*** ./doc/src/sgml/runtime.sgml.orig	2004-02-17 12:06:23.000000000 +0100
--- ./doc/src/sgml/runtime.sgml	2004-02-17 13:10:26.000000000 +0100
***************
*** 2555,2560 ****
--- 2555,2578 ----
        </listitem>
       </varlistentry>
  
+      <varlistentry>
+       <term><varname>wait_for_locks</varname> (<type>string</type>)</term>
+       <listitem>
+        <para>
+         By default an SQL statement has to wait until the desired locks for 
+ 	processing the command can be acquired. In some cases this is not 
+ 	the best thing to do. Therefore it is possible to tell PostgreSQL 
+ 	which locks it is worth waiting for.  The following kinds of locks / 
+ 	settings are supported: all, access share, row share, row exclusive, 
+ 	share update exclusive, share, share row exclusive, exclusive, 
+ 	access exclusive. <quote>all</> is the default setting and means that 
+ 	PostgreSQL will wait for all locks. If <quote>share</> is specified 
+ 	PostgreSQL will not wait for locks which are higher or equal to a 
+ 	share lock.
+        </para>
+       </listitem>
+      </varlistentry>
+ 
       </variablelist>
     </sect2>
  
*** ./src/backend/storage/lmgr/lock.c.orig	2004-02-17 09:45:04.000000000 +0100
--- ./src/backend/storage/lmgr/lock.c	2004-02-17 11:33:13.000000000 +0100
***************
*** 36,41 ****
--- 36,42 ----
  #include "access/xact.h"
  #include "miscadmin.h"
  #include "storage/proc.h"
+ #include "utils/guc.h"
  #include "utils/memutils.h"
  #include "utils/ps_status.h"
  
***************
*** 435,440 ****
--- 436,455 ----
  			 locktag->objId.blkno, lock_mode_names[lockmode]);
  #endif
  
+ 	/* check if NO WAIT has been enabled 
+ 	   the basic strategy is very simple: if the user has selected "all"
+ 	   PostgreSQL will act normally. However, if a certain lock level has
+ 	   been defined PostgreSQL won't wait for locks which are higher than
+ 	   the specified level */
+ 	if	(Wait_for_locks != 0)
+ 	{
+ 		/* now we have to adjust dontWait */
+ 		if	(lockmode >= Wait_for_locks)
+ 		{
+ 			dontWait = true;
+ 		}
+ 	}
+ 
  	/* ???????? This must be changed when short term locks will be used */
  	locktag->lockmethodid = lockmethodid;
  
*** ./src/backend/utils/misc/guc.c.orig	2004-02-17 09:48:34.000000000 +0100
--- ./src/backend/utils/misc/guc.c	2004-02-17 14:42:10.000000000 +0100
***************
*** 47,52 ****
--- 47,53 ----
  #include "storage/fd.h"
  #include "storage/freespace.h"
  #include "storage/lock.h"
+ #include "storage/lmgr.h"
  #include "storage/proc.h"
  #include "tcop/tcopprot.h"
  #include "utils/array.h"
***************
*** 85,90 ****
--- 86,93 ----
  
  static const char *assign_defaultxactisolevel(const char *newval,
  						   bool doit, GucSource source);
+ static const char *assign_wait_for_locks(const char *newval,
+ 						   bool doit, GucSource source);
  static const char *assign_log_min_messages(const char *newval,
  						bool doit, GucSource source);
  static const char *assign_client_min_messages(const char *newval,
***************
*** 132,137 ****
--- 135,141 ----
  int			client_min_messages = NOTICE;
  
  int			log_min_duration_statement = -1;
+ int			Wait_for_locks = 0;
  
  
  /*
***************
*** 149,154 ****
--- 153,159 ----
  static char *client_encoding_string;
  static char *datestyle_string;
  static char *default_iso_level_string;
+ static char *wait_for_locks_string;
  static char *locale_collate;
  static char *locale_ctype;
  static char *regex_flavor_string;
***************
*** 1515,1521 ****
  		&default_iso_level_string,
  		"read committed", assign_defaultxactisolevel, NULL
  	},
! 
  	{
  		{"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
  			gettext_noop("Sets the path for dynamically loadable modules."),
--- 1520,1537 ----
  		&default_iso_level_string,
  		"read committed", assign_defaultxactisolevel, NULL
  	},
! 	{
! 		{"wait_for_locks", PGC_USERSET, CLIENT_CONN_STATEMENT,
! 			gettext_noop("Tells PostgreSQL whether to wait for locks or not."),
! 			gettext_noop("Allowed settings: "
! 				 "\"all\", \"access share\", \"row share\", "
! 				 "\"row exclusive\", \"share update exclusive\", "
! 				 "\"share\", \"share row exclusive\", "
! 				 "\"exclusive\", \"access exclusive\".")
! 		},
! 		&wait_for_locks_string,
! 		"all", assign_wait_for_locks, NULL
! 	},
  	{
  		{"dynamic_library_path", PGC_SUSET, CLIENT_CONN_OTHER,
  			gettext_noop("Sets the path for dynamically loadable modules."),
***************
*** 4457,4462 ****
--- 4473,4533 ----
  #endif
  
  
+ /* in this function we will check if the string in the config-file
+    contains a correct lock level */
+ static const char *
+ assign_wait_for_locks(const char *newval, bool doit, GucSource source)
+ {
+ 	if (strcasecmp(newval, "all") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = NoLock;
+ 	}
+ 	else if (strcasecmp(newval, "access share") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = AccessShareLock;
+ 	}
+ 	else if (strcasecmp(newval, "row share") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = RowShareLock;
+ 	}
+ 	else if (strcasecmp(newval, "row exclusive") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = RowExclusiveLock;
+ 	}
+ 	else if (strcasecmp(newval, "share update exclusive") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = ShareUpdateExclusiveLock;
+ 	}
+ 	else if (strcasecmp(newval, "share") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = ShareLock;
+ 	}
+ 	else if (strcasecmp(newval, "share row exclusive") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = ShareRowExclusiveLock;
+ 	}
+ 	else if (strcasecmp(newval, "exclusive") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = ExclusiveLock;
+ 	}
+ 	else if (strcasecmp(newval, "access exclusive") == 0)
+ 	{
+ 		if (doit)
+ 			Wait_for_locks = AccessExclusiveLock;
+ 	}
+ 	else
+ 		return NULL;
+ 	return newval;
+ }
+ 
  static const char *
  assign_defaultxactisolevel(const char *newval, bool doit, GucSource source)
  {
*** ./src/backend/utils/misc/postgresql.conf.sample.orig	2004-02-17 11:02:35.000000000 +0100
--- ./src/backend/utils/misc/postgresql.conf.sample	2004-02-17 13:38:14.000000000 +0100
***************
*** 248,253 ****
--- 248,257 ----
  # LOCK MANAGEMENT
  #---------------------------------------------------------------------------
  
+ #wait_for_locks = 'all'		# allowed settings: all, access share, 
+ 				#  row share, row exclusive, share update 
+ 				#  exclusive, share, share row exclusive,
+ 				#  exclusive, access exclusive
  #deadlock_timeout = 1000	# in milliseconds
  #max_locks_per_transaction = 64	# min 10, ~260*max_connections bytes each
  
*** ./src/bin/psql/tab-complete.c.orig	2004-02-17 11:51:19.000000000 +0100
--- ./src/bin/psql/tab-complete.c	2004-02-17 11:51:54.000000000 +0100
***************
*** 567,572 ****
--- 567,573 ----
  		"unix_socket_directory",
  		"unix_socket_group",
  		"unix_socket_permissions",
+ 		"wait_for_locks",
  		"wal_buffers",
  		"wal_debug",
  		"wal_sync_method",
*** ./src/include/storage/lock.h.orig	2004-02-17 10:12:37.000000000 +0100
--- ./src/include/storage/lock.h	2004-02-17 10:16:51.000000000 +0100
***************
*** 32,37 ****
--- 32,45 ----
  
  extern int	max_locks_per_xact;
  
+ 
+ /* PostgreSQL supports NO WAIT via GUC variables 
+    therefore we need information telling us whether we want to wait for locks or
+    not. In addition to that we want to tell the system for which locks we want
+    to wait */
+ extern int  Wait_for_locks;
+ 
+ 
  #ifdef LOCK_DEBUG
  extern int	Trace_lock_oidmin;
  extern bool Trace_locks;
*** ./src/include/utils/guc.h.orig	2004-02-17 10:35:02.000000000 +0100
--- ./src/include/utils/guc.h	2004-02-17 10:35:29.000000000 +0100
***************
*** 126,131 ****
--- 126,132 ----
  extern int	log_min_messages;
  extern int	client_min_messages;
  extern int	log_min_duration_statement;
+ extern int	Wait_for_locks;
  
  
  extern void SetConfigOption(const char *name, const char *value,