v1-0001-Lower-vacuum_cost_page_miss-s-default-to-3.patch

From 7a134cb88e43f8f9eb8e9c1ee925bf2f68b115a9 Mon Sep 17 00:00:00 2001
From: Peter Geoghegan <pg@bowt.ie>
Date: Wed, 13 Jan 2021 16:18:06 -0800
Subject: [PATCH v1] Lower vacuum_cost_page_miss's default to 3.

---
 src/backend/utils/init/globals.c              | 2 +-
 src/backend/utils/misc/guc.c                  | 2 +-
 src/backend/utils/misc/postgresql.conf.sample | 2 +-
 doc/src/sgml/config.sgml                      | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index ea28769d6a..083c89f84e 100644
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -137,7 +137,7 @@ int			max_parallel_workers = 8;
 int			MaxBackends = 0;
 
 int			VacuumCostPageHit = 1;	/* GUC parameters for vacuum */
-int			VacuumCostPageMiss = 10;
+int			VacuumCostPageMiss = 3;
 int			VacuumCostPageDirty = 20;
 int			VacuumCostLimit = 200;
 double		VacuumCostDelay = 0;
diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 17579eeaca..2c60e03e0e 100644
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -2413,7 +2413,7 @@ static struct config_int ConfigureNamesInt[] =
 			NULL
 		},
 		&VacuumCostPageMiss,
-		10, 0, 10000,
+		3, 0, 10000,
 		NULL, NULL, NULL
 	},
 
diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 8930a94fff..fc0377f673 100644
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -164,7 +164,7 @@
 
 #vacuum_cost_delay = 0			# 0-100 milliseconds (0 disables)
 #vacuum_cost_page_hit = 1		# 0-10000 credits
-#vacuum_cost_page_miss = 10		# 0-10000 credits
+#vacuum_cost_page_miss = 3		# 0-10000 credits
 #vacuum_cost_page_dirty = 20		# 0-10000 credits
 #vacuum_cost_limit = 200		# 1-10000 credits
 
diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index 82864bbb24..cad75b6ef8 100644
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -2116,7 +2116,7 @@ include_dir 'conf.d'
          The estimated cost for vacuuming a buffer that has to be read from
          disk.  This represents the effort to lock the buffer pool,
          lookup the shared hash table, read the desired block in from
-         the disk and scan its content. The default value is 10.
+         the disk and scan its content. The default value is 3.
         </para>
        </listitem>
       </varlistentry>
-- 
2.27.0