From: Kevin Grittner <Kevin.Grittner@wicourts.gov>
Date: Sun, 5 Dec 2010 20:55:46 +0000 (-0600)
Subject: Prevent early rollback of two-transaction write skew.
X-Git-Url: http://git.postgresql.org/gitweb/static/gitweb.js?a=commitdiff_plain;h=refs%2Fheads%2Fidle;p=users%2Fkgrittn%2Fpostgres.git

Prevent early rollback of two-transaction write skew.
---

diff --git a/src/backend/storage/lmgr/predicate.c b/src/backend/storage/lmgr/predicate.c
index 96f6c23a0f..5fec4b60f0 100644
--- a/src/backend/storage/lmgr/predicate.c
+++ b/src/backend/storage/lmgr/predicate.c
@@ -2689,7 +2689,7 @@ OnConflict_CheckForSerializationFailure(const SERIALIZABLEXACT *reader,
 						 offsetof(RWConflictData, outLink));
 		while (conflict)
 		{
-			if (reader == conflict->sxactIn
+			if ((reader == conflict->sxactIn && SxactIsCommitted(reader))
 				|| (SxactIsCommitted(conflict->sxactIn)
 					&& !SxactIsCommitted(reader)
 					&& (!SxactIsReadOnly(reader)
@@ -2783,9 +2783,10 @@ PreCommit_CheckForSerializationFailure(void)
 							 offsetof(RWConflictData, inLink));
 			while (farConflict)
 			{
-				if (!SxactIsCommitted(farConflict->sxactOut)
-					&& !SxactIsReadOnly(farConflict->sxactOut)
-					&& !SxactIsRolledBack(farConflict->sxactOut))
+				if (farConflict->sxactOut == MySerializableXact
+					|| (!SxactIsCommitted(farConflict->sxactOut)
+						&& !SxactIsReadOnly(farConflict->sxactOut)
+						&& !SxactIsRolledBack(farConflict->sxactOut)))
 				{
 					nearConflict->sxactOut->flags |= SXACT_FLAG_INTERRUPT;
 					CancelVirtualTransaction(nearConflict->sxactOut->tag.vxid, 0);