Here is a patch to implement this.
Being stuck behind a lock for more than a second is almost
always a problem, so it is reasonable to turn this on by default.
Yours,
Laurenz Albe
From a767e69c724fbbff14114729272be5d29c3d69d8 Mon Sep 17 00:00:00 2001
From: Laurenz Albe <laurenz.a...@cybertec.at>
Date: Thu, 21 Dec 2023 14:24:00 +0100
Subject: [PATCH v1] Default to log_lock_waits=on
If someone is stuck behind a lock for more than a second,
that is almost always a problem that is worth a log entry.
---
doc/src/sgml/config.sgml | 2 +-
src/backend/storage/lmgr/proc.c | 2 +-
src/backend/utils/misc/guc_tables.c | 2 +-
src/backend/utils/misc/postgresql.conf.sample | 2 +-
4 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 44cada2b40..f96ec5a72e 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -7383,7 +7383,7 @@ 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>
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index b6451d9d08..4f25cebbd8 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -60,7 +60,7 @@ int StatementTimeout = 0;
int LockTimeout = 0;
int IdleInTransactionSessionTimeout = 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;
diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index f7c9882f7c..1f3d56e6ee 100644
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -1519,7 +1519,7 @@ struct config_bool ConfigureNamesBool[] =
NULL
},
&log_lock_waits,
- false,
+ true,
NULL, NULL, NULL
},
{
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index cf9f283cfe..451e09d3d8 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -586,7 +586,7 @@
# processes
# %% = '%'
# e.g. '<%u%%%d> '
-#log_lock_waits = off # log lock waits >= deadlock_timeout
+#log_lock_waits = on # log lock waits >= deadlock_timeout
#log_recovery_conflict_waits = off # log standby recovery conflict waits
# >= deadlock_timeout
#log_parameter_max_length = -1 # when logging statements, limit logged
--
2.43.0
