Feedback-ID: ia2694551:Fastmail
Date: Thu, 29 Feb 2024 11:46:42 +0100
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Cc: x4mmm@yandex-team.ru, dilipbalaut@gmail.com, tndrwang@gmail.com, 
	pgsql-hackers@lists.postgresql.org, tomas.vondra@enterprisedb.com
Subject: Re: SLRU optimization - configurable buffer pool and partitioning
 the SLRU lock
Message-ID: <202402291046.xpykltdowf22@alvherre.pgsql>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="3e552o3yj4zghlrd"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: <20240229.130404.1411153273308142188.horikyota.ntt@gmail.com>
Archived-At: <https://www.postgresql.org/message-id/202402291046.xpykltdowf22%40alvherre.pgsql>
Precedence: bulk


--3e552o3yj4zghlrd
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit

On 2024-Feb-29, Kyotaro Horiguchi wrote:

> At Tue, 27 Feb 2024 18:33:18 +0100, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote in 
> > Here's the complete set, with these two names using the singular.
> 
> The commit by the second patch added several GUC descriptions:
> 
> > Sets the size of the dedicated buffer pool used for the commit timestamp cache.
> 
> Some of them, commit_timestamp_buffers, transaction_buffers,
> subtransaction_buffers use 0 to mean auto-tuning based on
> shared-buffer size. I think it's worth adding an extra_desc such as "0
> to automatically determine this value based on the shared buffer
> size".

How about this?

-- 
Álvaro Herrera        Breisgau, Deutschland  —  https://www.EnterpriseDB.com/
"La victoria es para quien se atreve a estar solo"

--3e552o3yj4zghlrd
Content-Type: text/x-diff; charset=utf-8
Content-Disposition: attachment; filename="0001-extra_desc.patch"

From d0d7216eb4e2e2e9e71aa849cf90c218bbe2b164 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 29 Feb 2024 11:45:31 +0100
Subject: [PATCH] extra_desc

---
 src/backend/utils/misc/guc_tables.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/backend/utils/misc/guc_tables.c b/src/backend/utils/misc/guc_tables.c
index 93ded31ed9..543a87c659 100644
--- 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,
-- 
2.39.2


--3e552o3yj4zghlrd--