ALTER SERVER

Description

Adds, modifies, or deletes the parameters of an existing server. You can query existing servers from the pg_foreign_server system catalog.

Precautions

Only the server owner or a user granted with the ALTER permission can run the ALTER SERVER command. By default, system administrators have the permission. To modify a server owner, you must be the server owner or system administrator and a member of the new owner role.
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

Change the parameters for a foreign server.
```
 ALTER SERVER server_name [ VERSION 'new_version' ]   
      [ 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 of the corresponding operation.

Change the owner of a foreign server.

      
           ALTER SERVER server_name 
    OWNER TO new_owner;

Change the name of a foreign server.

ALTER SERVER server_name     
   RENAME TO new_name;

Parameters

server_name

Specifies the name of the server to be modified.
new_version

Specifies the new version of the server.
OPTIONS

Changes options of the server. 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 the name and value are also validated with the foreign data wrapper library of the server.
In addition to the connection parameters supported by libpq, the following parameters are provided:
- fdw_startup_cost
  
  Estimates the startup time required for a foreign table scan. This value usually contains the time taken to establish a connection, analyze the request at the remote end, and generate a plan. The default value is 100. The value is a real number greater than 0.
- fdw_tuple_cost
  
  Specifies the additional consumption when each tuple is scanned on a remote server. The value specifies the extra consumption of data transmission between servers. The default value is 0.01. The value is a real number greater than 0.

new_name

Specifies the new name of the server.

Examples

-- Create my_server.
gaussdb=# CREATE SERVER my_server FOREIGN DATA WRAPPER log_fdw;
 
-- Change the name of an external service.
gaussdb=# ALTER SERVER my_server RENAME TO my_server_1;
 
-- Delete my_server_1.
gaussdb=# DROP SERVER my_server_1;