Use pgBufferUsage for buffer usage tracking in analyze.

Previously, (auto)analyze used global variables VacuumPageHit,
VacuumPageMiss, and VacuumPageDirty to track buffer usage. However,
pgBufferUsage provides a more generic way to track buffer usage with
support functions.

This change replaces those global variables with pgBufferUsage in
analyze. Since analyze was the sole user of those variables, it
removes their declarations. Vacuum previously used those variables but
replaced them with pgBufferUsage as part of a bug fix, commit
5cd72cc0c.

Additionally, it adjusts the buffer usage message in both vacuum and
analyze for better consistency.

Author: Anthonin Bonnefoy
Reviewed-by: Masahiko Sawada, Michael Paquier
Discussion: https://postgr.es/m/CAO6_Xqr__kTTCLkftqS0qSCm-J7_xbRG3Ge2rWhucxQJMJhcRA%40mail.gmail.com

1 files changed, 22 insertions, 19 deletions

diff --git a/src/backend/commands/analyze.c b/src/backend/commands/analyze.c
index c590a2adc35..50159232218 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;
 
@@ -736,15 +735,19 @@ do_analyze_rel(Relation onerel, VacuumParams *params,
 			double		read_rate = 0;
 			double		write_rate = 0;
 			StringInfoData buf;
+			int64		total_blks_hit;
+			int64		total_blks_read;
+			int64		total_blks_dirtied;
 
-			/*
-			 * Calculate the difference in the Page Hit/Miss/Dirty that
-			 * 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);
+
+			total_blks_hit = bufferusage.shared_blks_hit +
+				bufferusage.local_blks_hit;
+			total_blks_read = bufferusage.shared_blks_read +
+				bufferusage.local_blks_read;
+			total_blks_dirtied = bufferusage.shared_blks_dirtied +
+				bufferusage.local_blks_dirtied;
 
 			/*
 			 * We do not expect an analyze to take > 25 days and it simplifies
@@ -770,10 +773,10 @@ 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 * total_blks_read /
+					(1024 * 1024) / (delay_in_ms / 1000.0);
+				write_rate = (double) BLCKSZ * total_blks_dirtied /
+					(1024 * 1024) / (delay_in_ms / 1000.0);
 			}
 
 			/*
@@ -796,10 +799,10 @@ 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);
+			appendStringInfo(&buf, _("buffer usage: %lld hits, %lld reads, %lld dirtied\n"),
+							 (long long) total_blks_hit,
+							 (long long) total_blks_read,
+							 (long long) total_blks_dirtied);
 			appendStringInfo(&buf, _("system usage: %s"), pg_rusage_show(&ru0));
 
 			ereport(LOG,