1 files changed, 5 insertions, 218 deletions

diff --git a/src/backend/utils/time/tqual.c b/src/backend/utils/time/tqual.c
index da2ce1825e0..38bb704a4d8 100644
--- a/src/backend/utils/time/tqual.c
+++ b/src/backend/utils/time/tqual.c
@@ -30,10 +30,8 @@
  *
  *	 HeapTupleSatisfiesMVCC()
  *		  visible to supplied snapshot, excludes current command
- *	 HeapTupleSatisfiesNow()
- *		  visible to instant snapshot, excludes current command
  *	 HeapTupleSatisfiesUpdate()
- *		  like HeapTupleSatisfiesNow(), but with user-supplied command
+ *		  visible to instant snapshot, with user-supplied command
  *		  counter and more complex result
  *	 HeapTupleSatisfiesSelf()
  *		  visible to instant snapshot and current command
@@ -68,7 +66,6 @@
 
 
 /* Static variables representing various special snapshot semantics */
-SnapshotData SnapshotNowData = {HeapTupleSatisfiesNow};
 SnapshotData SnapshotSelfData = {HeapTupleSatisfiesSelf};
 SnapshotData SnapshotAnyData = {HeapTupleSatisfiesAny};
 SnapshotData SnapshotToastData = {HeapTupleSatisfiesToast};
@@ -324,212 +321,6 @@ HeapTupleSatisfiesSelf(HeapTuple htup, Snapshot snapshot, Buffer buffer)
 }
 
 /*
- * HeapTupleSatisfiesNow
- *		True iff heap tuple is valid "now".
- *
- *	Here, we consider the effects of:
- *		all committed transactions (as of the current instant)
- *		previous commands of this transaction
- *
- * Note we do _not_ include changes made by the current command.  This
- * solves the "Halloween problem" wherein an UPDATE might try to re-update
- * its own output tuples, http://en.wikipedia.org/wiki/Halloween_Problem.
- *
- * Note:
- *		Assumes heap tuple is valid.
- *
- * The satisfaction of "now" requires the following:
- *
- * ((Xmin == my-transaction &&				inserted by the current transaction
- *	 Cmin < my-command &&					before this command, and
- *	 (Xmax is null ||						the row has not been deleted, or
- *	  (Xmax == my-transaction &&			it was deleted by the current transaction
- *	   Cmax >= my-command)))				but not before this command,
- * ||										or
- *	(Xmin is committed &&					the row was inserted by a committed transaction, and
- *		(Xmax is null ||					the row has not been deleted, or
- *		 (Xmax == my-transaction &&			the row is being deleted by this transaction
- *		  Cmax >= my-command) ||			but it's not deleted "yet", or
- *		 (Xmax != my-transaction &&			the row was deleted by another transaction
- *		  Xmax is not committed))))			that has not been committed
- *
- */
-bool
-HeapTupleSatisfiesNow(HeapTuple htup, Snapshot snapshot, Buffer buffer)
-{
-	HeapTupleHeader tuple = htup->t_data;
-	Assert(ItemPointerIsValid(&htup->t_self));
-	Assert(htup->t_tableOid != InvalidOid);
-
-	if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
-	{
-		if (tuple->t_infomask & HEAP_XMIN_INVALID)
-			return false;
-
-		/* Used by pre-9.0 binary upgrades */
-		if (tuple->t_infomask & HEAP_MOVED_OFF)
-		{
-			TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
-
-			if (TransactionIdIsCurrentTransactionId(xvac))
-				return false;
-			if (!TransactionIdIsInProgress(xvac))
-			{
-				if (TransactionIdDidCommit(xvac))
-				{
-					SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
-								InvalidTransactionId);
-					return false;
-				}
-				SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
-							InvalidTransactionId);
-			}
-		}
-		/* Used by pre-9.0 binary upgrades */
-		else if (tuple->t_infomask & HEAP_MOVED_IN)
-		{
-			TransactionId xvac = HeapTupleHeaderGetXvac(tuple);
-
-			if (!TransactionIdIsCurrentTransactionId(xvac))
-			{
-				if (TransactionIdIsInProgress(xvac))
-					return false;
-				if (TransactionIdDidCommit(xvac))
-					SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
-								InvalidTransactionId);
-				else
-				{
-					SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
-								InvalidTransactionId);
-					return false;
-				}
-			}
-		}
-		else if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetXmin(tuple)))
-		{
-			if (HeapTupleHeaderGetCmin(tuple) >= GetCurrentCommandId(false))
-				return false;	/* inserted after scan started */
-
-			if (tuple->t_infomask & HEAP_XMAX_INVALID)	/* xid invalid */
-				return true;
-
-			if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))	/* not deleter */
-				return true;
-
-			if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
-			{
-				TransactionId xmax;
-
-				xmax = HeapTupleGetUpdateXid(tuple);
-				if (!TransactionIdIsValid(xmax))
-					return true;
-
-				/* updating subtransaction must have aborted */
-				if (!TransactionIdIsCurrentTransactionId(xmax))
-					return true;
-				else
-					return false;
-			}
-
-			if (!TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
-			{
-				/* deleting subtransaction must have aborted */
-				SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
-							InvalidTransactionId);
-				return true;
-			}
-
-			if (HeapTupleHeaderGetCmax(tuple) >= GetCurrentCommandId(false))
-				return true;	/* deleted after scan started */
-			else
-				return false;	/* deleted before scan started */
-		}
-		else if (TransactionIdIsInProgress(HeapTupleHeaderGetXmin(tuple)))
-			return false;
-		else if (TransactionIdDidCommit(HeapTupleHeaderGetXmin(tuple)))
-			SetHintBits(tuple, buffer, HEAP_XMIN_COMMITTED,
-						HeapTupleHeaderGetXmin(tuple));
-		else
-		{
-			/* it must have aborted or crashed */
-			SetHintBits(tuple, buffer, HEAP_XMIN_INVALID,
-						InvalidTransactionId);
-			return false;
-		}
-	}
-
-	/* by here, the inserting transaction has committed */
-
-	if (tuple->t_infomask & HEAP_XMAX_INVALID)	/* xid invalid or aborted */
-		return true;
-
-	if (tuple->t_infomask & HEAP_XMAX_COMMITTED)
-	{
-		if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
-			return true;
-		return false;
-	}
-
-	if (tuple->t_infomask & HEAP_XMAX_IS_MULTI)
-	{
-		TransactionId xmax;
-
-		if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
-			return true;
-
-		xmax = HeapTupleGetUpdateXid(tuple);
-		if (!TransactionIdIsValid(xmax))
-			return true;
-		if (TransactionIdIsCurrentTransactionId(xmax))
-		{
-			if (HeapTupleHeaderGetCmax(tuple) >= GetCurrentCommandId(false))
-				return true;	/* deleted after scan started */
-			else
-				return false;	/* deleted before scan started */
-		}
-		if (TransactionIdIsInProgress(xmax))
-			return true;
-		if (TransactionIdDidCommit(xmax))
-			return false;
-		return true;
-	}
-
-	if (TransactionIdIsCurrentTransactionId(HeapTupleHeaderGetRawXmax(tuple)))
-	{
-		if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
-			return true;
-		if (HeapTupleHeaderGetCmax(tuple) >= GetCurrentCommandId(false))
-			return true;		/* deleted after scan started */
-		else
-			return false;		/* deleted before scan started */
-	}
-
-	if (TransactionIdIsInProgress(HeapTupleHeaderGetRawXmax(tuple)))
-		return true;
-
-	if (!TransactionIdDidCommit(HeapTupleHeaderGetRawXmax(tuple)))
-	{
-		/* it must have aborted or crashed */
-		SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
-					InvalidTransactionId);
-		return true;
-	}
-
-	/* xmax transaction committed */
-
-	if (HEAP_XMAX_IS_LOCKED_ONLY(tuple->t_infomask))
-	{
-		SetHintBits(tuple, buffer, HEAP_XMAX_INVALID,
-					InvalidTransactionId);
-		return true;
-	}
-
-	SetHintBits(tuple, buffer, HEAP_XMAX_COMMITTED,
-				HeapTupleHeaderGetRawXmax(tuple));
-	return false;
-}
-
-/*
  * HeapTupleSatisfiesAny
  *		Dummy "satisfies" routine: any tuple satisfies SnapshotAny.
  */
@@ -614,10 +405,10 @@ HeapTupleSatisfiesToast(HeapTuple htup, Snapshot snapshot,
 /*
  * HeapTupleSatisfiesUpdate
  *
- *	Same logic as HeapTupleSatisfiesNow, but returns a more detailed result
- *	code, since UPDATE needs to know more than "is it visible?".  Also,
- *	tuples of my own xact are tested against the passed CommandId not
- *	CurrentCommandId.
+ *	This function returns a more detailed result code than most of the
+ *	functions in this file, since UPDATE needs to know more than "is it
+ *	visible?".  It also allows for user-supplied CommandId rather than
+ *	relying on CurrentCommandId.
  *
  *	The possible return codes are:
  *
@@ -1051,10 +842,6 @@ HeapTupleSatisfiesDirty(HeapTuple htup, Snapshot snapshot,
  *		transactions started after the snapshot was taken
  *		changes made by the current command
  *
- * This is the same as HeapTupleSatisfiesNow, except that transactions that
- * were in progress or as yet unstarted when the snapshot was taken will
- * be treated as uncommitted, even if they have committed by now.
- *
  * (Notice, however, that the tuple status hint bits will be updated on the
  * basis of the true state of the transaction, even if we then pretend we
  * can't see it.)