Remove some unnecessary tests of pgstat_track_counts.

tglsfdc · tglsfdc · commit f4d242ef9473 · 2010-10-12T14:44:25.000-04:00
We may as well make pgstat_count_heap_scan() and related macros just count
whenever rel-&gt;pgstat_info isn't null.  Testing pgstat_track_counts buys
nothing at all in the normal case where that flag is ON; and when it's OFF,
the pgstat_info link will be null, so it's still a useless test.

This change is unlikely to buy any noticeable performance improvement,
but a cycle shaved is a cycle earned; and my investigations earlier today
convinced me that we're down to the point where individual instructions in
the inner execution loops are starting to matter.
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
@@ -1660,7 +1660,7 @@ pgstat_count_heap_insert(Relation rel)
 {
 	PgStat_TableStatus *pgstat_info = rel->pgstat_info;
 
-	if (pgstat_track_counts && pgstat_info != NULL)
+	if (pgstat_info != NULL)
 	{
 		/* We have to log the effect at the proper transactional level */
 		int			nest_level = GetCurrentTransactionNestLevel();
@@ -1681,7 +1681,7 @@ pgstat_count_heap_update(Relation rel, bool hot)
 {
 	PgStat_TableStatus *pgstat_info = rel->pgstat_info;
 
-	if (pgstat_track_counts && pgstat_info != NULL)
+	if (pgstat_info != NULL)
 	{
 		/* We have to log the effect at the proper transactional level */
 		int			nest_level = GetCurrentTransactionNestLevel();
@@ -1706,7 +1706,7 @@ pgstat_count_heap_delete(Relation rel)
 {
 	PgStat_TableStatus *pgstat_info = rel->pgstat_info;
 
-	if (pgstat_track_counts && pgstat_info != NULL)
+	if (pgstat_info != NULL)
 	{
 		/* We have to log the effect at the proper transactional level */
 		int			nest_level = GetCurrentTransactionNestLevel();
@@ -1732,7 +1732,7 @@ pgstat_update_heap_dead_tuples(Relation rel, int delta)
 {
 	PgStat_TableStatus *pgstat_info = rel->pgstat_info;
 
-	if (pgstat_track_counts && pgstat_info != NULL)
+	if (pgstat_info != NULL)
 		pgstat_info->t_counts.t_delta_dead_tuples -= delta;
 }
 
diff --git a/src/include/pgstat.h b/src/include/pgstat.h
@@ -705,37 +705,37 @@ extern void pgstat_initstats(Relation rel);
 
 #define pgstat_count_heap_scan(rel)									\
 	do {															\
-		if (pgstat_track_counts && (rel)->pgstat_info != NULL)		\
+		if ((rel)->pgstat_info != NULL)								\
 			(rel)->pgstat_info->t_counts.t_numscans++;				\
 	} while (0)
 #define pgstat_count_heap_getnext(rel)								\
 	do {															\
-		if (pgstat_track_counts && (rel)->pgstat_info != NULL)		\
+		if ((rel)->pgstat_info != NULL)								\
 			(rel)->pgstat_info->t_counts.t_tuples_returned++;		\
 	} while (0)
 #define pgstat_count_heap_fetch(rel)								\
 	do {															\
-		if (pgstat_track_counts && (rel)->pgstat_info != NULL)		\
+		if ((rel)->pgstat_info != NULL)								\
 			(rel)->pgstat_info->t_counts.t_tuples_fetched++;		\
 	} while (0)
 #define pgstat_count_index_scan(rel)								\
 	do {															\
-		if (pgstat_track_counts && (rel)->pgstat_info != NULL)		\
+		if ((rel)->pgstat_info != NULL)								\
 			(rel)->pgstat_info->t_counts.t_numscans++;				\
 	} while (0)
 #define pgstat_count_index_tuples(rel, n)							\
 	do {															\
-		if (pgstat_track_counts && (rel)->pgstat_info != NULL)		\
+		if ((rel)->pgstat_info != NULL)								\
 			(rel)->pgstat_info->t_counts.t_tuples_returned += (n);	\
 	} while (0)
 #define pgstat_count_buffer_read(rel)								\
 	do {															\
-		if (pgstat_track_counts && (rel)->pgstat_info != NULL)		\
+		if ((rel)->pgstat_info != NULL)								\
 			(rel)->pgstat_info->t_counts.t_blocks_fetched++;		\
 	} while (0)
 #define pgstat_count_buffer_hit(rel)								\
 	do {															\
-		if (pgstat_track_counts && (rel)->pgstat_info != NULL)		\
+		if ((rel)->pgstat_info != NULL)								\
 			(rel)->pgstat_info->t_counts.t_blocks_hit++;			\
 	} while (0)
 

Original file line number	Diff line number	Diff line change
`@@ -1660,7 +1660,7 @@ pgstat_count_heap_insert(Relation rel)`
`1660`	`1660`	`{`
`1661`	`1661`	`PgStat_TableStatus *pgstat_info = rel->pgstat_info;`
`1662`	`1662`
`1663`		`- if (pgstat_track_counts && pgstat_info != NULL)`
	`1663`	`+ if (pgstat_info != NULL)`
`1664`	`1664`	`{`
`1665`	`1665`	`/* We have to log the effect at the proper transactional level */`
`1666`	`1666`	`int nest_level = GetCurrentTransactionNestLevel();`
`@@ -1681,7 +1681,7 @@ pgstat_count_heap_update(Relation rel, bool hot)`
`1681`	`1681`	`{`
`1682`	`1682`	`PgStat_TableStatus *pgstat_info = rel->pgstat_info;`
`1683`	`1683`
`1684`		`- if (pgstat_track_counts && pgstat_info != NULL)`
	`1684`	`+ if (pgstat_info != NULL)`
`1685`	`1685`	`{`
`1686`	`1686`	`/* We have to log the effect at the proper transactional level */`
`1687`	`1687`	`int nest_level = GetCurrentTransactionNestLevel();`
`@@ -1706,7 +1706,7 @@ pgstat_count_heap_delete(Relation rel)`
`1706`	`1706`	`{`
`1707`	`1707`	`PgStat_TableStatus *pgstat_info = rel->pgstat_info;`
`1708`	`1708`
`1709`		`- if (pgstat_track_counts && pgstat_info != NULL)`
	`1709`	`+ if (pgstat_info != NULL)`
`1710`	`1710`	`{`
`1711`	`1711`	`/* We have to log the effect at the proper transactional level */`
`1712`	`1712`	`int nest_level = GetCurrentTransactionNestLevel();`
`@@ -1732,7 +1732,7 @@ pgstat_update_heap_dead_tuples(Relation rel, int delta)`
`1732`	`1732`	`{`
`1733`	`1733`	`PgStat_TableStatus *pgstat_info = rel->pgstat_info;`
`1734`	`1734`
`1735`		`- if (pgstat_track_counts && pgstat_info != NULL)`
	`1735`	`+ if (pgstat_info != NULL)`
`1736`	`1736`	`pgstat_info->t_counts.t_delta_dead_tuples -= delta;`
`1737`	`1737`	`}`
`1738`	`1738`