Scan the buffer pool just once, not once per fork, during relation drop.

This provides a speedup of about 4X when NBuffers is large enough.
There is also a useful reduction in sinval traffic, since we
only do CacheInvalidateSmgr() once not once per fork.

Simon Riggs, reviewed and somewhat revised by Tom Lane

2 files changed, 3 insertions, 11 deletions

diff --git a/src/backend/access/transam/twophase.c b/src/backend/access/transam/twophase.c
index 6db46c00109..0b41a76a325 100644
--- a/src/backend/access/transam/twophase.c
+++ b/src/backend/access/transam/twophase.c
@@ -1356,12 +1356,8 @@ FinishPreparedTransaction(const char *gid, bool isCommit)
 	for (i = 0; i < ndelrels; i++)
 	{
 		SMgrRelation srel = smgropen(delrels[i], InvalidBackendId);
-		ForkNumber	fork;
 
-		for (fork = 0; fork <= MAX_FORKNUM; fork++)
-		{
-			smgrdounlink(srel, fork, false);
-		}
+		smgrdounlink(srel, false);
 		smgrclose(srel);
 	}
 
diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 49c14cb64c0..659b53524cd 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -4638,10 +4638,8 @@ xact_redo_commit_internal(TransactionId xid, XLogRecPtr lsn,
 		ForkNumber	fork;
 
 		for (fork = 0; fork <= MAX_FORKNUM; fork++)
-		{
 			XLogDropRelation(xnodes[i], fork);
-			smgrdounlink(srel, fork, true);
-		}
+		smgrdounlink(srel, true);
 		smgrclose(srel);
 	}
 
@@ -4778,10 +4776,8 @@ xact_redo_abort(xl_xact_abort *xlrec, TransactionId xid)
 		ForkNumber	fork;
 
 		for (fork = 0; fork <= MAX_FORKNUM; fork++)
-		{
 			XLogDropRelation(xlrec->xnodes[i], fork);
-			smgrdounlink(srel, fork, true);
-		}
+		smgrdounlink(srel, true);
 		smgrclose(srel);
 	}
 }