Rewrite docs for new libpq keepalive parameters.

The revised documentation makes it more clear that these are client-side
parameters, rather than server side parameters.  It also puts the main
point of each parameter first, and consolidates the conditions under which
it might be ignored in a single list at the end.

diff --git a/doc/src/sgml/libpq.sgml b/doc/src/sgml/libpq.sgml
index 11161d993f5923f0c5c87d7ff447ad152b95c384..460e4ecd5101365842fd0fc9fcb663f8e15f0ea1 100644 (file)
--- a/doc/src/sgml/libpq.sgml
+++ b/doc/src/sgml/libpq.sgml
@@ -1,4 +1,4 @@
-
+
 
 
  <application>libpq</application> - C Library
@@ -284,10 +284,10 @@
          keepalives
          
           
-           Controls whether TCP keepalives are used. The default value is 1,
-           meaning on, but you can change this to 0, meaning off, if keepalives
-           are not wanted.  This parameter is ignored for connections made via
-           a Unix-domain socket.
+           Controls whether client-side TCP keepalives are used. The default
+           value is 1, meaning on, but you can change this to 0, meaning off,
+           if keepalives are not wanted.  This parameter is ignored for
+           connections made via a Unix-domain socket.
           
          
         
@@ -296,11 +296,12 @@
          keepalives_idle
          
           
-           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 zero uses the system
-           default.  This parameter is ignored for connections made via a
-           Unix-domain socket, or if keepalives are disabled.
+           Controls the number of seconds of inactivity after which TCP should
+           send a keepalive message to the server.  A value of zero uses the
+           system default.  This parameter is ignored if the
+           TCP_KEEPIDLE socket option is not supported, for
+           connections made via a Unix-domain socket, or if keepalives are
+           disabled.
           
          
         
@@ -309,11 +310,12 @@
          keepalives_interval
          
           
-           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 zero uses the system
-           default.  This parameter is ignored for connections made via a
-           Unix-domain socket, or if keepalives are disabled.
+           Controls the number of seconds after which a TCP keepalive message
+           that is not acknowledged by the server should be retransmitted.  A
+           value of zero uses the system default.  This parameter is ignored if
+           the TCP_KEEPINTVL socket option is not supported, for
+           connections made via a Unix-domain socket, or if keepalives are
+           disabled.
           
          
         
@@ -322,11 +324,12 @@
          keepalives_count
          
           
-           On systems that support the TCP_KEEPCNT socket
-           option, specifies how many keepalives can be lost before the
-           connection is considered dead. A value of zero uses the system
-           default.  This parameter is ignored for connections made via a
-           Unix-domain socket, or if keepalives are disabled.
+           Controls the number of TCP keepalives that can be lost before the
+           client's connection to the server is considered dead.  A value of
+           zero uses the system default.  This parameter is ignored if the
+           TCP_KEEPCNT socket option is not supported, for
+           connections made via a Unix-domain socket, or if keepalives are
+           disabled.