From 3152996ffb8e9954927268b12f11814902e90166 Mon Sep 17 00:00:00 2001
From: Vadim B. Mikheev
Date: Fri, 29 Aug 1997 09:05:25 +0000
Subject: Fix very old bug which made tuples changed/inserted by a commnd
 visible to command itself (so we had multiple update of updated tuples, etc).

---
 src/backend/access/transam/xact.c | 42 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 41 insertions(+), 1 deletion(-)

(limited to 'src/backend/access')

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 903cca41130..5ac4a42c7c7 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.12 1997/08/19 21:30:19 momjian Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.13 1997/08/29 09:02:11 vadim Exp $
  *	
  * NOTES
  *	Transaction aborts can now occur two ways:
@@ -377,6 +377,22 @@ GetCurrentCommandId()
     return s->commandId;
 }
 
+CommandId
+GetScanCommandId()
+{
+    TransactionState s = CurrentTransactionState;
+    
+    /* ----------------
+     *	if the transaction system is disabled, we return
+     *  the special "disabled" command id.
+     * ----------------
+     */
+    if (s->state == TRANS_DISABLED)
+	return (CommandId) DisabledCommandId;
+    
+    return s->scanCommandId;
+}
+
 
 /* --------------------------------
  *	GetCurrentTransactionStartTime
@@ -432,6 +448,18 @@ CommandIdIsCurrentCommandId(CommandId cid)
 	(cid == s->commandId) ? true : false;
 }
 
+bool
+CommandIdGEScanCommandId(CommandId cid)
+{
+    TransactionState s = CurrentTransactionState;
+    
+    if (AMI_OVERRIDE)
+	return false;
+    
+    return 	
+	(cid >= s->scanCommandId) ? true : false;
+}
+
 
 /* --------------------------------
  *	ClearCommandIdCounterOverflowFlag
@@ -458,11 +486,22 @@ CommandCounterIncrement()
 	elog(WARN, "You may only have 65535 commands per transaction");
     }
     
+    CurrentTransactionStateData.scanCommandId = 
+    		CurrentTransactionStateData.commandId;
+    
     /* make cache changes visible to me */
     AtCommit_Cache();
     AtStart_Cache();
 }
 
+void 
+SetScanCommandId (CommandId savedId)
+{
+
+    CurrentTransactionStateData.scanCommandId = savedId;
+    
+}
+
 /* ----------------------------------------------------------------
  *		        initialization stuff
  * ----------------------------------------------------------------
@@ -757,6 +796,7 @@ StartTransaction()
      * ----------------
      */
     s->commandId = 		FirstCommandId;
+    s->scanCommandId = 		FirstCommandId;
     s->startTime = 		GetCurrentAbsoluteTime();
     
     /* ----------------
-- 
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