New CHECKPOINT command.

Auto removing of offline log files and creating new file
at checkpoint time.

src/backend/access/transam/xact.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.79 2000/10/29 18:33:41 vadim Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/transam/xact.c,v 1.80 2000/11/05 22:50:19 vadim Exp $
  *
  * NOTES
  *		Transaction aborts can now occur two ways:
@@ -678,7 +678,7 @@ RecordTransactionCommit()
 	leak = BufferPoolCheckLeak();
 
 #ifdef XLOG
-	if (MyLastRecPtr.xlogid != 0 || MyLastRecPtr.xrecoff != 0)
+	if (MyLastRecPtr.xrecoff != 0)
 	{
 		xl_xact_commit	xlrec;
 		struct timeval	delay;
@@ -701,7 +701,6 @@ RecordTransactionCommit()
 		delay.tv_usec = CommitDelay;
 		(void) select(0, NULL, NULL, NULL, &delay);
 		XLogFlush(recptr);
-		MyLastRecPtr.xlogid = 0;
 		MyLastRecPtr.xrecoff = 0;
 
 		TransactionIdCommit(xid);
@@ -836,7 +835,7 @@ RecordTransactionAbort(void)
 		TransactionIdAbort(xid);
 
 #ifdef XLOG
-	if (MyLastRecPtr.xlogid != 0 || MyLastRecPtr.xrecoff != 0)
+	if (MyLastRecPtr.xrecoff != 0)
 	{
 		xl_xact_abort	xlrec;
 		XLogRecPtr		recptr;
@@ -844,6 +843,8 @@ RecordTransactionAbort(void)
 		xlrec.xtime = time(NULL);
 		recptr = XLogInsert(RM_XACT_ID, XLOG_XACT_ABORT,
 			(char*) &xlrec, SizeOfXactAbort, NULL, 0);
+
+		MyProc->logRec.xrecoff = 0;
 	}
 #endif
 
@@ -1189,7 +1190,6 @@ AbortTransaction(void)
 	AtEOXact_Files();
 
 	/* Here we'll rollback xaction changes */
-	MyLastRecPtr.xlogid = 0;
 	MyLastRecPtr.xrecoff = 0;
 
 	AtAbort_Locks();

src/backend/access/transam/xlog.c

@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.23 2000/11/03 11:39:35 vadim Exp $
+ * $Header: /cvsroot/pgsql/src/backend/access/transam/xlog.c,v 1.24 2000/11/05 22:50:19 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -16,6 +16,8 @@
 #include <errno.h>
 #include <sys/stat.h>
 #include <sys/time.h>
+#include <sys/types.h>
+#include <dirent.h>
 
 #include "postgres.h"
 
@@ -48,7 +50,10 @@ StartUpID	ThisStartUpID = 0;
 
 int			XLOG_DEBUG = 1;
 
+/* To read/update control file and create new log file */
 SPINLOCK	ControlFileLockId;
+
+/* To generate new xid */
 SPINLOCK	XidGenLockId;
 
 extern VariableCache ShmemVariableCache;
@@ -91,19 +96,20 @@ typedef struct XLogCtlWrite
 
 typedef struct XLogCtlData
 {
-	XLogCtlInsert Insert;
-	XLgwrRqst	LgwrRqst;
-	XLgwrResult LgwrResult;
-	XLogCtlWrite Write;
-	char	   *pages;
-	XLogRecPtr *xlblocks;		/* 1st byte ptr-s + BLCKSZ */
-	uint32		XLogCacheByte;
-	uint32		XLogCacheBlck;
-	StartUpID	ThisStartUpID;
+	XLogCtlInsert	Insert;
+	XLgwrRqst		LgwrRqst;
+	XLgwrResult		LgwrResult;
+	XLogCtlWrite	Write;
+	char		   *pages;
+	XLogRecPtr	   *xlblocks;		/* 1st byte ptr-s + BLCKSZ */
+	uint32			XLogCacheByte;
+	uint32			XLogCacheBlck;
+	StartUpID		ThisStartUpID;
 #ifdef HAS_TEST_AND_SET
-	slock_t		insert_lck;
-	slock_t		info_lck;
-	slock_t		lgwr_lck;
+	slock_t			insert_lck;
+	slock_t			info_lck;
+	slock_t			lgwr_lck;
+	slock_t			chkp_lck;		/* checkpoint lock */
 #endif
 } XLogCtlData;
 
@@ -133,6 +139,7 @@ typedef struct ControlFileData
 	uint32		blcksz;			/* block size for this DB */
 	uint32		relseg_size;	/* blocks per segment of large relation */
 	uint32		catalog_version_no;		/* internal version number */
+	char		archdir[MAXPGPATH];		/* where to move offline log files */
 
 	/*
 	 * MORE DATA FOLLOWS AT THE END OF THIS STRUCTURE - locations of data
@@ -170,6 +177,10 @@ typedef struct CheckPoint
 			snprintf(path, MAXPGPATH, "%s%c%08X%08X",	\
 					 XLogDir, SEP_CHAR, log, seg)
 
+#define XLogTempFileName(path, log, seg)	\
+			snprintf(path, MAXPGPATH, "%s%cT%08X%08X",	\
+					 XLogDir, SEP_CHAR, log, seg)
+
 #define PrevBufIdx(curridx)		\
 		((curridx == 0) ? XLogCtl->XLogCacheBlck : (curridx - 1))
 
@@ -198,7 +209,7 @@ typedef struct CheckPoint
 
 static void GetFreeXLBuffer(void);
 static void XLogWrite(char *buffer);
-static int	XLogFileInit(uint32 log, uint32 seg);
+static int	XLogFileInit(uint32 log, uint32 seg, bool *usexistent);
 static int	XLogFileOpen(uint32 log, uint32 seg, bool econt);
 static XLogRecord *ReadRecord(XLogRecPtr *RecPtr, char *buffer);
 static char *str_time(time_t tnow);
@@ -672,6 +683,7 @@ XLogWrite(char *buffer)
 	char	   *from;
 	uint32		wcnt = 0;
 	int			i = 0;
+	bool		usexistent;
 
 	for (; XLByteLT(LgwrResult.Write, LgwrRqst.Write);)
 	{
@@ -710,13 +722,18 @@ XLogWrite(char *buffer)
 			logId = LgwrResult.Write.xlogid;
 			logSeg = (LgwrResult.Write.xrecoff - 1) / XLogSegSize;
 			logOff = 0;
-			logFile = XLogFileInit(logId, logSeg);
 			SpinAcquire(ControlFileLockId);
+			/* create/use new log file */
+			usexistent = true;
+			logFile = XLogFileInit(logId, logSeg, &usexistent);
 			ControlFile->logId = logId;
 			ControlFile->logSeg = logSeg + 1;
 			ControlFile->time = time(NULL);
 			UpdateControlFile();
 			SpinRelease(ControlFileLockId);
+			if (!usexistent)	/* there was no file */
+				elog(LOG, "XLogWrite: had to create new log file - "
+					"you probably should do checkpoints more often");
 		}
 
 		if (logFile < 0)
@@ -780,17 +797,39 @@ XLogWrite(char *buffer)
 }
 
 static int
-XLogFileInit(uint32 log, uint32 seg)
+XLogFileInit(uint32 log, uint32 seg, bool *usexistent)
 {
 	char		path[MAXPGPATH];
+	char		tpath[MAXPGPATH];
 	int			fd;
 
 	XLogFileName(path, log, seg);
+
+	/*
+	 * Try to use existent file (checkpoint maker
+	 * creates it sometime).
+	 */
+	if (*usexistent)
+	{
+		fd = BasicOpenFile(path, O_RDWR | PG_BINARY, S_IRUSR | S_IWUSR);
+		if (fd < 0)
+		{
+			if (errno != ENOENT)
+				elog(STOP, "InitOpen(logfile %u seg %u) failed: %d",
+					logId, logSeg, errno);
+		}
+		else
+			return(fd);
+		*usexistent = false;
+	}
+
+	XLogTempFileName(tpath, log, seg);
+	unlink(tpath);
 	unlink(path);
 
-	fd = BasicOpenFile(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, S_IRUSR | S_IWUSR);
+	fd = BasicOpenFile(tpath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, S_IRUSR | S_IWUSR);
 	if (fd < 0)
-		elog(STOP, "Init(logfile %u seg %u) failed: %d",
+		elog(STOP, "InitCreate(logfile %u seg %u) failed: %d",
 			 logId, logSeg, errno);
 
 	if (lseek(fd, XLogSegSize - 1, SEEK_SET) != (off_t) (XLogSegSize - 1))
@@ -809,6 +848,15 @@ XLogFileInit(uint32 log, uint32 seg)
 		elog(STOP, "Lseek(logfile %u seg %u off %u) failed: %d",
 			 log, seg, 0, errno);
 
+	close(fd);
+	link(tpath, path);
+	unlink(tpath);
+
+	fd = BasicOpenFile(path, O_RDWR | PG_BINARY, S_IRUSR | S_IWUSR);
+	if (fd < 0)
+		elog(STOP, "InitReopen(logfile %u seg %u) failed: %d",
+			 logId, logSeg, errno);
+
 	return (fd);
 }
 
@@ -837,6 +885,49 @@ XLogFileOpen(uint32 log, uint32 seg, bool econt)
 	return (fd);
 }
 
+/*
+ * (Re)move offline log files older or equal to passwd one
+ */
+static void
+MoveOfflineLogs(char *archdir, uint32 _logId, uint32 _logSeg)
+{
+	DIR			   *xldir;
+	struct dirent  *xlde;
+	char			lastoff[32];
+	char			path[MAXPGPATH];
+
+	Assert(archdir[0] == 0);	/* ! implemented yet */
+
+	xldir = opendir(XLogDir);
+	if (xldir == NULL)
+		elog(STOP, "MoveOfflineLogs: cannot open xlog dir: %d", errno);
+
+	sprintf(lastoff, "%08X%08X", _logId, _logSeg);
+
+	errno = 0;
+	while ((xlde = readdir(xldir)) != NULL)
+	{
+		if (strlen(xlde->d_name) != 16 || 
+			strspn(xlde->d_name, "0123456789ABCDEF") != 16)
+			continue;
+		if (strcmp(xlde->d_name, lastoff) > 0)
+		{
+			elog(LOG, "MoveOfflineLogs: skip %s", xlde->d_name);
+			errno = 0;
+			continue;
+		}
+		elog(LOG, "MoveOfflineLogs: %s %s", (archdir[0]) ? 
+			"archive" : "remove", xlde->d_name);
+		sprintf(path, "%s%c%s",	XLogDir, SEP_CHAR, xlde->d_name);
+		if (archdir[0] != 0)
+			unlink(path);
+		errno = 0;
+	}
+	if (errno)
+		elog(STOP, "MoveOfflineLogs: cannot read xlog dir: %d", errno);
+	closedir(xldir);
+}
+
 static XLogRecord *
 ReadRecord(XLogRecPtr *RecPtr, char *buffer)
 {
@@ -1183,6 +1274,7 @@ BootStrapXLOG()
 	int			fd;
 	char		buffer[BLCKSZ];
 	CheckPoint	checkPoint;
+	bool		usexistent = false;
 
 #ifdef XLOG
 	XLogPageHeader page = (XLogPageHeader) buffer;
@@ -1217,7 +1309,7 @@ BootStrapXLOG()
 	record->xl_rmid = RM_XLOG_ID;
 	memcpy((char *) record + SizeOfXLogRecord, &checkPoint, sizeof(checkPoint));
 
-	logFile = XLogFileInit(0, 0);
+	logFile = XLogFileInit(0, 0, &usexistent);
 
 	if (write(logFile, buffer, BLCKSZ) != BLCKSZ)
 		elog(STOP, "BootStrapXLOG failed to write logfile: %d", errno);
@@ -1297,6 +1389,7 @@ StartupXLOG()
 	S_INIT_LOCK(&(XLogCtl->insert_lck));
 	S_INIT_LOCK(&(XLogCtl->info_lck));
 	S_INIT_LOCK(&(XLogCtl->lgwr_lck));
+	S_INIT_LOCK(&(XLogCtl->chkp_lck));
 
 	/*
 	 * Open/read Control file
@@ -1556,6 +1649,8 @@ ShutdownXLOG()
 	elog(LOG, "Data Base System shut down at %s", str_time(time(NULL)));
 }
 
+extern XLogRecPtr	GetUndoRecPtr(void);
+
 void
 CreateCheckPoint(bool shutdown)
 {
@@ -1565,6 +1660,21 @@ CreateCheckPoint(bool shutdown)
 	XLogCtlInsert *Insert = &XLogCtl->Insert;
 	uint32		freespace;
 	uint16		curridx;
+	uint32		_logId;
+	uint32		_logSeg;
+	char		archdir[MAXPGPATH];
+
+	if (MyLastRecPtr.xrecoff != 0)
+		elog(ERROR, "CreateCheckPoint: cannot be called inside transaction block");
+ 
+	while (TAS(&(XLogCtl->chkp_lck)))
+	{
+		struct timeval delay = {2, 0};
+
+		if (shutdown)
+			elog(STOP, "Checkpoint lock is busy while data base is shutting down");
+		(void) select(0, NULL, NULL, NULL, &delay);
+	}
 
 	memset(&checkPoint, 0, sizeof(checkPoint));
 	if (shutdown)
@@ -1579,7 +1689,7 @@ CreateCheckPoint(bool shutdown)
 	/* Get REDO record ptr */
 	while (TAS(&(XLogCtl->insert_lck)))
 	{
-		struct timeval delay = {0, 5000};
+		struct timeval delay = {1, 0};
 
 		if (shutdown)
 			elog(STOP, "XLog insert lock is busy while data base is shutting down");
@@ -1615,7 +1725,7 @@ CreateCheckPoint(bool shutdown)
 	FlushBufferPool();
 
 	/* Get UNDO record ptr - should use oldest of PROC->logRec */
-	checkPoint.undo.xrecoff = 0;
+	checkPoint.undo = GetUndoRecPtr();
 
 	if (shutdown && checkPoint.undo.xrecoff != 0)
 		elog(STOP, "Active transaction while data base is shutting down");
@@ -1633,9 +1743,35 @@ CreateCheckPoint(bool shutdown)
 	SpinAcquire(ControlFileLockId);
 	if (shutdown)
 		ControlFile->state = DB_SHUTDOWNED;
-
 #ifdef XLOG
+	else	/* create new log file */
+	{
+		if (recptr.xrecoff % XLogSegSize >= 
+			(uint32) (0.75 * XLogSegSize))
+		{
+			int		lf;
+			bool	usexistent = true;
+
+			_logId = recptr.xlogid;
+			_logSeg = recptr.xrecoff / XLogSegSize;
+			if (_logSeg >= XLogLastSeg)
+			{
+				_logId++;
+				_logSeg = 0;
+			}
+			else
+				_logSeg++;
+			lf = XLogFileInit(_logId, _logSeg, &usexistent);
+			close(lf);
+		}
+	}
+
 	ControlFile->checkPoint = MyLastRecPtr;
+
+	_logId = ControlFile->logId;
+	_logSeg = ControlFile->logSeg - 1;
+	strcpy(archdir, ControlFile->archdir);
+
 #else
 	ControlFile->checkPoint.xlogid = 0;
 	ControlFile->checkPoint.xrecoff = SizeOfXLogPHD;
@@ -1645,6 +1781,33 @@ CreateCheckPoint(bool shutdown)
 	UpdateControlFile();
 	SpinRelease(ControlFileLockId);
 
+#ifdef XLOG
+	/*
+	 * Delete offline log files. Get oldest online
+	 * log file from undo rec if it's valid.
+	 */
+	if (checkPoint.undo.xrecoff != 0)
+	{
+		_logId = checkPoint.undo.xlogid;
+		_logSeg = checkPoint.undo.xrecoff / XLogSegSize;
+	}
+	if (_logId || _logSeg)
+	{
+		if (_logSeg)
+			_logSeg--;
+		else
+		{
+			_logId--;
+			_logSeg = 0;
+		}
+		MoveOfflineLogs(archdir, _logId, _logSeg);
+	}
+
+	S_UNLOCK(&(XLogCtl->chkp_lck));
+
+	MyLastRecPtr.xrecoff = 0;	/* to avoid commit record */
+#endif
+
 	return;
 }
 

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.129 2000/11/05 00:15:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.130 2000/11/05 22:50:19 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2895,6 +2895,9 @@ copyObject(void *from)
 		case T_SetSessionStmt:
 			retval = _copySetSessionStmt(from);
 			break;
+		case T_CheckPointStmt:
+			retval = (void*)makeNode(CheckPointStmt);
+			break;
 
 		case T_A_Expr:
 			retval = _copyAExpr(from);

src/backend/nodes/equalfuncs.c

@@ -20,7 +20,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.79 2000/11/05 00:15:52 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.80 2000/11/05 22:50:19 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2049,6 +2049,9 @@ equal(void *a, void *b)
 		case T_SetSessionStmt:
 			retval = _equalSetSessionStmt(a, b);
 			break;
+		case T_CheckPointStmt:
+			retval = true;
+			break;
 
 		case T_A_Expr:
 			retval = _equalAExpr(a, b);

src/backend/parser/gram.y

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.204 2000/11/05 00:15:54 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/gram.y,v 2.205 2000/11/05 22:50:20 vadim Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -136,7 +136,7 @@ static void doNegateFloat(Value *v);
 		RenameStmt, RevokeStmt, RuleActionStmt, RuleActionStmtOrEmpty,
 		RuleStmt, SelectStmt, SetSessionStmt, TransactionStmt, TruncateStmt,
 		UnlistenStmt, UpdateStmt, VacuumStmt, VariableResetStmt,
-		VariableSetStmt, VariableShowStmt, ViewStmt
+		VariableSetStmt, VariableShowStmt, ViewStmt, CheckPointStmt
 
 %type <node>	select_no_parens, select_clause, simple_select
 
@@ -291,7 +291,7 @@ static void doNegateFloat(Value *v);
 /* Keywords (in SQL92 reserved words) */
 %token	ABSOLUTE, ACTION, ADD, ALL, ALTER, AND, ANY, AS, ASC,
 		BEGIN_TRANS, BETWEEN, BOTH, BY,
-		CASCADE, CASE, CAST, CHAR, CHARACTER, CHECK, CLOSE,
+		CASCADE, CASE, CAST, CHAR, CHARACTER, CHECK, CLOSE, 
 		COALESCE, COLLATE, COLUMN, COMMIT,
 		CONSTRAINT, CONSTRAINTS, CREATE, CROSS, CURRENT_DATE,
 		CURRENT_TIME, CURRENT_TIMESTAMP, CURRENT_USER, CURSOR,
@@ -336,7 +336,7 @@ static void doNegateFloat(Value *v);
  */
 %token	ABORT_TRANS, ACCESS, AFTER, AGGREGATE, ANALYZE,
 		BACKWARD, BEFORE, BINARY, BIT,
-		CACHE, CLUSTER, COMMENT, COPY, CREATEDB, CREATEUSER, CYCLE,
+		CACHE, CHECKPOINT, CLUSTER, COMMENT, COPY, CREATEDB, CREATEUSER, CYCLE,
 		DATABASE, DELIMITERS, DO,
 		EACH, ENCODING, EXCLUSIVE, EXPLAIN, EXTEND,
 		FORCE, FORWARD, FUNCTION, HANDLER,
@@ -470,6 +470,7 @@ stmt :	AlterSchemaStmt
 		| VariableShowStmt
 		| VariableResetStmt
 		| ConstraintsSetStmt
+		| CheckPointStmt
 		| /*EMPTY*/
 			{ $$ = (Node *)NULL; }
 		;
@@ -957,6 +958,16 @@ constraints_set_mode:	DEFERRED
 		;
 
 
+/*
+ * Checkpoint statement
+ */
+CheckPointStmt: CHECKPOINT
+				{
+					CheckPointStmt *n = makeNode(CheckPointStmt);
+					$$ = (Node *)n;
+				}
+			;
+
 /*****************************************************************************
  *
  *	ALTER TABLE variations
@@ -5389,6 +5400,7 @@ TokenId:  ABSOLUTE						{ $$ = "absolute"; }
 		| CACHE							{ $$ = "cache"; }
 		| CASCADE						{ $$ = "cascade"; }
 		| CHAIN							{ $$ = "chain"; }
+		| CHECKPOINT					{ $$ = "checkpoint"; }
 		| CLOSE							{ $$ = "close"; }
 		| COMMENT						{ $$ = "comment"; }
 		| COMMIT						{ $$ = "commit"; }

src/backend/parser/keywords.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.81 2000/09/12 05:09:44 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.82 2000/11/05 22:50:20 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -60,6 +60,7 @@ static ScanKeyword ScanKeywords[] = {
 	{"character", CHARACTER},
 	{"characteristics", CHARACTERISTICS},
 	{"check", CHECK},
+	{"checkpoint", CHECKPOINT},
 	{"close", CLOSE},
 	{"cluster", CLUSTER},
 	{"coalesce", COALESCE},

src/backend/storage/ipc/sinval.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.21 2000/04/12 17:15:37 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/ipc/sinval.c,v 1.22 2000/11/05 22:50:20 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -369,3 +369,40 @@ GetSnapshotData(bool serializable)
 	snapshot->xcnt = count;
 	return snapshot;
 }
+
+/*
+ * GetUndoRecPtr -- returns oldest PROC->logRec.
+ */
+XLogRecPtr	GetUndoRecPtr(void);
+
+XLogRecPtr
+GetUndoRecPtr(void)
+{
+	SISeg	   *segP = shmInvalBuffer;
+	ProcState  *stateP = segP->procState;
+	XLogRecPtr	urec = {0, 0};
+	XLogRecPtr	tempr;
+	int			index;
+
+	SpinAcquire(SInvalLock);
+
+	for (index = 0; index < segP->maxBackends; index++)
+	{
+		SHMEM_OFFSET pOffset = stateP[index].procStruct;
+
+		if (pOffset != INVALID_OFFSET)
+		{
+			PROC	   *proc = (PROC *) MAKE_PTR(pOffset);
+			tempr = proc->logRec;
+			if (tempr.xrecoff == 0)
+				continue;
+			if (urec.xrecoff != 0 && XLByteLT(urec, tempr))
+				continue;
+			urec = tempr;
+		}
+	}
+
+	SpinRelease(SInvalLock);
+
+	return(urec);
+}

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.98 2000/10/22 23:32:41 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.99 2000/11/05 22:50:21 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -44,7 +44,7 @@
 #include "utils/acl.h"
 #include "utils/ps_status.h"
 #include "utils/syscache.h"
-
+#include "access/xlog.h"
 
 /*
  * Error-checking support for DROP commands
@@ -818,6 +818,14 @@ ProcessUtility(Node *parsetree,
 			DropGroup((DropGroupStmt *) parsetree);
 			break;
 
+		case T_CheckPointStmt:
+			{
+				set_ps_display(commandTag = "CHECKPOINT");
+
+				CreateCheckPoint(false);
+			}
+			break;
+
 		case T_ReindexStmt:
 			{
 				ReindexStmt *stmt = (ReindexStmt *) parsetree;

src/include/access/xlog.h

@@ -97,4 +97,6 @@ extern XLogRecPtr XLogInsert(RmgrId rmid, uint8 info,
 			char *buf, uint32 buflen);
 extern void XLogFlush(XLogRecPtr RecPtr);
 
+extern void CreateCheckPoint(bool shutdown);
+
 #endif	 /* XLOG_H */

src/include/nodes/nodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: nodes.h,v 1.81 2000/10/31 10:22:12 petere Exp $
+ * $Id: nodes.h,v 1.82 2000/11/05 22:50:21 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -202,6 +202,7 @@ typedef enum NodeTag
 	T_DropGroupStmt,
 	T_ReindexStmt,
 	T_SetSessionStmt,
+	T_CheckPointStmt,
 
 	T_A_Expr = 700,
 	T_Attr,

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.118 2000/11/05 00:15:53 tgl Exp $
+ * $Id: parsenodes.h,v 1.119 2000/11/05 22:50:21 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -695,6 +695,11 @@ typedef struct SetSessionStmt
 	List	   *args;
 } SetSessionStmt;
 
+typedef struct CheckPointStmt
+{
+	NodeTag		type;
+} CheckPointStmt;
+
 /* ----------------------
  * Set Statement
  * ----------------------