It is recommended that you use a connection service file. Refer to "11.2.4 Using a Connection Service File" for details.
Point
If using a connection service file, either of the following methods is available:
Set the service name as a string literal or host variable, as follows:
tcp:postgresql://?service=my_service
Set the service name in the environment variable PGSERVICE, and use CONNECT TO DEFAULT
If a connection service file will not be used, use a literal or variable to specify the connection destination server information for target in the SQL statement below:
EXEC SQL CONNECT TO target [AS connection-name] [USER user-name];
dbname@host1,host2[:[port1][,port2]]
tcp:postgresql://host1,host2[:[port1][,port2]] [/dbname] [?target_server={primary | prefer_standby}][&sslmode=verify-full&sslservercertcn=targetServerCertificateCN]The above format cannot be specified directly without using a literal or variable.
Argument | Explanation |
|---|---|
host1 | Specify the IP address or host name. IPv6 format addresses cannot be specified. |
port1 | Specify the connection destination port numbers, using a comma as the delimiter. |
dbname | Specify the database name. |
target_server | Specify the selection sequence of the servers to which the application will connect. |
sslmode | Specify this to encrypt communications. By default, this is disabled. The setting values for sslmode are as follows: disable: Connect without SSL allow: Connect without SSL, and if it fails, connect with SSL prefer: Connect with SSL, and if it fails, connect without SSL require: Connect always with SSL verify-ca: Connect with SSL, using a certificate issued by a trusted CA (*1) verify-full: Connect with SSL, using a certificate issued by a trusted CA to verify if the server host name matches the certificate (*1) |
sslservercertcn | This parameter is enabled only to perform SSL authentication (sslmode=verify-full). Specify the server certificate CN. If this is omitted, the value will be null, and the server certificate CN will be authenticated using the host name specified in host. |
*1: If specifying either "verify-ca" or "verify-full", use the system environment variable PGSSLROOTCERT (connection parameter sslrootcert) of your operating system to specify the CA certificate file as shown below.
Example)
Variable name: PGSSLROOTCERT
Variable value: cACertificateFile
Point
Environment variables can also be used. Refer to "11.2.5 Using the C Library (libpq)" for information on environment variables.
Note
If using the connection parameter connect_timeout, this value is applied for connections to each of the specified hosts. If both multiplexed database servers have failed, the connection will time out when a time equal to double the connect_timeout value elapses.