Improve defaults shown in postgresql.conf.sample and pg_settings

Previously, these showed unlikely default values.  The new default value
128MB (since PG 10) is not always accurate since initdb tries several
increasing values, but it likely to be accurate.

Reported-by: Zhangjie <zhangjie2@fujitsu.com>
Discussion: https://postgr.es/m/TYWPR01MB7678772FD8640C404F1DC882F9079@TYWPR01MB7678.jpnprd01.prod.outlook.com

Author: Zhangjie

Backpatch-through: master

diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c
index a2e0f8de7e740f120b5f205d4d87299ba854b39f..467b0fd6fe79a6847bc5a5ba2219bdffce359fa6 100644 (file)
--- a/src/backend/utils/misc/guc.c
+++ b/src/backend/utils/misc/guc.c
@@ -2333,7 +2333,7 @@ static struct config_int ConfigureNamesInt[] =
                        GUC_UNIT_BLOCKS
                },
                &NBuffers,
-               1024, 16, INT_MAX / 2,
+               16384, 16, INT_MAX / 2,
                NULL, NULL, NULL
        },
 

diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample
index b242a7fc8b370a7a0fbdc0db681be79053a8040c..3fe9a53cb3fdeed1763fe0822ca0ca9de1846084 100644 (file)
--- a/src/backend/utils/misc/postgresql.conf.sample
+++ b/src/backend/utils/misc/postgresql.conf.sample
@@ -124,7 +124,7 @@
 
 # - Memory -
 
-#shared_buffers = 32MB                 # min 128kB
+#shared_buffers = 128MB                        # min 128kB
                                        # (change requires restart)
 #huge_pages = try                      # on, off, or try
                                        # (change requires restart)

diff --git a/src/bin/initdb/initdb.c b/src/bin/initdb/initdb.c
index f05cddf0e088b0719d90db53cc15605095bc9bbb..a16ad026f32da93a0c22f93cef3d2f589d7dfb7f 100644 (file)
--- a/src/bin/initdb/initdb.c
+++ b/src/bin/initdb/initdb.c
@@ -1071,7 +1071,7 @@ setup_config(void)
        else
                snprintf(repltok, sizeof(repltok), "shared_buffers = %dkB",
                                 n_buffers * (BLCKSZ / 1024));
-       conflines = replace_token(conflines, "#shared_buffers = 32MB", repltok);
+       conflines = replace_token(conflines, "#shared_buffers = 128MB", repltok);
 
 #ifdef HAVE_UNIX_SOCKETS
        snprintf(repltok, sizeof(repltok), "#unix_socket_directories = '%s'",