GUC table: Add description to computed variables

Per suggestion from Kyotaro Horiguchi
Discussion: https://postgr.es/m/20240229.130404.1411153273308142188.horikyota.ntt@gmail.com

diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 93ded31ed9205e057e38fd2d435bfe31b9fef963..543a87c659699d555b7abb5b97393d500ce4f605 100644 (file)
--- a/src/backend/utils/misc/guc_tables.c
+++ b/src/backend/utils/misc/guc_tables.c
@@ -2287,7 +2287,7 @@ struct config_int ConfigureNamesInt[] =
        {
                {"commit_timestamp_buffers", PGC_POSTMASTER, RESOURCES_MEM,
                        gettext_noop("Sets the size of the dedicated buffer pool used for the commit timestamp cache."),
-                       NULL,
+                       gettext_noop("Specify 0 to have this value determined as a fraction of shared_buffers."),
                        GUC_UNIT_BLOCKS
                },
                &commit_timestamp_buffers,
@@ -2342,7 +2342,7 @@ struct config_int ConfigureNamesInt[] =
        {
                {"subtransaction_buffers", PGC_POSTMASTER, RESOURCES_MEM,
                        gettext_noop("Sets the size of the dedicated buffer pool used for the sub-transaction cache."),
-                       NULL,
+                       gettext_noop("Specify 0 to have this value determined as a fraction of shared_buffers."),
                        GUC_UNIT_BLOCKS
                },
                &subtransaction_buffers,
@@ -2353,7 +2353,7 @@ struct config_int ConfigureNamesInt[] =
        {
                {"transaction_buffers", PGC_POSTMASTER, RESOURCES_MEM,
                        gettext_noop("Sets the size of the dedicated buffer pool used for the transaction status cache."),
-                       NULL,
+                       gettext_noop("Specify 0 to have this value determined as a fraction of shared_buffers."),
                        GUC_UNIT_BLOCKS
                },
                &transaction_buffers,
@@ -2868,7 +2868,7 @@ struct config_int ConfigureNamesInt[] =
        {
                {"wal_buffers", PGC_POSTMASTER, WAL_SETTINGS,
                        gettext_noop("Sets the number of disk-page buffers in shared memory for WAL."),
-                       NULL,
+                       gettext_noop("Specify -1 to have this value determined as a fraction of shared_buffers."),
                        GUC_UNIT_XBLOCKS
                },
                &XLOGbuffers,