Thread

[PATCH v1 08/12] prune_xid-hist: collect data from heap_{delete,update,insert}

Renan Alves Fonseca <renanfonseca@gmail.com> — 2025-05-20T11:43:23Z

---
 src/backend/access/heap/heapam.c | 22 ++++++++++++++++++----
 src/include/storage/bufpage.h    | 12 ++++++++++++
 2 files changed, 30 insertions(+), 4 deletions(-)

diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index c1a4de14a59..08a3ecfcdbb 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2748,6 +2748,8 @@ heap_delete(Relation relation, ItemPointer tid,
 {
 	TM_Result	result;
 	TransactionId xid = GetCurrentTransactionId();
+	TransactionId old_prune_xid;
+	bool		prune_xid_changed = false;
 	ItemId		lp;
 	HeapTupleData tp;
 	Page		page;
@@ -3015,7 +3017,7 @@ l1:
 	 * the subsequent page pruning will be a no-op and the hint will be
 	 * cleared.
 	 */
-	PageSetPrunable(page, xid);
+	PageSetPrunableReporting(page, xid, old_prune_xid, prune_xid_changed);
 
 	if (PageIsAllVisible(page))
 	{
@@ -3148,6 +3150,9 @@ l1:
 
 	pgstat_count_heap_delete(relation);
 
+	if (prune_xid_changed)
+		pgstat_update_relation_prune_xid_histogram(relation, old_prune_xid, xid);
+
 	if (old_key_tuple != NULL && old_key_copied)
 		heap_freetuple(old_key_tuple);
 
@@ -3216,6 +3221,8 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 {
 	TM_Result	result;
 	TransactionId xid = GetCurrentTransactionId();
+	TransactionId old_prune_xid;
+	bool		prune_xid_changed = false;
 	Bitmapset  *hot_attrs;
 	Bitmapset  *sum_attrs;
 	Bitmapset  *key_attrs;
@@ -4029,7 +4036,7 @@ l2:
 	 * not to optimize for aborts.  Note that heap_xlog_update must be kept in
 	 * sync if this decision changes.
 	 */
-	PageSetPrunable(page, xid);
+	PageSetPrunableReporting(page, xid, old_prune_xid, prune_xid_changed);
 
 	if (use_hot_update)
 	{
@@ -4144,6 +4151,9 @@ l2:
 
 	pgstat_count_heap_update(relation, use_hot_update, newbuf != buffer);
 
+	if (prune_xid_changed)
+		pgstat_update_relation_prune_xid_histogram(relation, old_prune_xid, xid);
+
 	/*
 	 * If heaptup is a private copy, release it.  Don't forget to copy t_self
 	 * back to the caller's image, too.
@@ -6139,6 +6149,9 @@ void
 heap_abort_speculative(Relation relation, ItemPointer tid)
 {
 	TransactionId xid = GetCurrentTransactionId();
+	TransactionId prune_xid;
+	TransactionId old_prune_xid;
+	bool		prune_xid_changed = false;
 	ItemId		lp;
 	HeapTupleData tp;
 	Page		page;
@@ -6198,13 +6211,12 @@ heap_abort_speculative(Relation relation, ItemPointer tid)
 	Assert(TransactionIdIsValid(TransactionXmin));
 	{
 		TransactionId relfrozenxid = relation->rd_rel->relfrozenxid;
-		TransactionId prune_xid;
 
 		if (TransactionIdPrecedes(TransactionXmin, relfrozenxid))
 			prune_xid = relfrozenxid;
 		else
 			prune_xid = TransactionXmin;
-		PageSetPrunable(page, prune_xid);
+		PageSetPrunableReporting(page, prune_xid, old_prune_xid, prune_xid_changed);
 	}
 
 	/* store transaction information of xact deleting the tuple */
@@ -6271,6 +6283,8 @@ heap_abort_speculative(Relation relation, ItemPointer tid)
 
 	/* count deletion, as we counted the insertion too */
 	pgstat_count_heap_delete(relation);
+	if (prune_xid_changed)
+		pgstat_update_relation_prune_xid_histogram(relation, old_prune_xid, prune_xid);
 }
 
 /*
diff --git a/src/include/storage/bufpage.h b/src/include/storage/bufpage.h
index aeb67c498c5..8a0774dc271 100644
--- a/src/include/storage/bufpage.h
+++ b/src/include/storage/bufpage.h
@@ -452,6 +452,18 @@ do { \
 		TransactionIdPrecedes(xid, ((PageHeader) (page))->pd_prune_xid)) \
 		((PageHeader) (page))->pd_prune_xid = (xid); \
 } while (0)
+#define PageSetPrunableReporting(page, xid, old_xid, changed)	\
+do { \
+	Assert(TransactionIdIsNormal(xid)); \
+	if (!TransactionIdIsValid(((PageHeader) (page))->pd_prune_xid) || \
+		TransactionIdPrecedes(xid, ((PageHeader) (page))->pd_prune_xid)) \
+	    { \
+            old_xid = ((PageHeader) (page))->pd_prune_xid; \
+            ((PageHeader) (page))->pd_prune_xid = (xid); \
+		    changed = true; \
+        } \
+} while (0)
+
 #define PageClearPrunable(page) \
 	(((PageHeader) (page))->pd_prune_xid = InvalidTransactionId)
 
-- 
2.47.0


--=-=-=
Content-Type: text/x-patch
Content-Disposition: attachment;
 filename=v1-0009-prune_xid-hist-collect-data-from-opportunistic-pr.patch