v4-0002-Use-pgBufferUsage-for-analyze-block-reporting.patch

From 7848314c423376fc7d4403b5b9d41bc49e8ba5e5 Mon Sep 17 00:00:00 2001
From: Anthonin Bonnefoy <anthonin.bonnefoy@datadoghq.com>
Date: Wed, 24 Apr 2024 10:40:33 +0200
Subject: Use pgBufferUsage for analyze block reporting

pgBufferUsage is already tracking block usage, making
VacuumPage{Hit,Miss,Dirty} redundant. Replace Vacuum specific variables
by pgBufferUsage
---
 src/backend/commands/analyze.c | 24 +++++++++++-------------
 1 file changed, 11 insertions(+), 13 deletions(-)

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index 7d2cd24997..cab5792525 100644
--- a/src/backend/commands/analyze.c
+++ b/src/backend/commands/analyze.c
@@ -303,9 +303,8 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
 	Oid			save_userid;
 	int			save_sec_context;
 	int			save_nestlevel;
-	int64		AnalyzePageHit = VacuumPageHit;
-	int64		AnalyzePageMiss = VacuumPageMiss;
-	int64		AnalyzePageDirty = VacuumPageDirty;
+	BufferUsage startbufferusage = pgBufferUsage;
+	BufferUsage bufferusage;
 	PgStat_Counter startreadtime = 0;
 	PgStat_Counter startwritetime = 0;
 
@@ -737,9 +736,8 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
 			 * happened as part of the analyze by subtracting out the
 			 * pre-analyze values which we saved above.
 			 */
-			AnalyzePageHit = VacuumPageHit - AnalyzePageHit;
-			AnalyzePageMiss = VacuumPageMiss - AnalyzePageMiss;
-			AnalyzePageDirty = VacuumPageDirty - AnalyzePageDirty;
+			memset(&bufferusage, 0, sizeof(BufferUsage));
+			BufferUsageAccumDiff(&bufferusage, &pgBufferUsage, &startbufferusage);
 
 			/*
 			 * We do not expect an analyze to take > 25 days and it simplifies
@@ -765,10 +763,10 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
 
 			if (delay_in_ms > 0)
 			{
-				read_rate = (double) BLCKSZ * AnalyzePageMiss / (1024 * 1024) /
-					(delay_in_ms / 1000.0);
-				write_rate = (double) BLCKSZ * AnalyzePageDirty / (1024 * 1024) /
-					(delay_in_ms / 1000.0);
+				read_rate = (double) BLCKSZ * (bufferusage.shared_blks_read + bufferusage.local_blks_read) /
+					(1024 * 1024) / (delay_in_ms / 1000.0);
+				write_rate = (double) BLCKSZ * (bufferusage.shared_blks_dirtied + bufferusage.local_blks_dirtied) /
+					(1024 * 1024) / (delay_in_ms / 1000.0);
 			}
 
 			/*
@@ -792,9 +790,9 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
 			appendStringInfo(&buf, _("avg read rate: %.3f MB/s, avg write rate: %.3f MB/s\n"),
 							 read_rate, write_rate);
 			appendStringInfo(&buf, _("buffer usage: %lld hits, %lld misses, %lld dirtied\n"),
-							 (long long) AnalyzePageHit,
-							 (long long) AnalyzePageMiss,
-							 (long long) AnalyzePageDirty);
+							 (long long) (bufferusage.shared_blks_hit + bufferusage.local_blks_hit),
+							 (long long) (bufferusage.shared_blks_read + bufferusage.local_blks_read),
+							 (long long) (bufferusage.shared_blks_dirtied + bufferusage.local_blks_dirtied));
 			appendStringInfo(&buf, _("system usage: %s"), pg_rusage_show(&ru0));
 
 			ereport(LOG,
-- 
2.39.3 (Apple Git-146)