Revert "Increase the default vacuum_cost_limit from 200 to 2000"

This reverts commit bd09503e633b8077822bb4daf91625b71ac16253.

Per discussion, it seems like what we should do instead is to
reduce the default value of autovacuum_vacuum_cost_delay by the
same factor.  That's functionally equivalent as long as the
platform can accurately service the smaller delay request, which
should be true on anything released in the last 10 years or more.
And smaller, more-closely-spaced delays are better in terms of
providing a steady I/O load.

Discussion: https://postgr.es/m/28720.1552101086@sss.pgh.pa.us

diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml
index c12170b4b63dcfd79d3f5e6d7d012026708c1f3d..00664cd83ee43994c0d41a818c00027476d54696 100644 (file)
--- a/doc/src/sgml/config.sgml
+++ b/doc/src/sgml/config.sgml
@@ -1932,7 +1932,7 @@ include_dir 'conf.d'
        <listitem>
         <para>
          The accumulated cost that will cause the vacuuming process to sleep.
-         The default value is 2000.
+         The default value is 200.
         </para>
        </listitem>
       </varlistentry>

diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c
index 6d1e94f81717cb5aa898464bb17b85387d187dea..a5950c1e8c2bf939de0250fde581521604064bc1 100644 (file)
--- a/src/backend/utils/init/globals.c
+++ b/src/backend/utils/init/globals.c
@@ -137,7 +137,7 @@ int                 MaxBackends = 0;
 int                    VacuumCostPageHit = 1;  /* GUC parameters for vacuum */
 int                    VacuumCostPageMiss = 10;
 int                    VacuumCostPageDirty = 20;
-int                    VacuumCostLimit = 2000;
+int                    VacuumCostLimit = 200;
 double         VacuumCostDelay = 0;
 
 int                    VacuumPageHit = 0;

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index 6e396f1598f99b92ab32855765179e24e6767323..c82804b1b95dceeabdfb4bc66f43e90b6ba568d8 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -2265,7 +2265,7 @@ static struct config_int ConfigureNamesInt[] =
                        NULL
                },
                &VacuumCostLimit,
-               2000, 1, 10000,
+               200, 1, 10000,
                NULL, NULL, NULL
        },
 

diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index 417f00a8419fed8bf1edfd78bfc2ece8e58134f6..6f97a9ae281db8cedaae10cd4beab3d97adc4fae 100644 (file)
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -159,7 +159,7 @@
 #vacuum_cost_page_hit = 1              # 0-10000 credits
 #vacuum_cost_page_miss = 10            # 0-10000 credits
 #vacuum_cost_page_dirty = 20           # 0-10000 credits
-#vacuum_cost_limit = 2000              # 1-10000 credits
+#vacuum_cost_limit = 200               # 1-10000 credits
 
 # - Background Writer -