Hello
Pavan Deolasee recently noted that a few of the
HeapTupleHeaderIndicatesMovedPartitions calls added by commit
5db6df0c0117 are useless, since they are done after comparing t_self
with t_ctid. That's because t_self can never be set to the magical
values that indicate that the tuple moved partition. If the first
test fails (so we know t_self equals t_ctid), necessarily the second
test will also fail.
So these checks can be removed and no harm is done.
--
Álvaro Herrera 39°49'30"S 73°17'W
>From 953eceb701ca35c5a3c731c4318ed1465f205811 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvhe...@alvh.no-ip.org>
Date: Tue, 29 Sep 2020 10:47:45 -0300
Subject: [PATCH] Remove pointless HeapTupleHeaderIndicatesMovedPartitions
calls
---
src/backend/access/heap/heapam.c | 12 ++++--------
src/backend/access/heap/heapam_visibility.c | 9 +++------
2 files changed, 7 insertions(+), 14 deletions(-)
diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c
index 1585861a02..868ff13453 100644
--- a/src/backend/access/heap/heapam.c
+++ b/src/backend/access/heap/heapam.c
@@ -2618,8 +2618,7 @@ l1:
HEAP_XMAX_IS_LOCKED_ONLY(tp.t_data->t_infomask) ||
HeapTupleHeaderIsOnlyLocked(tp.t_data))
result = TM_Ok;
- else if (!ItemPointerEquals(&tp.t_self, &tp.t_data->t_ctid) ||
- HeapTupleHeaderIndicatesMovedPartitions(tp.t_data))
+ else if (!ItemPointerEquals(&tp.t_self, &tp.t_data->t_ctid))
result = TM_Updated;
else
result = TM_Deleted;
@@ -3248,8 +3247,7 @@ l2:
if (can_continue)
result = TM_Ok;
- else if (!ItemPointerEquals(&oldtup.t_self, &oldtup.t_data->t_ctid) ||
- HeapTupleHeaderIndicatesMovedPartitions(oldtup.t_data))
+ else if (!ItemPointerEquals(&oldtup.t_self, &oldtup.t_data->t_ctid))
result = TM_Updated;
else
result = TM_Deleted;
@@ -4485,8 +4483,7 @@ l3:
HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_data->t_infomask) ||
HeapTupleHeaderIsOnlyLocked(tuple->t_data))
result = TM_Ok;
- else if (!ItemPointerEquals(&tuple->t_self, &tuple->t_data->t_ctid) ||
- HeapTupleHeaderIndicatesMovedPartitions(tuple->t_data))
+ else if (!ItemPointerEquals(&tuple->t_self, &tuple->t_data->t_ctid))
result = TM_Updated;
else
result = TM_Deleted;
@@ -5059,8 +5056,7 @@ test_lockmode_for_conflict(MultiXactStatus status, TransactionId xid,
LOCKMODE_from_mxstatus(wantedstatus)))
{
/* bummer */
- if (!ItemPointerEquals(&tup->t_self, &tup->t_data->t_ctid) ||
- HeapTupleHeaderIndicatesMovedPartitions(tup->t_data))
+ if (!ItemPointerEquals(&tup->t_self, &tup->t_data->t_ctid))
return TM_Updated;
else
return TM_Deleted;
diff --git a/src/backend/access/heap/heapam_visibility.c b/src/backend/access/heap/heapam_visibility.c
index 80bd494076..cab6a48a5d 100644
--- a/src/backend/access/heap/heapam_visibility.c
+++ b/src/backend/access/heap/heapam_visibility.c
@@ -607,8 +607,7 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
{
if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
return TM_Ok;
- if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid) ||
- HeapTupleHeaderIndicatesMovedPartitions(tuple))
+ if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
return TM_Updated; /* updated by other */
else
return TM_Deleted; /* deleted by other */
@@ -653,8 +652,7 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
if (TransactionIdDidCommit(xmax))
{
- if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid) ||
- HeapTupleHeaderIndicatesMovedPartitions(tuple))
+ if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
return TM_Updated;
else
return TM_Deleted;
@@ -714,8 +712,7 @@ HeapTupleSatisfiesUpdate(HeapTuple htup, CommandId curcid,
SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
HeapTupleHeaderGetRawXmax(tuple));
- if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid) ||
- HeapTupleHeaderIndicatesMovedPartitions(tuple))
+ if (!ItemPointerEquals(&htup->t_self, &tuple->t_ctid))
return TM_Updated; /* updated by other */
else
return TM_Deleted; /* deleted by other */
--
2.20.1
