From: Nathan Bossart <nathan@postgresql.org>
Date: Fri, 20 Feb 2026 18:07:27 +0000 (-0600)
Subject: Speedup COPY FROM with additional function inlining.
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=dc592a41557b072178f1798700bf9c69cd8e4235;p=thirdparty%2Fpostgresql.git

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
inlining CopyReadLineText() and passing the is_csv parameter as a
constant.  This allows the compiler to emit specialized code with
fewer branches.

This is preparatory work for a proposed follow-up commit that would
further optimize this code with SIMD instructions.

Author: Nazir Bilal Yavuz <byavuz81@gmail.com>
Reviewed-by: Ayoub Kazar <ma_kazar@esi.dz>
Tested-by: Manni Wood <manni.wood@enterprisedb.com>
Discussion: https://postgr.es/m/CAOzEurSW8cNr6TPKsjrstnPfhf4QyQqB4tnPXGGe8N4e_v7Jig%40mail.gmail.com
---

diff --git a/src/backend/commands/copyfromparse.c b/src/backend/commands/copyfromparse.c
index 94d6f415a06..6b00d49c50f 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 +1174,17 @@ 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 fewer branches.
+	 */
+	if (is_csv)
+		result = CopyReadLineText(cstate, true);
+	else
+		result = CopyReadLineText(cstate, false);
 
 	if (result)
 	{
@@ -1241,7 +1251,7 @@ 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;