Remove AMI_OVERRIDE tests from tqual.c routines; they aren't necessary

and just slow down normal operations (only fractionally, but a cycle saved
is a cycle earned).  Improve documentation of AMI_OVERRIDE behavior.

src/backend/access/transam/transam.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/transam.c,v 1.50 2001/11/05 17:46:24 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/transam.c,v 1.51 2002/05/25 20:00:11 tgl Exp $
  *
  * NOTES
  *	  This file contains the high level access-method interface to the
@@ -23,6 +23,18 @@
 #include "access/transam.h"
 
 
+/* ----------------
+ *		Flag indicating that we are bootstrapping.
+ *
+ * Transaction ID generation is disabled during bootstrap; we just use
+ * BootstrapTransactionId.  Also, the transaction ID status-check routines
+ * are short-circuited; they claim that BootstrapTransactionId has already
+ * committed, allowing tuples already inserted to be seen immediately.
+ * ----------------
+ */
+bool		AMI_OVERRIDE = false;
+
+
 static bool TransactionLogTest(TransactionId transactionId, XidStatus status);
 static void TransactionLogUpdate(TransactionId transactionId,
 					 XidStatus status);
@@ -160,7 +172,10 @@ bool							/* true if given transaction committed */
 TransactionIdDidCommit(TransactionId transactionId)
 {
 	if (AMI_OVERRIDE)
+	{
+		Assert(transactionId == BootstrapTransactionId);
 		return true;
+	}
 
 	return TransactionLogTest(transactionId, TRANSACTION_STATUS_COMMITTED);
 }
@@ -176,7 +191,10 @@ bool							/* true if given transaction aborted */
 TransactionIdDidAbort(TransactionId transactionId)
 {
 	if (AMI_OVERRIDE)
+	{
+		Assert(transactionId == BootstrapTransactionId);
 		return false;
+	}
 
 	return TransactionLogTest(transactionId, TRANSACTION_STATUS_ABORTED);
 }
@@ -193,7 +211,10 @@ bool
 TransactionIdIsInProgress(TransactionId transactionId)
 {
 	if (AMI_OVERRIDE)
+	{
+		Assert(transactionId == BootstrapTransactionId);
 		return false;
+	}
 
 	return TransactionLogTest(transactionId, TRANSACTION_STATUS_IN_PROGRESS);
 }
@@ -215,9 +236,6 @@ TransactionIdIsInProgress(TransactionId transactionId)
 void
 TransactionIdCommit(TransactionId transactionId)
 {
-	if (AMI_OVERRIDE)
-		return;
-
 	TransactionLogUpdate(transactionId, TRANSACTION_STATUS_COMMITTED);
 }
 
@@ -231,9 +249,6 @@ TransactionIdCommit(TransactionId transactionId)
 void
 TransactionIdAbort(TransactionId transactionId)
 {
-	if (AMI_OVERRIDE)
-		return;
-
 	TransactionLogUpdate(transactionId, TRANSACTION_STATUS_ABORTED);
 }
 

src/backend/access/transam/varsup.c

@@ -6,7 +6,7 @@
  * Copyright (c) 2000, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.48 2001/10/28 06:25:42 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/varsup.c,v 1.49 2002/05/25 20:00:11 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -93,13 +93,6 @@ ReadNewTransactionId(void)
 {
 	TransactionId xid;
 
-	/*
-	 * During bootstrap initialization, we return the special bootstrap
-	 * transaction id.
-	 */
-	if (AMI_OVERRIDE)
-		return BootstrapTransactionId;
-
 	LWLockAcquire(XidGenLock, LW_SHARED);
 	xid = ShmemVariableCache->nextXid;
 	LWLockRelease(XidGenLock);

src/backend/access/transam/xact.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.124 2002/05/22 21:40:55 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.125 2002/05/25 20:00:12 tgl Exp $
  *
  * NOTES
  *		Transaction aborts can now occur two ways:
@@ -229,13 +229,6 @@ int			CommitSiblings = 5; /* number of concurrent xacts needed to
 static void (*_RollbackFunc) (void *) = NULL;
 static void *_RollbackData = NULL;
 
-/* ----------------
- *		catalog creation transaction bootstrapping flag.
- *		This should be eliminated and added to the transaction
- *		state stuff.  -cim 3/19/90
- * ----------------
- */
-bool		AMI_OVERRIDE = false;
 
 /* ----------------------------------------------------------------
  *					 transaction state accessors
@@ -380,6 +373,11 @@ GetCurrentTransactionStartTimeUsec(int *msec)
 
 /* --------------------------------
  *		TransactionIdIsCurrentTransactionId
+ *
+ * During bootstrap, we cheat and say "it's not my transaction ID" even though
+ * it is.  Along with transam.c's cheat to say that the bootstrap XID is
+ * already committed, this causes the tqual.c routines to see previously
+ * inserted tuples as committed, which is what we need during bootstrap.
  * --------------------------------
  */
 bool
@@ -388,7 +386,10 @@ TransactionIdIsCurrentTransactionId(TransactionId xid)
 	TransactionState s = CurrentTransactionState;
 
 	if (AMI_OVERRIDE)
+	{
+		Assert(xid == BootstrapTransactionId);
 		return false;
+	}
 
 	return TransactionIdEquals(xid, s->transactionIdData);
 }
@@ -403,9 +404,6 @@ CommandIdIsCurrentCommandId(CommandId cid)
 {
 	TransactionState s = CurrentTransactionState;
 
-	if (AMI_OVERRIDE)
-		return false;
-
 	return (cid == s->commandId) ? true : false;
 }
 

src/backend/utils/time/tqual.c

@@ -16,7 +16,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.53 2002/05/24 18:57:56 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/time/tqual.c,v 1.54 2002/05/25 20:00:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -202,9 +202,6 @@ HeapTupleSatisfiesItself(HeapTupleHeader tuple)
 bool
 HeapTupleSatisfiesNow(HeapTupleHeader tuple)
 {
-	if (AMI_OVERRIDE)
-		return true;
-
 	if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
 	{
 		if (tuple->t_infomask & HEAP_XMIN_INVALID)
@@ -375,9 +372,6 @@ HeapTupleSatisfiesUpdate(HeapTuple htuple, CommandId curcid)
 {
 	HeapTupleHeader tuple = htuple->t_data;
 
-	if (AMI_OVERRIDE)
-		return HeapTupleMayBeUpdated;
-
 	if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
 	{
 		if (tuple->t_infomask & HEAP_XMIN_INVALID)
@@ -509,9 +503,6 @@ HeapTupleSatisfiesDirty(HeapTupleHeader tuple)
 	SnapshotDirty->xmin = SnapshotDirty->xmax = InvalidTransactionId;
 	ItemPointerSetInvalid(&(SnapshotDirty->tid));
 
-	if (AMI_OVERRIDE)
-		return true;
-
 	if (!(tuple->t_infomask & HEAP_XMIN_COMMITTED))
 	{
 		if (tuple->t_infomask & HEAP_XMIN_INVALID)
@@ -639,9 +630,6 @@ HeapTupleSatisfiesDirty(HeapTupleHeader tuple)
 bool
 HeapTupleSatisfiesSnapshot(HeapTupleHeader tuple, Snapshot snapshot)
 {
-	if (AMI_OVERRIDE)
-		return true;
-
 	/* XXX this is horribly ugly: */
 	if (ReferentialIntegritySnapshotOverride)
 		return HeapTupleSatisfiesNow(tuple);

src/include/access/transam.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: transam.h,v 1.44 2001/11/05 17:46:31 momjian Exp $
+ * $Id: transam.h,v 1.45 2002/05/25 20:00:12 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -92,6 +92,13 @@ typedef VariableCacheData *VariableCache;
  * ----------------
  */
 
+/* in transam/transam.c */
+extern bool AMI_OVERRIDE;
+
+/* in transam/varsup.c */
+extern VariableCache ShmemVariableCache;
+
+
 /*
  * prototypes for functions in transam/transam.c
  */
@@ -111,15 +118,4 @@ extern TransactionId ReadNewTransactionId(void);
 extern Oid	GetNewObjectId(void);
 extern void CheckMaxObjectId(Oid assigned_oid);
 
-/* ----------------
- *		global variable extern declarations
- * ----------------
- */
-
-/* in xact.c */
-extern bool AMI_OVERRIDE;
-
-/* in varsup.c */
-extern VariableCache ShmemVariableCache;
-
 #endif   /* TRAMSAM_H */