[CF 4718] v2 - Set log_lock_waits=on by default

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https://commitfest.postgresql.org/patch/4718

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Patch(es): https://www.postgresql.org/message-id/[email protected]
Author(s): Laurenz Albe

Author: Commitfest Bot

doc/src/sgml/config.sgml

@@ -7929,7 +7929,7 @@ log_line_prefix = '%m [%p] %q%u@%d/%a '
         Controls whether a log message is produced when a session waits
         longer than <xref linkend="guc-deadlock-timeout"/> to acquire a
         lock.  This is useful in determining if lock waits are causing
-        poor performance.  The default is <literal>off</literal>.
+        poor performance.  The default is <literal>on</literal>.
         Only superusers and users with the appropriate <literal>SET</literal>
         privilege can change this setting.
        </para>

src/backend/storage/lmgr/proc.c

@@ -60,7 +60,7 @@ int			LockTimeout = 0;
 int			IdleInTransactionSessionTimeout = 0;
 int			TransactionTimeout = 0;
 int			IdleSessionTimeout = 0;
-bool		log_lock_waits = false;
+bool		log_lock_waits = true;
 
 /* Pointer to this process's PGPROC struct, if any */
 PGPROC	   *MyProc = NULL;

src/backend/utils/misc/guc_parameters.dat

@@ -566,7 +566,7 @@
 { name => 'log_lock_waits', type => 'bool', context => 'PGC_SUSET', group => 'LOGGING_WHAT',
   short_desc => 'Logs long lock waits.',
   variable => 'log_lock_waits',
-  boot_val => 'false',
+  boot_val => 'true',
 },
 
 { name => 'log_lock_failures', type => 'bool', context => 'PGC_SUSET', group => 'LOGGING_WHAT',

src/backend/utils/misc/postgresql.conf.sample

@@ -624,7 +624,7 @@
 					#        processes
 					#   %% = '%'
 					# e.g. '<%u%%%d> '
-#log_lock_waits = off			# log lock waits >= deadlock_timeout
+#log_lock_waits = on			# log lock waits >= deadlock_timeout
 #log_lock_failures = off		# log lock failures
 #log_recovery_conflict_waits = off	# log standby recovery conflict waits
 					# >= deadlock_timeout