CREATE SERVER

Function

CREATE SERVER creates a foreign server.

A foreign server stores OBS server information or other homogeneous cluster information.

Precautions

Only a system administrator and users with permission to use a specified FOREIGN DATA WRAPPER can create a foreign server. The authorization syntax is as follows:

GRANT USAGE ON FOREIGN DATA WRAPPER fdw_name TO username

fdw_name is the name of the FOREIGN DATA WRAPPER, and username is the name of the user creating a foreign server.

When multi-layer quotation marks are used for sensitive columns (such as password and secret_access_key) 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

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CREATE SERVER server_name 
    FOREIGN DATA WRAPPER fdw_name
    OPTIONS ( { option_name ' value ' } [, ...] ) ;

Parameter Description

• server_name

  Specifies the server name.

  Value range: a string containing no more than 63 characters

• FOREIGN DATA WRAPPER fdw_name

  Specifies the name of the foreign data wrapper.

  Value range: fdw_name is the data wrapper created by the system during database initialization. Currently, fdw_name can only be gc_fdw for other homogeneous clusters. You can also create dist_fdw, file_fdw, and log_fdw.

• OPTIONS ( { option_name ' value ' } [, ...] )

  Specifies the parameters for the foreign server. The detailed parameter description is as follows:

  • encrypt

    Specifies whether data is encrypted. This parameter is available only when type is OBS. The default value is on.

    Value range:

    • on indicates that data is encrypted and HTTPS is used for communication.
    • off indicates that data is not encrypted and HTTP is used for communication.
  • access_key

    Specifies the access key (AK) (obtained by users from the OBS console) used for the OBS access protocol. When you create a foreign table, the AK value is encrypted and saved to the metadata table of the database. This parameter is available only when type is set to OBS.

  • secret_access_key

    Specifies the secret key (SK) value (obtained by users from the OBS console) used for the OBS access protocol. When you create a foreign table, the SK value is encrypted and saved to the metadata table of the database. This parameter is available only when type is set to OBS.

Examples

Create my_server, in which file_fdw is the built-in foreign data wrapper.

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-- Create my_server.
gaussdb=# CREATE SERVER my_server FOREIGN DATA WRAPPER file_fdw;

-- Delete my_server.
gaussdb=# DROP SERVER my_server;

Create another server in the homogeneous cluster, where gc_fdw is the foreign data wrapper in the database.

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-- Create a server.
gaussdb=# CREATE SERVER server_remote FOREIGN DATA WRAPPER GC_FDW OPTIONS 
   (address '10.146.187.231:8000,10.180.157.130:8000' ,
  dbname 'test', 
  username 'test', 
  password '********'
);

-- Delete the server.
gaussdb=# DROP SERVER server_remote;

Helpful Links

ALTER SERVER and DROP SERVER