Date: Wed, 18 Feb 2026 15:26:14 -0600
From: Nathan Bossart <nathandbossart@gmail.com>
To: Nazir Bilal Yavuz <byavuz81@gmail.com>
Cc: KAZAR Ayoub <ma_kazar@esi.dz>, Neil Conway <neil.conway@gmail.com>,
	Manni Wood <manni.wood@enterprisedb.com>,
	Andrew Dunstan <andrew@dunslane.net>,
	Shinya Kato <shinya11.kato@gmail.com>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: Speed up COPY FROM text/CSV parsing using SIMD
Message-ID: <aZYudtuBLVb36pZE@nathan>
References: <CAN55FZ0FRB2OD6-oEESLvgUT4bLZQVD72pAqUqzdw7Rx5cN0ig@mail.gmail.com>
 <CA+K2Run1VdLnmp-5_Qv2Fax0KgT7LLJMH-uzjaaf-NZD1oU-=w@mail.gmail.com>
 <aYZdKSTw6N3khsVE@nathan>
 <CAN55FZ2DOeLjSXE2Jos99bgHG-Zeo3KjStrSgoA8Rf=2Mu+hFA@mail.gmail.com>
 <aYZvdsXPElQvwWOA@nathan>
 <CAN55FZ1=O6TjeZM2CUT7T2tu66uJT+w3G9FiRXVs+gt_ousFxQ@mail.gmail.com>
 <aY0FL4rXUl6ykn-a@nathan>
 <CAN55FZ3g6QaiC8G4GMjdJ24egvgc-HG_xpoOztxnM_wnQNn5aw@mail.gmail.com>
 <aY-vJe_ENCB-fux9@nathan>
 <CAN55FZ2OpqRxUUEvgPpHCk2HnY0xZSH1x09fgFGOUyXSv8HcEA@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="qJ6V/+kxsNWNoiKe"
Content-Disposition: inline
In-Reply-To: <CAN55FZ2OpqRxUUEvgPpHCk2HnY0xZSH1x09fgFGOUyXSv8HcEA@mail.gmail.com>
Archived-At: <https://www.postgresql.org/message-id/aZYudtuBLVb36pZE%40nathan>
Precedence: bulk


--qJ6V/+kxsNWNoiKe
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Wed, Feb 18, 2026 at 04:38:07PM +0300, Nazir Bilal Yavuz wrote:
> By looking at these results having both is_csv and simd_enabled as an
> argument and sending them as constant boolean arguments help most.

Thanks for doing these tests.  ISTM we might as well get this initial
inlining stuff committed.  Thoughts?

-- 
nathan

--qJ6V/+kxsNWNoiKe
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v8-0001-Speedup-COPY-FROM-with-additional-function-inlini.patch

From 516176894a682e8bd4cb32202e3726f6621ba44d Mon Sep 17 00:00:00 2001
From: Nathan Bossart <nathan@postgresql.org>
Date: Wed, 18 Feb 2026 14:55:39 -0600
Subject: [PATCH v8 1/1] Speedup COPY FROM with additional function inlining.

Following the example set by commit 58a359e585, we can squeeze out
a little more performance from COPY FROM (FORMAT {text,csv}) by
forcing CopyReadLineText() to be inlined and by passing the is_csv
parameter as a constant.  This allows the compiler to emit
specialized code with the known-const false comparisons and
subsequent branches removed.

Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Ayoub Kazar <ma_kazar@esi.dz>
Discussion: https://postgr.es/m/CAOzEurSW8cNr6TPKsjrstnPfhf4QyQqB4tnPXGGe8N4e_v7Jig%40mail.gmail.com
---
 src/backend/commands/copyfromparse.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 94d6f415a06..0aa549837b5 100644
--- a/src/backend/commands/copyfromparse.c
+++ b/src/backend/commands/copyfromparse.c
@@ -141,7 +141,8 @@ static const char BinarySignature[11] = "PGCOPY\n\377\r\n\0";
 
 /* non-export function prototypes */
 static bool CopyReadLine(CopyFromState cstate, bool is_csv);
-static bool CopyReadLineText(CopyFromState cstate, bool is_csv);
+static pg_attribute_always_inline bool CopyReadLineText(CopyFromState cstate,
+														bool is_csv);
 static int	CopyReadAttributesText(CopyFromState cstate);
 static int	CopyReadAttributesCSV(CopyFromState cstate);
 static Datum CopyReadBinaryAttribute(CopyFromState cstate, FmgrInfo *flinfo,
@@ -1173,8 +1174,18 @@ CopyReadLine(CopyFromState cstate, bool is_csv)
 	resetStringInfo(&cstate->line_buf);
 	cstate->line_buf_valid = false;
 
-	/* Parse data and transfer into line_buf */
-	result = CopyReadLineText(cstate, is_csv);
+	/*
+	 * Parse data and transfer into line_buf.
+	 *
+	 * Because this is performance critical, we inline CopyReadLineText() and
+	 * pass the boolean parameters as constants to allow the compiler to emit
+	 * specialized code with the known-const false comparisons and subsequent
+	 * branches removed.
+	 */
+	if (is_csv)
+		result = CopyReadLineText(cstate, true);
+	else
+		result = CopyReadLineText(cstate, false);
 
 	if (result)
 	{
@@ -1241,7 +1252,7 @@ CopyReadLine(CopyFromState cstate, bool is_csv)
 /*
  * CopyReadLineText - inner loop of CopyReadLine for text mode
  */
-static bool
+static pg_attribute_always_inline bool
 CopyReadLineText(CopyFromState cstate, bool is_csv)
 {
 	char	   *copy_input_buf;
-- 
2.50.1 (Apple Git-155)


--qJ6V/+kxsNWNoiKe--