- listen_addresses (string)
Specifies the TCP/IP address(es) on which the server is
to listen for connections from client applications.
The value takes the form of a comma-separated list of host names
and/or numeric IP addresses. The special entry *
corresponds to all available IP interfaces.
If the list is empty, the server does not listen on any IP interface
at all, in which case only Unix-domain sockets can be used to connect
to it.
The default value is localhost,
which allows only local "loopback" connections to be made.
This parameter can only be set at server start.
- port (integer)
The TCP port the server listens on; 5432 by default. Note that the
same port number is used for all IP addresses the server listens on.
This parameter can only be set at server start.
- max_connections (integer)
Determines the maximum number of concurrent connections to the
database server. The default is typically 100, but may be less
if your kernel settings will not support it (as determined
during initdb). This parameter can only be
set at server start.
Increasing this parameter may cause PostgreSQL
to request more System V shared
memory or semaphores than your operating system's default configuration
allows. See Section 16.4.1 for information on how to
adjust those parameters, if necessary.
- superuser_reserved_connections
(integer)
Determines the number of connection "slots" that
are reserved for connections by PostgreSQL
superusers. At most max_connections
connections can ever be active simultaneously. Whenever the
number of active concurrent connections is at least
max_connections minus
superuser_reserved_connections, new
connections will be accepted only for superusers.
The default value is 2. The value must be less than the value of
max_connections. This parameter can only be
set at server start.
- unix_socket_directory (string)
Specifies the directory of the Unix-domain socket on which the
server is to listen for
connections from client applications. The default is normally
/tmp, but can be changed at build time.
This parameter can only be set at server start.
- unix_socket_group (string)
Sets the owning group of the Unix-domain socket. (The owning
user of the socket is always the user that starts the
server.) In combination with the option
unix_socket_permissions this can be used as
an additional access control mechanism for Unix-domain connections.
By default this is the empty string, which uses the default
group for the current user. This option can only be set at
server start.
- unix_socket_permissions (integer)
Sets the access permissions of the Unix-domain socket. Unix-domain
sockets use the usual Unix file system permission set.
The option value is expected to be a numeric mode
specification in the form accepted by the
chmod and umask
system calls. (To use the customary octal format the number
must start with a 0 (zero).)
The default permissions are 0777, meaning
anyone can connect. Reasonable alternatives are
0770 (only user and group, see also
unix_socket_group) and 0700
(only user). (Note that for a Unix-domain socket, only write
permission matters and so there is no point in setting or revoking
read or execute permissions.)
This access control mechanism is independent of the one
described in Chapter 20.
This option can only be set at server start.
- bonjour_name (string)
Specifies the Bonjour broadcast
name. By default, the computer name is used, specified as an
empty string ''. This option is ignored if the server was not
compiled with Bonjour support. This
option can only be set at server start.
- tcp_keepalives_idle (integer)
On systems that support the TCP_KEEPIDLE socket option, specifies the
number of seconds between sending keepalives on an otherwise idle
connection. A value of 0 uses the system default. If TCP_KEEPIDLE is
not supported, this parameter must be 0. This option is ignored for
connections made via a Unix-domain socket.
- tcp_keepalives_interval (integer)
On systems that support the TCP_KEEPINTVL socket option, specifies how
long, in seconds, to wait for a response to a keepalive before
retransmitting. A value of 0 uses the system default. If TCP_KEEPINTVL
is not supported, this parameter must be 0. This option is ignored
for connections made via a Unix-domain socket.
- tcp_keepalives_count (integer)
On systems that support the TCP_KEEPCNT socket option, specifies how
many keepalives may be lost before the connection is considered dead.
A value of 0 uses the system default. If TCP_KEEPCNT is not
supported, this parameter must be 0. This option is ignored
for connections made via a Unix-domain socket.
