADD | SET | DROP ] optname ['optvalue']} [, ...] )];
ALTER DATA SOURCE src_name RENAME TO src_new_name;
ALTER DATA SOURCE src_name OWNER TO new_owner;

Parameter Description ​

• src_name

  Specifies the data source name to be modified.

  Value range: a string. It must comply with the identifier naming convention.

• TYPE

  Changes the original TYPE value of the data source to the specified value.

  Value range: an empty string or a non-empty string

• VERSION

  Changes the original VERSION value of the data source to the specified value.

  Value range: an empty string, a non-empty string, or null

• OPTIONS

  Specifies the column to be added, modified, or deleted. The value of optname should be unique. Comply with the following rules to set this parameter:

  To add a column, you can omit ADD and simply specify the column name, which cannot be an existing column name.

  To modify a column, specify SET and an existing column name.

  To delete a column, specify DROP and an existing column name. Do not set optvalue.

• src_new_name

  Specifies the new data source name.

  Value range: a string. It must comply with the naming convention rule.

• new_user

  Specifies the new owner of an object.

  Value range: a string. It must be a valid username.

Examples ​

-- Create an empty data source.
openGauss=# CREATE DATA SOURCE ds_test1;

-- Rename the data source.
openGauss=# ALTER DATA SOURCE ds_test1 RENAME TO ds_test;

-- Change the owner.
openGauss=# CREATE USER user_test1 IDENTIFIED BY 'Gs@123456';
openGauss=# ALTER USER user_test1 WITH SYSADMIN;
openGauss=# ALTER DATA SOURCE ds_test OWNER TO user_test1;

-- Modify TYPE and VERSION.
openGauss=# ALTER DATA SOURCE ds_test TYPE 'MPPDB_TYPE' VERSION 'XXX';

-- Add a column.
openGauss=# ALTER DATA SOURCE ds_test OPTIONS (add dsn 'gaussdb', username 'test_user');

-- Modify a column.
openGauss=# ALTER DATA SOURCE ds_test OPTIONS (set dsn 'unknown');

-- Delete a column.
openGauss=# ALTER DATA SOURCE ds_test OPTIONS (drop username);

-- Delete the data source and user objects.
openGauss=# DROP DATA SOURCE ds_test;
openGauss=# DROP USER user_test1;

Helpful Links ​

CREATE DATA SOURCE and DROP DATA SOURCE