diff --git a/src/backend/access/rmgrdesc/xlogdesc.c b/src/backend/access/rmgrdesc/xlogdesc.c
index 83cc9e896e..5e210b9947 100644
--- a/src/backend/access/rmgrdesc/xlogdesc.c
+++ b/src/backend/access/rmgrdesc/xlogdesc.c
@@ -59,8 +59,8 @@ xlog_desc(StringInfo buf, XLogReaderState *record)
 						 checkpoint->oldestXidDB,
 						 checkpoint->oldestMulti,
 						 checkpoint->oldestMultiDB,
-						 checkpoint->oldestCommitTs,
-						 checkpoint->newestCommitTs,
+						 checkpoint->oldestCommitTsXid,
+						 checkpoint->newestCommitTsXid,
 						 checkpoint->oldestActiveXid,
 				 (info == XLOG_CHECKPOINT_SHUTDOWN) ? "shutdown" : "online");
 	}
diff --git a/src/backend/access/transam/commit_ts.c b/src/backend/access/transam/commit_ts.c
index ed8d98ac8a..a284894862 100644
--- a/src/backend/access/transam/commit_ts.c
+++ b/src/backend/access/transam/commit_ts.c
@@ -217,8 +217,8 @@ TransactionTreeSetCommitTsData(TransactionId xid, int nsubxids,
 	commitTsShared->dataLastCommit.nodeid = nodeid;
 
 	/* and move forwards our endpoint, if needed */
-	if (TransactionIdPrecedes(ShmemVariableCache->newestCommitTs, newestXact))
-		ShmemVariableCache->newestCommitTs = newestXact;
+	if (TransactionIdPrecedes(ShmemVariableCache->newestCommitTsXid, newestXact))
+		ShmemVariableCache->newestCommitTsXid = newestXact;
 	LWLockRelease(CommitTsLock);
 }
 
@@ -285,8 +285,8 @@ TransactionIdGetCommitTsData(TransactionId xid, TimestampTz *ts,
 	int			entryno = TransactionIdToCTsEntry(xid);
 	int			slotno;
 	CommitTimestampEntry entry;
-	TransactionId oldestCommitTs;
-	TransactionId newestCommitTs;
+	TransactionId oldestCommitTsXid;
+	TransactionId newestCommitTsXid;
 
 	/* error if the given Xid doesn't normally commit */
 	if (!TransactionIdIsNormal(xid))
@@ -314,18 +314,18 @@ TransactionIdGetCommitTsData(TransactionId xid, TimestampTz *ts,
 		return *ts != 0;
 	}
 
-	oldestCommitTs = ShmemVariableCache->oldestCommitTs;
-	newestCommitTs = ShmemVariableCache->newestCommitTs;
+	oldestCommitTsXid = ShmemVariableCache->oldestCommitTsXid;
+	newestCommitTsXid = ShmemVariableCache->newestCommitTsXid;
 	/* neither is invalid, or both are */
-	Assert(TransactionIdIsValid(oldestCommitTs) == TransactionIdIsValid(newestCommitTs));
+	Assert(TransactionIdIsValid(oldestCommitTsXid) == TransactionIdIsValid(newestCommitTsXid));
 	LWLockRelease(CommitTsLock);
 
 	/*
 	 * Return empty if the requested value is outside our valid range.
 	 */
-	if (!TransactionIdIsValid(oldestCommitTs) ||
-		TransactionIdPrecedes(xid, oldestCommitTs) ||
-		TransactionIdPrecedes(newestCommitTs, xid))
+	if (!TransactionIdIsValid(oldestCommitTsXid) ||
+		TransactionIdPrecedes(xid, oldestCommitTsXid) ||
+		TransactionIdPrecedes(newestCommitTsXid, xid))
 	{
 		*ts = 0;
 		if (nodeid)
@@ -655,14 +655,14 @@ ActivateCommitTs(void)
 	 * enabled again?  It doesn't look like it does, because there should be a
 	 * checkpoint that sets the value to InvalidTransactionId at end of
 	 * recovery; and so any chance of injecting new transactions without
-	 * CommitTs values would occur after the oldestCommitTs has been set to
+	 * CommitTs values would occur after the oldestCommitTsXid has been set to
 	 * Invalid temporarily.
 	 */
 	LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
-	if (ShmemVariableCache->oldestCommitTs == InvalidTransactionId)
+	if (ShmemVariableCache->oldestCommitTsXid == InvalidTransactionId)
 	{
-		ShmemVariableCache->oldestCommitTs =
-			ShmemVariableCache->newestCommitTs = ReadNewTransactionId();
+		ShmemVariableCache->oldestCommitTsXid =
+			ShmemVariableCache->newestCommitTsXid = ReadNewTransactionId();
 	}
 	LWLockRelease(CommitTsLock);
 
@@ -711,8 +711,8 @@ DeactivateCommitTs(void)
 	TIMESTAMP_NOBEGIN(commitTsShared->dataLastCommit.time);
 	commitTsShared->dataLastCommit.nodeid = InvalidRepOriginId;
 
-	ShmemVariableCache->oldestCommitTs = InvalidTransactionId;
-	ShmemVariableCache->newestCommitTs = InvalidTransactionId;
+	ShmemVariableCache->oldestCommitTsXid = InvalidTransactionId;
+	ShmemVariableCache->newestCommitTsXid = InvalidTransactionId;
 
 	LWLockRelease(CommitTsLock);
 
@@ -832,16 +832,16 @@ SetCommitTsLimit(TransactionId oldestXact, TransactionId newestXact)
 	 * "future" or signal a disabled committs.
 	 */
 	LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
-	if (ShmemVariableCache->oldestCommitTs != InvalidTransactionId)
+	if (ShmemVariableCache->oldestCommitTsXid != InvalidTransactionId)
 	{
-		if (TransactionIdPrecedes(ShmemVariableCache->oldestCommitTs, oldestXact))
-			ShmemVariableCache->oldestCommitTs = oldestXact;
-		if (TransactionIdPrecedes(newestXact, ShmemVariableCache->newestCommitTs))
-			ShmemVariableCache->newestCommitTs = newestXact;
+		if (TransactionIdPrecedes(ShmemVariableCache->oldestCommitTsXid, oldestXact))
+			ShmemVariableCache->oldestCommitTsXid = oldestXact;
+		if (TransactionIdPrecedes(newestXact, ShmemVariableCache->newestCommitTsXid))
+			ShmemVariableCache->newestCommitTsXid = newestXact;
 	}
 	else
 	{
-		Assert(ShmemVariableCache->newestCommitTs == InvalidTransactionId);
+		Assert(ShmemVariableCache->newestCommitTsXid == InvalidTransactionId);
 	}
 	LWLockRelease(CommitTsLock);
 }
@@ -850,12 +850,12 @@ SetCommitTsLimit(TransactionId oldestXact, TransactionId newestXact)
  * Move forwards the oldest commitTS value that can be consulted
  */
 void
-AdvanceOldestCommitTs(TransactionId oldestXact)
+AdvanceOldestCommitTsXid(TransactionId oldestXact)
 {
 	LWLockAcquire(CommitTsLock, LW_EXCLUSIVE);
-	if (ShmemVariableCache->oldestCommitTs != InvalidTransactionId &&
-		TransactionIdPrecedes(ShmemVariableCache->oldestCommitTs, oldestXact))
-		ShmemVariableCache->oldestCommitTs = oldestXact;
+	if (ShmemVariableCache->oldestCommitTsXid != InvalidTransactionId &&
+		TransactionIdPrecedes(ShmemVariableCache->oldestCommitTsXid, oldestXact))
+		ShmemVariableCache->oldestCommitTsXid = oldestXact;
 	LWLockRelease(CommitTsLock);
 }
 
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 71fc8ffa27..06a361a9ed 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -4786,8 +4786,8 @@ BootStrapXLOG(void)
 	checkPoint.oldestXidDB = TemplateDbOid;
 	checkPoint.oldestMulti = FirstMultiXactId;
 	checkPoint.oldestMultiDB = TemplateDbOid;
-	checkPoint.oldestCommitTs = InvalidTransactionId;
-	checkPoint.newestCommitTs = InvalidTransactionId;
+	checkPoint.oldestCommitTsXid = InvalidTransactionId;
+	checkPoint.newestCommitTsXid = InvalidTransactionId;
 	checkPoint.time = (pg_time_t) time(NULL);
 	checkPoint.oldestActiveXid = InvalidTransactionId;
 
@@ -6302,8 +6302,8 @@ StartupXLOG(void)
 					checkPoint.oldestMulti, checkPoint.oldestMultiDB)));
 	ereport(DEBUG1,
 			(errmsg_internal("commit timestamp Xid oldest/newest: %u/%u",
-					checkPoint.oldestCommitTs,
-					checkPoint.newestCommitTs)));
+					checkPoint.oldestCommitTsXid,
+					checkPoint.newestCommitTsXid)));
 	if (!TransactionIdIsNormal(checkPoint.nextXid))
 		ereport(PANIC,
 				(errmsg("invalid next transaction ID")));
@@ -6315,8 +6315,8 @@ StartupXLOG(void)
 	MultiXactSetNextMXact(checkPoint.nextMulti, checkPoint.nextMultiOffset);
 	SetTransactionIdLimit(checkPoint.oldestXid, checkPoint.oldestXidDB);
 	SetMultiXactIdLimit(checkPoint.oldestMulti, checkPoint.oldestMultiDB);
-	SetCommitTsLimit(checkPoint.oldestCommitTs,
-					 checkPoint.newestCommitTs);
+	SetCommitTsLimit(checkPoint.oldestCommitTsXid,
+					 checkPoint.newestCommitTsXid);
 	XLogCtl->ckptXidEpoch = checkPoint.nextXidEpoch;
 	XLogCtl->ckptXid = checkPoint.nextXid;
 
@@ -8334,8 +8334,8 @@ CreateCheckPoint(int flags)
 	LWLockRelease(XidGenLock);
 
 	LWLockAcquire(CommitTsLock, LW_SHARED);
-	checkPoint.oldestCommitTs = ShmemVariableCache->oldestCommitTs;
-	checkPoint.newestCommitTs = ShmemVariableCache->newestCommitTs;
+	checkPoint.oldestCommitTsXid = ShmemVariableCache->oldestCommitTsXid;
+	checkPoint.newestCommitTsXid = ShmemVariableCache->newestCommitTsXid;
 	LWLockRelease(CommitTsLock);
 
 	/* Increase XID epoch if we've wrapped around since last checkpoint */
diff --git a/src/backend/commands/vacuum.c b/src/backend/commands/vacuum.c
index 7c4ef58129..be89b9b86b 100644
--- a/src/backend/commands/vacuum.c
+++ b/src/backend/commands/vacuum.c
@@ -1151,7 +1151,7 @@ vac_truncate_clog(TransactionId frozenXID,
 	 */
 	SetTransactionIdLimit(frozenXID, oldestxid_datoid);
 	SetMultiXactIdLimit(minMulti, minmulti_datoid);
-	AdvanceOldestCommitTs(frozenXID);
+	AdvanceOldestCommitTsXid(frozenXID);
 }
 
 
diff --git a/src/bin/pg_controldata/pg_controldata.c b/src/bin/pg_controldata/pg_controldata.c
index 32e1d81bf2..e7e072f7f3 100644
--- a/src/bin/pg_controldata/pg_controldata.c
+++ b/src/bin/pg_controldata/pg_controldata.c
@@ -271,10 +271,10 @@ main(int argc, char *argv[])
 		   ControlFile.checkPointCopy.oldestMulti);
 	printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
 		   ControlFile.checkPointCopy.oldestMultiDB);
-	printf(_("Latest checkpoint's oldestCommitTs:   %u\n"),
-		   ControlFile.checkPointCopy.oldestCommitTs);
-	printf(_("Latest checkpoint's newestCommitTs:   %u\n"),
-		   ControlFile.checkPointCopy.newestCommitTs);
+	printf(_("Latest checkpoint's oldestCommitTsXid:%u\n"),
+		   ControlFile.checkPointCopy.oldestCommitTsXid);
+	printf(_("Latest checkpoint's newestCommitTsXid:%u\n"),
+		   ControlFile.checkPointCopy.newestCommitTsXid);
 	printf(_("Time of latest checkpoint:            %s\n"),
 		   ckpttime_str);
 	printf(_("Fake LSN counter for unlogged rels:   %X/%X\n"),
diff --git a/src/bin/pg_resetxlog/pg_resetxlog.c b/src/bin/pg_resetxlog/pg_resetxlog.c
index 8826960121..6615aea509 100644
--- a/src/bin/pg_resetxlog/pg_resetxlog.c
+++ b/src/bin/pg_resetxlog/pg_resetxlog.c
@@ -64,8 +64,8 @@ static bool guessed = false;	/* T if we had to guess at any values */
 static const char *progname;
 static uint32 set_xid_epoch = (uint32) -1;
 static TransactionId set_xid = 0;
-static TransactionId set_oldest_commit_ts = 0;
-static TransactionId set_newest_commit_ts = 0;
+static TransactionId set_oldest_commit_ts_xid = 0;
+static TransactionId set_newest_commit_ts_xid = 0;
 static Oid	set_oid = 0;
 static MultiXactId set_mxid = 0;
 static MultiXactOffset set_mxoff = (MultiXactOffset) -1;
@@ -164,14 +164,14 @@ main(int argc, char *argv[])
 				break;
 
 			case 'c':
-				set_oldest_commit_ts = strtoul(optarg, &endptr, 0);
+				set_oldest_commit_ts_xid = strtoul(optarg, &endptr, 0);
 				if (endptr == optarg || *endptr != ',')
 				{
 					fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-c");
 					fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 					exit(1);
 				}
-				set_newest_commit_ts = strtoul(endptr + 1, &endptr2, 0);
+				set_newest_commit_ts_xid = strtoul(endptr + 1, &endptr2, 0);
 				if (endptr2 == endptr + 1 || *endptr2 != '\0')
 				{
 					fprintf(stderr, _("%s: invalid argument for option %s\n"), progname, "-c");
@@ -179,15 +179,15 @@ main(int argc, char *argv[])
 					exit(1);
 				}
 
-				if (set_oldest_commit_ts < 2 &&
-					set_oldest_commit_ts != 0)
+				if (set_oldest_commit_ts_xid < 2 &&
+					set_oldest_commit_ts_xid != 0)
 				{
 					fprintf(stderr, _("%s: transaction ID (-c) must be either 0 or greater than or equal to 2\n"), progname);
 					exit(1);
 				}
 
-				if (set_newest_commit_ts < 2 &&
-					set_newest_commit_ts != 0)
+				if (set_newest_commit_ts_xid < 2 &&
+					set_newest_commit_ts_xid != 0)
 				{
 					fprintf(stderr, _("%s: transaction ID (-c) must be either 0 or greater than or equal to 2\n"), progname);
 					exit(1);
@@ -383,10 +383,10 @@ main(int argc, char *argv[])
 		ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
 	}
 
-	if (set_oldest_commit_ts != 0)
-		ControlFile.checkPointCopy.oldestCommitTs = set_oldest_commit_ts;
-	if (set_newest_commit_ts != 0)
-		ControlFile.checkPointCopy.newestCommitTs = set_newest_commit_ts;
+	if (set_oldest_commit_ts_xid != 0)
+		ControlFile.checkPointCopy.oldestCommitTsXid = set_oldest_commit_ts_xid;
+	if (set_newest_commit_ts_xid != 0)
+		ControlFile.checkPointCopy.newestCommitTsXid = set_newest_commit_ts_xid;
 
 	if (set_oid != 0)
 		ControlFile.checkPointCopy.nextOid = set_oid;
@@ -665,10 +665,10 @@ PrintControlValues(bool guessed)
 		   ControlFile.checkPointCopy.oldestMulti);
 	printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
 		   ControlFile.checkPointCopy.oldestMultiDB);
-	printf(_("Latest checkpoint's oldestCommitTs:   %u\n"),
-		   ControlFile.checkPointCopy.oldestCommitTs);
-	printf(_("Latest checkpoint's newestCommitTs:   %u\n"),
-		   ControlFile.checkPointCopy.newestCommitTs);
+	printf(_("Latest checkpoint's oldestCommitTsXid:%u\n"),
+		   ControlFile.checkPointCopy.oldestCommitTsXid);
+	printf(_("Latest checkpoint's newestCommitTsXid:%u\n"),
+		   ControlFile.checkPointCopy.newestCommitTsXid);
 	printf(_("Maximum data alignment:               %u\n"),
 		   ControlFile.maxAlign);
 	/* we don't print floatFormat since can't say much useful about it */
@@ -751,15 +751,15 @@ PrintNewControlValues()
 			   ControlFile.checkPointCopy.nextXidEpoch);
 	}
 
-	if (set_oldest_commit_ts != 0)
+	if (set_oldest_commit_ts_xid != 0)
 	{
-		printf(_("oldestCommitTs:                       %u\n"),
-			   ControlFile.checkPointCopy.oldestCommitTs);
+		printf(_("oldestCommitTsXid:                    %u\n"),
+			   ControlFile.checkPointCopy.oldestCommitTsXid);
 	}
-	if (set_newest_commit_ts != 0)
+	if (set_newest_commit_ts_xid != 0)
 	{
-		printf(_("newestCommitTs:                       %u\n"),
-			   ControlFile.checkPointCopy.newestCommitTs);
+		printf(_("newestCommitTsXid:                    %u\n"),
+			   ControlFile.checkPointCopy.newestCommitTsXid);
 	}
 }
 
diff --git a/src/include/access/commit_ts.h b/src/include/access/commit_ts.h
index 425f25870f..b11715a2b9 100644
--- a/src/include/access/commit_ts.h
+++ b/src/include/access/commit_ts.h
@@ -43,7 +43,7 @@ extern void ExtendCommitTs(TransactionId newestXact);
 extern void TruncateCommitTs(TransactionId oldestXact);
 extern void SetCommitTsLimit(TransactionId oldestXact,
 				 TransactionId newestXact);
-extern void AdvanceOldestCommitTs(TransactionId oldestXact);
+extern void AdvanceOldestCommitTsXid(TransactionId oldestXact);
 
 /* XLOG stuff */
 #define COMMIT_TS_ZEROPAGE		0x00
diff --git a/src/include/access/transam.h b/src/include/access/transam.h
index 96b3facb14..9ad5761f81 100644
--- a/src/include/access/transam.h
+++ b/src/include/access/transam.h
@@ -126,8 +126,8 @@ typedef struct VariableCacheData
 	/*
 	 * These fields are protected by CommitTsLock
 	 */
-	TransactionId oldestCommitTs;
-	TransactionId newestCommitTs;
+	TransactionId oldestCommitTsXid;
+	TransactionId newestCommitTsXid;
 
 	/*
 	 * These fields are protected by ProcArrayLock.
diff --git a/src/include/catalog/pg_control.h b/src/include/catalog/pg_control.h
index ad1eb4b9cc..0b8bea74a8 100644
--- a/src/include/catalog/pg_control.h
+++ b/src/include/catalog/pg_control.h
@@ -46,9 +46,9 @@ typedef struct CheckPoint
 	MultiXactId oldestMulti;	/* cluster-wide minimum datminmxid */
 	Oid			oldestMultiDB;	/* database with minimum datminmxid */
 	pg_time_t	time;			/* time stamp of checkpoint */
-	TransactionId oldestCommitTs;		/* oldest Xid with valid commit
+	TransactionId oldestCommitTsXid;	/* oldest Xid with valid commit
 										 * timestamp */
-	TransactionId newestCommitTs;		/* newest Xid with valid commit
+	TransactionId newestCommitTsXid;	/* newest Xid with valid commit
 										 * timestamp */
 
 	/*