max_connections.
<!--
-$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.75 2001/08/15 18:42:14 momjian Exp $
+$Header: /cvsroot/pgsql/doc/src/sgml/runtime.sgml,v 1.76 2001/09/07 00:46:41 tgl Exp $
-->
<Chapter Id="runtime">
<listitem>
<para>
Determines how many concurrent connections the database server
- will allow. The default is 32. There is also a compiled-in
- hard upper limit on this value, which is typically 1024
- (both numbers can be altered when compiling the server). This
- parameter can only be set at server start.
+ will allow. The default is 32 (unless altered while building
+ the server). This parameter can only be set at server start.
</para>
</listitem>
</varlistentry>
<productname>Postgres</> uses one semaphore per allowed connection
(<option>-N</> option), in sets of 16. Each such set will also
contain a 17th semaphore which contains a <quote>magic
- number</quote>, to avoid collision with semaphore sets used by
+ number</quote>, to detect collision with semaphore sets used by
other applications. The maximum number of semaphores in the system
is set by <varname>SEMMNS</>, which consequently must be at least
as high as the connection setting plus one extra for each 16
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.238 2001/09/07 00:27:29 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/postmaster/postmaster.c,v 1.239 2001/09/07 00:46:42 tgl Exp $
*
* NOTES
*
*/
break;
case 'N':
-
- /*
- * The max number of backends to start. Can't set to less
- * than 1 or more than compiled-in limit.
- */
+ /* The max number of backends to start. */
SetConfigOption("max_connections", optarg, PGC_POSTMASTER, true);
break;
case 'n':
# name = value
#
# (The `=' is optional.) White space is collapsed, comments are
-# introduced by `#' anywhere on a line. The complete list of option
+# introduced by `#' anywhere on a line. The complete list of option
# names and allowed values can be found in the PostgreSQL
-# documentation. Examples are:
-
-#log_connections = on
-#fsync = off
-#max_connections = 64
+# documentation. The commented-out settings shown in this file
+# represent the default values.
# Any option can also be given as a command line switch to the
# postmaster, e.g., 'postmaster -c log_connections=on'. Some options
-# can be set at run-time with the 'SET' SQL command.
+# can be changed at run-time with the 'SET' SQL command.
#========================================================================
#tcpip_socket = false
#ssl = false
-#max_connections = 32 # 1-1024
+#max_connections = 32
#port = 5432
#hostname_lookup = false