hostaddr

Numeric IP address of host to connect to. This should be in the standard IPv4 address format, e.g., 172.28.40.9 . If your machine supports IPv6, you can also use those addresses. TCP/IP communication is always used when a nonempty string is specified for this parameter. If this parameter is not specified, the value of host will be looked up to find the corresponding IP address — or, if host specifies an IP address, that value will be used directly.

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Client library: libpq 18.6
Manual definition: Documented
Source environment fallback: PGHOSTADDR
Compiled fallback expression: NULL
documented: true
environment: map[description:PGHOSTADDR behaves the same as the hostaddr connection parameter. This can be set instead of or in addition to PGHOST to avoid DNS lookup overhead. name:PGHOSTADDR source_url:/docs/18/libpq-envars.html]
keyword: hostaddr
manual path: libpq-connect.html#LIBPQ-CONNECT-HOSTADDR
signature: hostaddr

版本定义 PG 18

hostaddr

Numeric IP address of host to connect to. This should be in the standard IPv4 address format, e.g., 172.28.40.9. If your machine supports IPv6, you can also use those addresses. TCP/IP communication is always used when a nonempty string is specified for this parameter. If this parameter is not specified, the value of host will be looked up to find the corresponding IP address — or, if host specifies an IP address, that value will be used directly.

Using hostaddr allows the application to avoid a host name look-up, which might be important in applications with time constraints. However, a host name is required for GSSAPI or SSPI authentication methods, as well as for verify-full SSL certificate verification. The following rules are used:

If host is specified without hostaddr, a host name lookup occurs. (When using PQconnectPoll, the lookup occurs when PQconnectPoll first considers this host name, and it may cause PQconnectPoll to block for a significant amount of time.)
If hostaddr is specified without host, the value for hostaddr gives the server network address. The connection attempt will fail if the authentication method requires a host name.
If both host and hostaddr are specified, the value for hostaddr gives the server network address. The value for host is ignored unless the authentication method requires it, in which case it will be used as the host name.

Note that authentication is likely to fail if host is not the name of the server at network address hostaddr. Also, when both host and hostaddr are specified, host is used to identify the connection in a password file (see Section 32.16).

A comma-separated list of hostaddr values is also accepted, in which case each host in the list is tried in order. An empty item in the list causes the corresponding host name to be used, or the default host name if that is empty as well. See Section 32.1.1.3 for details.

Without either a host name or host address, libpq will connect using a local Unix-domain socket; or on Windows, it will attempt to connect to localhost.

Environment fallback

Variable	Documented behavior
PGHOSTADDR	PGHOSTADDR behaves the same as the hostaddr connection parameter. This can be set instead of or in addition to PGHOST to avoid DNS lookup overhead.

比较版本

完整来源事实

default evidence

A comma-separated list of hostaddr values is also accepted, in which case each host in the list is tried in order. An empty item in the list causes the corresponding host name to be used, or the default host name if that is empty as well. See Section 32.1.1.3 for details.

precedence evidence

The following environment variables can be used to select default connection parameter values, which will be used by PQconnectdb , PQsetdbLogin and PQsetdb if no value is directly specified by the calling code. These are useful to avoid hard-coding database connection information into simple client applications, for example., Service names can be defined in either a per-user service file or a system-wide file. If the same service name exists in both the user and the system file, the user file takes precedence. By default, the per-user service file is named ~/.pg_service.conf . On Microsoft Windows, it is named %APPDATA%\postgresql\.pg_service.conf (where %APPDATA% refers to the Application Data subdirectory in the user's profile). A different file name can be specified by setting the environment variable PGSERVICEFILE . The system-wide file is named pg_service.conf . By default it is sought in the etc directory of the PostgreSQL installation (use pg_config --sysconfdir to identify this directory precisely). Another directory, but not a different file name, can be specified by setting the environment variable PGSYSCONFDIR ., Connection parameters obtained from a service file are combined with parameters obtained from other sources. A service file setting overrides the corresponding environment variable, and in turn can be overridden by a value given directly in the connection string. For example, using the above service file, a connection string service=mydb port=5434 will use host somehost , port 5434 , user admin , and other parameters as set by environment variables or built-in defaults.

source option

{"compiled_default_expression":"NULL","declaration":"\"hostaddr\", \"PGHOSTADDR\", NULL, NULL, \"Database-Host-IP-Address\", \"\", 45, offsetof(struct pg_conn, pghostaddr)","environment":"PGHOSTADDR","keyword":"hostaddr","source_notes":[]}

来源引用

完整定义与证据 JSON

定义来源

center · PostgreSQL 18 · ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8

正文语言: en · ee8d1a3612338fd9adf250730cb640fcc5233b5491337cc00a316a44e3a0b9f8