ALTER SERVER

Function

ALTER SERVER adds, modifies, or deletes the parameters of an existing server. You can query existing servers from the pg_foreign_server system catalog. The current feature is a lab feature. Contact Huawei technical support before using it.

Precautions

Only the server owner or a user granted with the ALTER permission can run the ALTER SERVER command. The system administrator has this permission by default. 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 name of a foreign server.

ALTER SERVER server_name     
   RENAME TO new_name;

Parameter Description

server_name

Specifies the name of the server to be modified.
new_version

Specifies the new version of the server.
OPTIONS

Change 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, including the time to establish a connection, analyze the request at the remote server, and generate a plan. The default value is 100.
- fdw_typle_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.