Add num_done counter to the pg_stat_checkpointer view.

Checkpoints can be skipped when the server is idle. The existing num_timed and
num_requested counters in pg_stat_checkpointer track both completed and
skipped checkpoints, but there was no way to count only the completed ones.

This commit introduces the num_done counter, which tracks only completed
checkpoints, making it easier to see how many were actually performed.

Bump catalog version.

Author: Anton A. Melnikov
Reviewed-by: Fujii Masao
Discussion: https://postgr.es/m/9ea77f40-818d-4841-9dee-158ac8f6e690@oss.nttdata.com

4 files changed, 8 insertions, 2 deletions

diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h
index 083810f5b4c..36f6e4e4b4e 100644
--- a/src/include/access/xlog.h
+++ b/src/include/access/xlog.h
@@ -239,7 +239,7 @@ extern void LocalProcessControlFile(bool reset);
 extern WalLevel GetActiveWalLevelOnStandby(void);
 extern void StartupXLOG(void);
 extern void ShutdownXLOG(int code, Datum arg);
-extern void CreateCheckPoint(int flags);
+extern bool CreateCheckPoint(int flags);
 extern bool CreateRestartPoint(int flags);
 extern WALAvailability GetWALAvailability(XLogRecPtr targetLSN);
 extern void XLogPutNextOid(Oid nextOid);
diff --git a/src/include/catalog/catversion.h b/src/include/catalog/catversion.h
index ba4f8641ac6..7656714b701 100644
--- a/src/include/catalog/catversion.h
+++ b/src/include/catalog/catversion.h
@@ -57,6 +57,6 @@
  */
 
 /*							yyyymmddN */
-#define CATALOG_VERSION_NO	202409271
+#define CATALOG_VERSION_NO	202409301
 
 #endif
diff --git a/src/include/catalog/pg_proc.dat b/src/include/catalog/pg_proc.dat
index 322114d72a7..05fcbf75156 100644
--- a/src/include/catalog/pg_proc.dat
+++ b/src/include/catalog/pg_proc.dat
@@ -5820,6 +5820,11 @@
   proname => 'pg_stat_get_checkpointer_num_requested', provolatile => 's',
   proparallel => 'r', prorettype => 'int8', proargtypes => '',
   prosrc => 'pg_stat_get_checkpointer_num_requested' },
+{ oid => '8599',
+  descr => 'statistics: number of checkpoints performed by the checkpointer',
+  proname => 'pg_stat_get_checkpointer_num_performed', provolatile => 's',
+  proparallel => 'r', prorettype => 'int8', proargtypes => '',
+  prosrc => 'pg_stat_get_checkpointer_num_performed' },
 { oid => '6327',
   descr => 'statistics: number of timed restartpoints started by the checkpointer',
   proname => 'pg_stat_get_checkpointer_restartpoints_timed', provolatile => 's',
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
index 4752dfe7197..476acd680c0 100644
--- a/src/include/pgstat.h
+++ b/src/include/pgstat.h
@@ -294,6 +294,7 @@ typedef struct PgStat_CheckpointerStats
 {
 	PgStat_Counter num_timed;
 	PgStat_Counter num_requested;
+	PgStat_Counter num_performed;
 	PgStat_Counter restartpoints_timed;
 	PgStat_Counter restartpoints_requested;
 	PgStat_Counter restartpoints_performed;