Back-patch fix to ensure a checkpoint occurs before truncating CLOG,

even if no recent WAL activity has occurred.

src/backend/access/transam/clog.c

@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/access/transam/clog.c,v 1.7 2001/10/28 06:25:42 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/transam/clog.c,v 1.7.2.1 2002/09/30 19:55:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -810,8 +810,8 @@ TruncateCLOG(TransactionId oldestXact)
 	if (!ScanCLOGDirectory(cutoffPage, false))
 		return;					/* nothing to remove */
 
-	/* Perform a CHECKPOINT */
+	/* Perform a forced CHECKPOINT */
-	CreateCheckPoint(false);
+	CreateCheckPoint(false, true);
 
 	/*
 	 * Scan CLOG shared memory and remove any pages preceding the cutoff

src/backend/access/transam/xlog.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.86.2.1 2002/03/15 19:20:43 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.86.2.2 2002/09/30 19:55:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2737,7 +2737,7 @@ StartupXLOG(void)
 		 * checkpoint to become prevCheckPoint...
 		 */
 		ControlFile->checkPoint = checkPointLoc;
-		CreateCheckPoint(true);
+		CreateCheckPoint(true, true);
 		XLogCloseRelationCache();
 	}
 
@@ -2894,7 +2894,7 @@ ShutdownXLOG(void)
 
 	CritSectionCount++;
 	CreateDummyCaches();
-	CreateCheckPoint(true);
+	CreateCheckPoint(true, true);
 	ShutdownCLOG();
 	CritSectionCount--;
 
@@ -2905,7 +2905,7 @@ ShutdownXLOG(void)
  * Perform a checkpoint --- either during shutdown, or on-the-fly
  */
 void
-CreateCheckPoint(bool shutdown)
+CreateCheckPoint(bool shutdown, bool force)
 {
 	CheckPoint	checkPoint;
 	XLogRecPtr	recptr;
@@ -2962,7 +2962,7 @@ CreateCheckPoint(bool shutdown)
 	 * match the end of the last checkpoint record, and its redo pointer
 	 * must point to itself.
 	 */
-	if (!shutdown)
+	if (!shutdown && !force)
 	{
 		XLogRecPtr	curInsert;
 

src/backend/bootstrap/bootstrap.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.120.2.1 2002/03/15 19:20:44 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/bootstrap/bootstrap.c,v 1.120.2.2 2002/09/30 19:55:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -379,7 +379,7 @@ BootstrapMain(int argc, char *argv[])
 			if (IsUnderPostmaster)
 				InitDummyProcess();		/* needed to get LWLocks */
 			CreateDummyCaches();
-			CreateCheckPoint(false);
+			CreateCheckPoint(false, false);
 			SetSavedRedoRecPtr(); /* pass redo ptr back to postmaster */
 			proc_exit(0);		/* done */
 
@@ -433,7 +433,7 @@ BootstrapMain(int argc, char *argv[])
 	Int_yyparse();
 
 	SetProcessingMode(NormalProcessing);
-	CreateCheckPoint(true);
+	CreateCheckPoint(true, true);
 	SetProcessingMode(BootstrapProcessing);
 
 	/* clean up processing */

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.125.2.1 2002/02/26 23:48:46 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.125.2.2 2002/09/30 19:55:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -775,7 +775,7 @@ ProcessUtility(Node *parsetree,
 			{
 				if (!superuser())
 					elog(ERROR, "permission denied");
-				CreateCheckPoint(false);
+				CreateCheckPoint(false, false);
 			}
 			break;
 

src/include/access/xlog.h

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: xlog.h,v 1.28.2.1 2002/03/15 19:20:47 tgl Exp $
+ * $Id: xlog.h,v 1.28.2.2 2002/09/30 19:55:08 tgl Exp $
  */
 #ifndef XLOG_H
 #define XLOG_H
@@ -204,7 +204,7 @@ extern void XLOGPathInit(void);
 extern void BootStrapXLOG(void);
 extern void StartupXLOG(void);
 extern void ShutdownXLOG(void);
-extern void CreateCheckPoint(bool shutdown);
+extern void CreateCheckPoint(bool shutdown, bool force);
 extern void SetThisStartUpID(void);
 extern void XLogPutNextOid(Oid nextOid);
 extern void SetSavedRedoRecPtr(void);