Rename locking structure names to be clearer. Add narrative to

backend flowchart.

9 files changed, 324 insertions, 311 deletions

diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index d4162387b68..4b83c9c0d16 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.31 1998/06/28 21:17:34 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/lock.c,v 1.32 1998/06/30 02:33:31 momjian Exp $
  *
  * NOTES
  *	  Outside modules can create a lock table and acquire/release
@@ -18,7 +18,7 @@
  *
  *	Interface:
  *
- *	LockAcquire(), LockRelease(), LockTableInit().
+ *	LockAcquire(), LockRelease(), LockMethodTableInit().
  *
  *	LockReplace() is called only within this module and by the
  *		lkchain module.  It releases a lock without looking
@@ -51,8 +51,7 @@
 #include "access/transam.h"
 
 static int
-WaitOnLock(LOCKTAB *ltable, LockTableId tableId, LOCK *lock,
-		   LOCKTYPE locktype);
+WaitOnLock(LOCKMETHOD lockmethod, LOCK *lock, LOCKMODE lockmode);
 
 /*#define LOCK_MGR_DEBUG*/
 
@@ -134,8 +133,8 @@ SPINLOCK	LockMgrLock;		/* in Shmem or created in
 
 /* This is to simplify/speed up some bit arithmetic */
 
-static MASK BITS_OFF[MAX_LOCKTYPES];
-static MASK BITS_ON[MAX_LOCKTYPES];
+static MASK BITS_OFF[MAX_LOCKMODES];
+static MASK BITS_ON[MAX_LOCKMODES];
 
 /* -----------------
  * XXX Want to move this to this file
@@ -144,16 +143,12 @@ static MASK BITS_ON[MAX_LOCKTYPES];
 static bool LockingIsDisabled;
 
 /* -------------------
- * map from tableId to the lock table structure
+ * map from lockmethod to the lock table structure
  * -------------------
  */
-static LOCKTAB *AllTables[MAX_TABLES];
+static LOCKMETHODTABLE *LockMethodTable[MAX_LOCK_METHODS];
 
-/* -------------------
- * no zero-th table
- * -------------------
- */
-static int	NumTables;
+static int	NumLockMethods;
 
 /* -------------------
  * InitLocks -- Init the lock module.  Create a private data
@@ -168,10 +163,10 @@ InitLocks()
 
 	bit = 1;
 	/* -------------------
-	 * remember 0th locktype is invalid
+	 * remember 0th lockmode is invalid
 	 * -------------------
 	 */
-	for (i = 0; i < MAX_LOCKTYPES; i++, bit <<= 1)
+	for (i = 0; i < MAX_LOCKMODES; i++, bit <<= 1)
 	{
 		BITS_ON[i] = bit;
 		BITS_OFF[i] = ~bit;
@@ -190,30 +185,30 @@ LockDisable(int status)
 
 
 /*
- * LockTypeInit -- initialize the lock table's lock type
+ * LockMethodInit -- initialize the lock table's lock type
  *		structures
  *
  * Notes: just copying.  Should only be called once.
  */
 static void
-LockTypeInit(LOCKTAB *ltable,
+LockMethodInit(LOCKMETHODTABLE *lockMethodTable,
 			 MASK *conflictsP,
 			 int *prioP,
-			 int ntypes)
+			 int numModes)
 {
 	int			i;
 
-	ltable->ctl->nLockTypes = ntypes;
-	ntypes++;
-	for (i = 0; i < ntypes; i++, prioP++, conflictsP++)
+	lockMethodTable->ctl->numLockModes = numModes;
+	numModes++;
+	for (i = 0; i < numModes; i++, prioP++, conflictsP++)
 	{
-		ltable->ctl->conflictTab[i] = *conflictsP;
-		ltable->ctl->prio[i] = *prioP;
+		lockMethodTable->ctl->conflictTab[i] = *conflictsP;
+		lockMethodTable->ctl->prio[i] = *prioP;
 	}
 }
 
 /*
- * LockTableInit -- initialize a lock table structure
+ * LockMethodTableInit -- initialize a lock table structure
  *
  * Notes:
  *		(a) a lock table has four separate entries in the shmem index
@@ -222,23 +217,23 @@ LockTypeInit(LOCKTAB *ltable,
  *		is wasteful, in this case, but not much space is involved.
  *
  */
-LockTableId
-LockTableInit(char *tabName,
+LOCKMETHOD
+LockMethodTableInit(char *tabName,
 			MASK *conflictsP,
 			int *prioP,
-			int ntypes)
+			int numModes)
 {
-	LOCKTAB    *ltable;
+	LOCKMETHODTABLE    *lockMethodTable;
 	char	   *shmemName;
 	HASHCTL		info;
 	int			hash_flags;
 	bool		found;
 	int			status = TRUE;
 
-	if (ntypes > MAX_LOCKTYPES)
+	if (numModes > MAX_LOCKMODES)
 	{
-		elog(NOTICE, "LockTableInit: too many lock types %d greater than %d",
-			 ntypes, MAX_LOCKTYPES);
+		elog(NOTICE, "LockMethodTableInit: too many lock types %d greater than %d",
+			 numModes, MAX_LOCKMODES);
 		return (INVALID_TABLEID);
 	}
 
@@ -246,15 +241,15 @@ LockTableInit(char *tabName,
 	shmemName = (char *) palloc((unsigned) (strlen(tabName) + 32));
 	if (!shmemName)
 	{
-		elog(NOTICE, "LockTableInit: couldn't malloc string %s \n", tabName);
+		elog(NOTICE, "LockMethodTableInit: couldn't malloc string %s \n", tabName);
 		return (INVALID_TABLEID);
 	}
 
 	/* each lock table has a non-shared header */
-	ltable = (LOCKTAB *) palloc((unsigned) sizeof(LOCKTAB));
-	if (!ltable)
+	lockMethodTable = (LOCKMETHODTABLE *) palloc((unsigned) sizeof(LOCKMETHODTABLE));
+	if (!lockMethodTable)
 	{
-		elog(NOTICE, "LockTableInit: couldn't malloc lock table %s\n", tabName);
+		elog(NOTICE, "LockMethodTableInit: couldn't malloc lock table %s\n", tabName);
 		pfree(shmemName);
 		return (INVALID_TABLEID);
 	}
@@ -272,16 +267,20 @@ LockTableInit(char *tabName,
 	 * -----------------------
 	 */
 	sprintf(shmemName, "%s (ctl)", tabName);
-	ltable->ctl = (LOCKCTL *)
-		ShmemInitStruct(shmemName, (unsigned) sizeof(LOCKCTL), &found);
+	lockMethodTable->ctl = (LOCKMETHODCTL *)
+		ShmemInitStruct(shmemName, (unsigned) sizeof(LOCKMETHODCTL), &found);
 
-	if (!ltable->ctl)
+	if (!lockMethodTable->ctl)
 	{
-		elog(FATAL, "LockTableInit: couldn't initialize %s", tabName);
+		elog(FATAL, "LockMethodTableInit: couldn't initialize %s", tabName);
 		status = FALSE;
 	}
 
-	NumTables = 1;
+	/* -------------------
+	 * no zero-th table
+	 * -------------------
+	 */
+	NumLockMethods = 1;
 
 	/* ----------------
 	 * we're first - initialize
@@ -289,18 +288,18 @@ LockTableInit(char *tabName,
 	 */
 	if (!found)
 	{
-		MemSet(ltable->ctl, 0, sizeof(LOCKCTL));
-		ltable->ctl->masterLock = LockMgrLock;
-		ltable->ctl->tableId = NumTables;
+		MemSet(lockMethodTable->ctl, 0, sizeof(LOCKMETHODCTL));
+		lockMethodTable->ctl->masterLock = LockMgrLock;
+		lockMethodTable->ctl->lockmethod = NumLockMethods;
 	}
 
 	/* --------------------
-	 * other modules refer to the lock table by a tableId
+	 * other modules refer to the lock table by a lockmethod
 	 * --------------------
 	 */
-	AllTables[NumTables] = ltable;
-	NumTables++;
-	Assert(NumTables <= MAX_TABLES);
+	LockMethodTable[NumLockMethods] = lockMethodTable;
+	NumLockMethods++;
+	Assert(NumLockMethods <= MAX_LOCK_METHODS);
 
 	/* ----------------------
 	 * allocate a hash table for the lock tags.  This is used
@@ -313,14 +312,14 @@ LockTableInit(char *tabName,
 	hash_flags = (HASH_ELEM | HASH_FUNCTION);
 
 	sprintf(shmemName, "%s (lock hash)", tabName);
-	ltable->lockHash = (HTAB *) ShmemInitHash(shmemName,
+	lockMethodTable->lockHash = (HTAB *) ShmemInitHash(shmemName,
 										 INIT_TABLE_SIZE, MAX_TABLE_SIZE,
 											  &info, hash_flags);
 
-	Assert(ltable->lockHash->hash == tag_hash);
-	if (!ltable->lockHash)
+	Assert(lockMethodTable->lockHash->hash == tag_hash);
+	if (!lockMethodTable->lockHash)
 	{
-		elog(FATAL, "LockTableInit: couldn't initialize %s", tabName);
+		elog(FATAL, "LockMethodTableInit: couldn't initialize %s", tabName);
 		status = FALSE;
 	}
 
@@ -335,31 +334,31 @@ LockTableInit(char *tabName,
 	hash_flags = (HASH_ELEM | HASH_FUNCTION);
 
 	sprintf(shmemName, "%s (xid hash)", tabName);
-	ltable->xidHash = (HTAB *) ShmemInitHash(shmemName,
+	lockMethodTable->xidHash = (HTAB *) ShmemInitHash(shmemName,
 										 INIT_TABLE_SIZE, MAX_TABLE_SIZE,
 											 &info, hash_flags);
 
-	if (!ltable->xidHash)
+	if (!lockMethodTable->xidHash)
 	{
-		elog(FATAL, "LockTableInit: couldn't initialize %s", tabName);
+		elog(FATAL, "LockMethodTableInit: couldn't initialize %s", tabName);
 		status = FALSE;
 	}
 
 	/* init ctl data structures */
-	LockTypeInit(ltable, conflictsP, prioP, ntypes);
+	LockMethodInit(lockMethodTable, conflictsP, prioP, numModes);
 
 	SpinRelease(LockMgrLock);
 
 	pfree(shmemName);
 
 	if (status)
-		return (ltable->ctl->tableId);
+		return (lockMethodTable->ctl->lockmethod);
 	else
 		return (INVALID_TABLEID);
 }
 
 /*
- * LockTableRename -- allocate another tableId to the same
+ * LockMethodTableRename -- allocate another lockmethod to the same
  *		lock table.
  *
  * NOTES: Both the lock module and the lock chain (lchain.c)
@@ -367,28 +366,27 @@ LockTableInit(char *tabName,
  *		kinds of locks.  Short term and long term locks look
  *		the same to the lock table, but are handled differently
  *		by the lock chain manager.	This function allows the
- *		client to use different tableIds when acquiring/releasing
+ *		client to use different lockmethods when acquiring/releasing
  *		short term and long term locks.
  */
 #ifdef NOT_USED
-LockTableId
-LockTableRename(LockTableId tableId)
+LOCKMETHOD
+LockMethodTableRename(LOCKMETHOD lockmethod)
 {
-	LockTableId newTableId;
+	LOCKMETHOD newLockMethod;
 
-	if (NumTables >= MAX_TABLES)
+	if (NumLockMethods >= MAX_LOCK_METHODS)
 		return (INVALID_TABLEID);
-	if (AllTables[tableId] == INVALID_TABLEID)
+	if (LockMethodTable[lockmethod] == INVALID_TABLEID)
 		return (INVALID_TABLEID);
 
-	/* other modules refer to the lock table by a tableId */
-	newTableId = NumTables;
-	NumTables++;
+	/* other modules refer to the lock table by a lockmethod */
+	newLockMethod = NumLockMethods;
+	NumLockMethods++;
 
-	AllTables[newTableId] = AllTables[tableId];
-	return (newTableId);
+	LockMethodTable[newLockMethod] = LockMethodTable[lockmethod];
+	return (newLockMethod);
 }
-
 #endif
 
 /*
@@ -423,13 +421,13 @@ LockTableRename(LockTableId tableId)
  *		acquired if already held by another process.  They must be
  *		released explicitly by the application but they are released
  *		automatically when a backend terminates.
- *		They are indicated by a dummy tableId 0 which doesn't have
+ *		They are indicated by a dummy lockmethod 0 which doesn't have
  *		any table allocated but uses the normal lock table, and are
  *		distinguished from normal locks for the following differences:
  *
  *										normal lock		user lock
  *
- *		tableId							1				0
+ *		lockmethod						1				0
  *		tag.relId						rel oid			0
  *		tag.ItemPointerData.ip_blkid	block id		lock id2
  *		tag.ItemPointerData.ip_posid	tuple offset	lock id1
@@ -437,7 +435,7 @@ LockTableRename(LockTableId tableId)
  *		xid.xid							current xid		0
  *		persistence						transaction		user or backend
  *
- *		The locktype parameter can have the same values for normal locks
+ *		The lockmode parameter can have the same values for normal locks
  *		although probably only WRITE_LOCK can have some practical use.
  *
  *														DZ - 4 Oct 1996
@@ -445,7 +443,7 @@ LockTableRename(LockTableId tableId)
  */
 
 bool
-LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
+LockAcquire(LOCKMETHOD lockmethod, LOCKTAG *locktag, LOCKMODE lockmode)
 {
 	XIDLookupEnt *result,
 				item;
@@ -453,50 +451,50 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 	bool		found;
 	LOCK	   *lock = NULL;
 	SPINLOCK	masterLock;
-	LOCKTAB    *ltable;
+	LOCKMETHODTABLE    *lockMethodTable;
 	int			status;
 	TransactionId myXid;
 
 #ifdef USER_LOCKS
 	int			is_user_lock;
 
-	is_user_lock = (tableId == 0);
+	is_user_lock = (lockmethod == 0);
 	if (is_user_lock)
 	{
-		tableId = 1;
+		lockmethod = 1;
 #ifdef USER_LOCKS_DEBUG
 		elog(NOTICE, "LockAcquire: user lock tag [%u,%u] %d",
-			 lockName->tupleId.ip_posid,
-			 ((lockName->tupleId.ip_blkid.bi_hi << 16) +
-			  lockName->tupleId.ip_blkid.bi_lo),
-			 locktype);
+			 locktag->tupleId.ip_posid,
+			 ((locktag->tupleId.ip_blkid.bi_hi << 16) +
+			  locktag->tupleId.ip_blkid.bi_lo),
+			 lockmode);
 #endif
 	}
 #endif
 
-	Assert(tableId < NumTables);
-	ltable = AllTables[tableId];
-	if (!ltable)
+	Assert(lockmethod < NumLockMethods);
+	lockMethodTable = LockMethodTable[lockmethod];
+	if (!lockMethodTable)
 	{
-		elog(NOTICE, "LockAcquire: bad lock table %d", tableId);
+		elog(NOTICE, "LockAcquire: bad lock table %d", lockmethod);
 		return (FALSE);
 	}
 
 	if (LockingIsDisabled)
 		return (TRUE);
 
-	LOCK_PRINT("Acquire", lockName, locktype);
-	masterLock = ltable->ctl->masterLock;
+	LOCK_PRINT("Acquire", locktag, lockmode);
+	masterLock = lockMethodTable->ctl->masterLock;
 
 	SpinAcquire(masterLock);
 
-	Assert(ltable->lockHash->hash == tag_hash);
-	lock = (LOCK *) hash_search(ltable->lockHash, (Pointer) lockName, HASH_ENTER, &found);
+	Assert(lockMethodTable->lockHash->hash == tag_hash);
+	lock = (LOCK *) hash_search(lockMethodTable->lockHash, (Pointer) locktag, HASH_ENTER, &found);
 
 	if (!lock)
 	{
 		SpinRelease(masterLock);
-		elog(FATAL, "LockAcquire: lock table %d is corrupted", tableId);
+		elog(FATAL, "LockAcquire: lock table %d is corrupted", lockmethod);
 		return (FALSE);
 	}
 
@@ -508,13 +506,13 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 	{
 		lock->mask = 0;
 		ProcQueueInit(&(lock->waitProcs));
-		MemSet((char *) lock->holders, 0, sizeof(int) * MAX_LOCKTYPES);
-		MemSet((char *) lock->activeHolders, 0, sizeof(int) * MAX_LOCKTYPES);
+		MemSet((char *) lock->holders, 0, sizeof(int) * MAX_LOCKMODES);
+		MemSet((char *) lock->activeHolders, 0, sizeof(int) * MAX_LOCKMODES);
 		lock->nHolding = 0;
 		lock->nActive = 0;
 
 		Assert(BlockIdEquals(&(lock->tag.tupleId.ip_blkid),
-							 &(lockName->tupleId.ip_blkid)));
+							 &(locktag->tupleId.ip_blkid)));
 
 	}
 
@@ -523,7 +521,7 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 	 * locks at end of transaction.
 	 * ------------------
 	 */
-	xidTable = ltable->xidHash;
+	xidTable = lockMethodTable->xidHash;
 	myXid = GetCurrentTransactionId();
 
 	/* ------------------
@@ -561,7 +559,7 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 		XID_PRINT("LockAcquire: queueing XidEnt", result);
 		ProcAddLock(&result->queue);
 		result->nHolding = 0;
-		MemSet((char *) result->holders, 0, sizeof(int) * MAX_LOCKTYPES);
+		MemSet((char *) result->holders, 0, sizeof(int) * MAX_LOCKMODES);
 	}
 
 	/* ----------------
@@ -571,7 +569,7 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 	 * ----------------
 	 */
 	lock->nHolding++;
-	lock->holders[locktype]++;
+	lock->holders[lockmode]++;
 
 	/* --------------------
 	 * If I'm the only one holding a lock, then there
@@ -582,19 +580,19 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 	 */
 	if (result->nHolding == lock->nActive)
 	{
-		result->holders[locktype]++;
+		result->holders[lockmode]++;
 		result->nHolding++;
-		GrantLock(lock, locktype);
+		GrantLock(lock, lockmode);
 		SpinRelease(masterLock);
 		return (TRUE);
 	}
 
 	Assert(result->nHolding <= lock->nActive);
 
-	status = LockResolveConflicts(ltable, lock, locktype, myXid);
+	status = LockResolveConflicts(lockmethod, lock, lockmode, myXid);
 
 	if (status == STATUS_OK)
-		GrantLock(lock, locktype);
+		GrantLock(lock, lockmode);
 	else if (status == STATUS_FOUND)
 	{
 #ifdef USER_LOCKS
@@ -611,7 +609,7 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 				hash_search(xidTable, (Pointer) &item, HASH_REMOVE, &found);
 			}
 			lock->nHolding--;
-			lock->holders[locktype]--;
+			lock->holders[lockmode]--;
 			SpinRelease(masterLock);
 #ifdef USER_LOCKS_DEBUG
 			elog(NOTICE, "LockAcquire: user lock failed");
@@ -619,7 +617,7 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 			return (FALSE);
 		}
 #endif
-		status = WaitOnLock(ltable, tableId, lock, locktype);
+		status = WaitOnLock(lockmethod, lock, lockmode);
 		XID_PRINT("Someone granted me the lock", result);
 	}
 
@@ -645,23 +643,23 @@ LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
  * ----------------------------
  */
 int
-LockResolveConflicts(LOCKTAB *ltable,
+LockResolveConflicts(LOCKMETHOD lockmethod,
 					 LOCK *lock,
-					 LOCKTYPE locktype,
+					 LOCKMODE lockmode,
 					 TransactionId xid)
 {
 	XIDLookupEnt *result,
 				item;
 	int		   *myHolders;
-	int			nLockTypes;
+	int			numLockModes;
 	HTAB	   *xidTable;
 	bool		found;
 	int			bitmask;
 	int			i,
 				tmpMask;
 
-	nLockTypes = ltable->ctl->nLockTypes;
-	xidTable = ltable->xidHash;
+	numLockModes = LockMethodTable[lockmethod]->ctl->numLockModes;
+	xidTable = LockMethodTable[lockmethod]->xidHash;
 
 	/* ---------------------
 	 * read my own statistics from the xid table.  If there
@@ -693,7 +691,7 @@ LockResolveConflicts(LOCKTAB *ltable,
 		 * the lock stats.
 		 * ---------------
 		 */
-		MemSet(result->holders, 0, nLockTypes * sizeof(*(lock->holders)));
+		MemSet(result->holders, 0, numLockModes * sizeof(*(lock->holders)));
 		result->nHolding = 0;
 	}
 
@@ -703,7 +701,7 @@ LockResolveConflicts(LOCKTAB *ltable,
 		 * do not continue and share the lock, even if we can.	bjm
 		 * ------------------------
 		 */
-		int			myprio = ltable->ctl->prio[locktype];
+		int			myprio = LockMethodTable[lockmethod]->ctl->prio[lockmode];
 		PROC_QUEUE *waitQueue = &(lock->waitProcs);
 		PROC	   *topproc = (PROC *) MAKE_PTR(waitQueue->links.prev);
 
@@ -716,15 +714,15 @@ LockResolveConflicts(LOCKTAB *ltable,
 	 * with mine, then I get the lock.
 	 *
 	 * Checking for conflict: lock->mask represents the types of
-	 * currently held locks.  conflictTable[locktype] has a bit
+	 * currently held locks.  conflictTable[lockmode] has a bit
 	 * set for each type of lock that conflicts with mine.	Bitwise
 	 * compare tells if there is a conflict.
 	 * ----------------------------
 	 */
-	if (!(ltable->ctl->conflictTab[locktype] & lock->mask))
+	if (!(LockMethodTable[lockmethod]->ctl->conflictTab[lockmode] & lock->mask))
 	{
 
-		result->holders[locktype]++;
+		result->holders[lockmode]++;
 		result->nHolding++;
 
 		XID_PRINT("Conflict Resolved: updated xid entry stats", result);
@@ -740,7 +738,7 @@ LockResolveConflicts(LOCKTAB *ltable,
 	 */
 	bitmask = 0;
 	tmpMask = 2;
-	for (i = 1; i <= nLockTypes; i++, tmpMask <<= 1)
+	for (i = 1; i <= numLockModes; i++, tmpMask <<= 1)
 	{
 		if (lock->activeHolders[i] != myHolders[i])
 			bitmask |= tmpMask;
@@ -753,12 +751,12 @@ LockResolveConflicts(LOCKTAB *ltable,
 	 * conflict and I have to sleep.
 	 * ------------------------
 	 */
-	if (!(ltable->ctl->conflictTab[locktype] & bitmask))
+	if (!(LockMethodTable[lockmethod]->ctl->conflictTab[lockmode] & bitmask))
 	{
 
 		/* no conflict. Get the lock and go on */
 
-		result->holders[locktype]++;
+		result->holders[lockmode]++;
 		result->nHolding++;
 
 		XID_PRINT("Conflict Resolved: updated xid entry stats", result);
@@ -771,11 +769,13 @@ LockResolveConflicts(LOCKTAB *ltable,
 }
 
 static int
-WaitOnLock(LOCKTAB *ltable, LockTableId tableId, LOCK *lock, LOCKTYPE locktype)
+WaitOnLock(LOCKMETHOD lockmethod, LOCK *lock, LOCKMODE lockmode)
 {
 	PROC_QUEUE *waitQueue = &(lock->waitProcs);
+	LOCKMETHODTABLE    *lockMethodTable = LockMethodTable[lockmethod];
+	int			prio = lockMethodTable->ctl->prio[lockmode];
 
-	int			prio = ltable->ctl->prio[locktype];
+	Assert(lockmethod < NumLockMethods);
 
 	/*
 	 * the waitqueue is ordered by priority. I insert myself according to
@@ -785,10 +785,10 @@ WaitOnLock(LOCKTAB *ltable, LockTableId tableId, LOCK *lock, LOCKTYPE locktype)
 	 * synchronization for this queue.	That will not be true if/when
 	 * people can be deleted from the queue by a SIGINT or something.
 	 */
-	LOCK_DUMP_AUX("WaitOnLock: sleeping on lock", lock, locktype);
+	LOCK_DUMP_AUX("WaitOnLock: sleeping on lock", lock, lockmode);
 	if (ProcSleep(waitQueue,
-				  ltable->ctl->masterLock,
-				  locktype,
+				  lockMethodTable->ctl->masterLock,
+				  lockmode,
 				  prio,
 				  lock) != NO_ERROR)
 	{
@@ -799,18 +799,18 @@ WaitOnLock(LOCKTAB *ltable, LockTableId tableId, LOCK *lock, LOCKTYPE locktype)
 		 * -------------------
 		 */
 		lock->nHolding--;
-		lock->holders[locktype]--;
-		LOCK_DUMP_AUX("WaitOnLock: aborting on lock", lock, locktype);
-		SpinRelease(ltable->ctl->masterLock);
+		lock->holders[lockmode]--;
+		LOCK_DUMP_AUX("WaitOnLock: aborting on lock", lock, lockmode);
+		SpinRelease(lockMethodTable->ctl->masterLock);
 		elog(ERROR, "WaitOnLock: error on wakeup - Aborting this transaction");
 	}
 
-	LOCK_DUMP_AUX("WaitOnLock: wakeup on lock", lock, locktype);
+	LOCK_DUMP_AUX("WaitOnLock: wakeup on lock", lock, lockmode);
 	return (STATUS_OK);
 }
 
 /*
- * LockRelease -- look up 'lockName' in lock table 'tableId' and
+ * LockRelease -- look up 'locktag' in lock table 'lockmethod' and
  *		release it.
  *
  * Side Effects: if the lock no longer conflicts with the highest
@@ -820,12 +820,12 @@ WaitOnLock(LOCKTAB *ltable, LockTableId tableId, LOCK *lock, LOCKTYPE locktype)
  *		come along and request the lock).
  */
 bool
-LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
+LockRelease(LOCKMETHOD lockmethod, LOCKTAG *locktag, LOCKMODE lockmode)
 {
 	LOCK	   *lock = NULL;
 	SPINLOCK	masterLock;
 	bool		found;
-	LOCKTAB    *ltable;
+	LOCKMETHODTABLE    *lockMethodTable;
 	XIDLookupEnt *result,
 				item;
 	HTAB	   *xidTable;
@@ -834,41 +834,41 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 #ifdef USER_LOCKS
 	int			is_user_lock;
 
-	is_user_lock = (tableId == 0);
+	is_user_lock = (lockmethod == 0);
 	if (is_user_lock)
 	{
-		tableId = 1;
+		lockmethod = 1;
 #ifdef USER_LOCKS_DEBUG
 		elog(NOTICE, "LockRelease: user lock tag [%u,%u] %d",
-			 lockName->tupleId.ip_posid,
-			 ((lockName->tupleId.ip_blkid.bi_hi << 16) +
-			  lockName->tupleId.ip_blkid.bi_lo),
-			 locktype);
+			 locktag->tupleId.ip_posid,
+			 ((locktag->tupleId.ip_blkid.bi_hi << 16) +
+			  locktag->tupleId.ip_blkid.bi_lo),
+			 lockmode);
 #endif
 	}
 #endif
 
-	Assert(tableId < NumTables);
-	ltable = AllTables[tableId];
-	if (!ltable)
+	Assert(lockmethod < NumLockMethods);
+	lockMethodTable = LockMethodTable[lockmethod];
+	if (!lockMethodTable)
 	{
-		elog(NOTICE, "ltable is null in LockRelease");
+		elog(NOTICE, "lockMethodTable is null in LockRelease");
 		return (FALSE);
 	}
 
 	if (LockingIsDisabled)
 		return (TRUE);
 
-	LOCK_PRINT("Release", lockName, locktype);
+	LOCK_PRINT("Release", locktag, lockmode);
 
-	masterLock = ltable->ctl->masterLock;
-	xidTable = ltable->xidHash;
+	masterLock = lockMethodTable->ctl->masterLock;
+	xidTable = lockMethodTable->xidHash;
 
 	SpinAcquire(masterLock);
 
-	Assert(ltable->lockHash->hash == tag_hash);
+	Assert(lockMethodTable->lockHash->hash == tag_hash);
 	lock = (LOCK *)
-		hash_search(ltable->lockHash, (Pointer) lockName, HASH_FIND_SAVE, &found);
+		hash_search(lockMethodTable->lockHash, (Pointer) locktag, HASH_FIND_SAVE, &found);
 
 #ifdef USER_LOCKS
 
@@ -919,9 +919,9 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 		 * fix the general lock stats
 		 */
 		lock->nHolding--;
-		lock->holders[locktype]--;
+		lock->holders[lockmode]--;
 		lock->nActive--;
-		lock->activeHolders[locktype]--;
+		lock->activeHolders[lockmode]--;
 
 		Assert(lock->nActive >= 0);
 
@@ -933,8 +933,8 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 			 * Delete it from the lock table.
 			 * ------------------
 			 */
-			Assert(ltable->lockHash->hash == tag_hash);
-			lock = (LOCK *) hash_search(ltable->lockHash,
+			Assert(lockMethodTable->lockHash->hash == tag_hash);
+			lock = (LOCK *) hash_search(lockMethodTable->lockHash,
 										(Pointer) &(lock->tag),
 										HASH_REMOVE_SAVED,
 										&found);
@@ -992,7 +992,7 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 	 * now check to see if I have any private locks.  If I do, decrement
 	 * the counts associated with them.
 	 */
-	result->holders[locktype]--;
+	result->holders[lockmode]--;
 	result->nHolding--;
 
 	XID_PRINT("LockRelease updated xid stats", result);
@@ -1038,9 +1038,9 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 		 * fix the general lock stats
 		 */
 		lock->nHolding--;
-		lock->holders[locktype]--;
+		lock->holders[lockmode]--;
 		lock->nActive--;
-		lock->activeHolders[locktype]--;
+		lock->activeHolders[lockmode]--;
 
 		Assert(lock->nActive >= 0);
 
@@ -1052,8 +1052,8 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 			 * Delete it from the lock table.
 			 * ------------------
 			 */
-			Assert(ltable->lockHash->hash == tag_hash);
-			lock = (LOCK *) hash_search(ltable->lockHash,
+			Assert(lockMethodTable->lockHash->hash == tag_hash);
+			lock = (LOCK *) hash_search(lockMethodTable->lockHash,
 										(Pointer) &(lock->tag),
 										HASH_REMOVE,
 										&found);
@@ -1069,10 +1069,10 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 	 * with the remaining locks.
 	 * --------------------------
 	 */
-	if (!(lock->activeHolders[locktype]))
+	if (!(lock->activeHolders[lockmode]))
 	{
 		/* change the conflict mask.  No more of this lock type. */
-		lock->mask &= BITS_OFF[locktype];
+		lock->mask &= BITS_OFF[lockmode];
 	}
 
 	if (wakeupNeeded)
@@ -1083,7 +1083,7 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 		 * himself.
 		 * --------------------------
 		 */
-		ProcLockWakeup(&(lock->waitProcs), (char *) ltable, (char *) lock);
+		ProcLockWakeup(&(lock->waitProcs), lockmethod, lock);
 	}
 
 	SpinRelease(masterLock);
@@ -1091,15 +1091,15 @@ LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype)
 }
 
 /*
- * GrantLock -- udpate the lock data structure to show
+ * GrantLock -- update the lock data structure to show
  *		the new lock holder.
  */
 void
-GrantLock(LOCK *lock, LOCKTYPE locktype)
+GrantLock(LOCK *lock, LOCKMODE lockmode)
 {
 	lock->nActive++;
-	lock->activeHolders[locktype]++;
-	lock->mask |= BITS_ON[locktype];
+	lock->activeHolders[lockmode]++;
+	lock->mask |= BITS_ON[lockmode];
 }
 
 #ifdef USER_LOCKS
@@ -1110,12 +1110,12 @@ GrantLock(LOCK *lock, LOCKTYPE locktype)
  *		 same queue of user locks which can't be removed from the
  *		 normal lock queue at the end of a transaction. They must
  *		 however be removed when the backend exits.
- *		 A dummy tableId 0 is used to indicate that we are releasing
+ *		 A dummy lockmethod 0 is used to indicate that we are releasing
  *		 the user locks, from the code added to ProcKill().
  */
 #endif
 bool
-LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue)
+LockReleaseAll(LOCKMETHOD lockmethod, SHM_QUEUE *lockQueue)
 {
 	PROC_QUEUE *waitQueue;
 	int			done;
@@ -1123,9 +1123,9 @@ LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue)
 	XIDLookupEnt *tmp = NULL;
 	SHMEM_OFFSET end = MAKE_OFFSET(lockQueue);
 	SPINLOCK	masterLock;
-	LOCKTAB    *ltable;
+	LOCKMETHODTABLE    *lockMethodTable;
 	int			i,
-				nLockTypes;
+				numLockModes;
 	LOCK	   *lock;
 	bool		found;
 
@@ -1134,21 +1134,21 @@ LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue)
 				count,
 				nskip;
 
-	is_user_lock_table = (tableId == 0);
+	is_user_lock_table = (lockmethod == 0);
 #ifdef USER_LOCKS_DEBUG
-	elog(NOTICE, "LockReleaseAll: tableId=%d, pid=%d", tableId, MyProcPid);
+	elog(NOTICE, "LockReleaseAll: lockmethod=%d, pid=%d", lockmethod, MyProcPid);
 #endif
 	if (is_user_lock_table)
-		tableId = 1;
+		lockmethod = 1;
 #endif
 
-	Assert(tableId < NumTables);
-	ltable = AllTables[tableId];
-	if (!ltable)
+	Assert(lockmethod < NumLockMethods);
+	lockMethodTable = LockMethodTable[lockmethod];
+	if (!lockMethodTable)
 		return (FALSE);
 
-	nLockTypes = ltable->ctl->nLockTypes;
-	masterLock = ltable->ctl->masterLock;
+	numLockModes = lockMethodTable->ctl->numLockModes;
+	masterLock = lockMethodTable->ctl->masterLock;
 
 	if (SHMQueueEmpty(lockQueue))
 		return TRUE;
@@ -1254,7 +1254,7 @@ LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue)
 			lock->nHolding -= xidLook->nHolding;
 			lock->nActive -= xidLook->nHolding;
 			Assert(lock->nActive >= 0);
-			for (i = 1; i <= nLockTypes; i++)
+			for (i = 1; i <= numLockModes; i++)
 			{
 				lock->holders[i] -= xidLook->holders[i];
 				lock->activeHolders[i] -= xidLook->holders[i];
@@ -1278,7 +1278,7 @@ LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue)
 #ifdef USER_LOCKS
 		SHMQueueDelete(&xidLook->queue);
 #endif
-		if ((!hash_search(ltable->xidHash, (Pointer) xidLook, HASH_REMOVE, &found))
+		if ((!hash_search(lockMethodTable->xidHash, (Pointer) xidLook, HASH_REMOVE, &found))
 			|| !found)
 		{
 			SpinRelease(masterLock);
@@ -1294,9 +1294,9 @@ LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue)
 			 * --------------------
 			 */
 
-			Assert(ltable->lockHash->hash == tag_hash);
+			Assert(lockMethodTable->lockHash->hash == tag_hash);
 			lock = (LOCK *)
-				hash_search(ltable->lockHash, (Pointer) &(lock->tag), HASH_REMOVE, &found);
+				hash_search(lockMethodTable->lockHash, (Pointer) &(lock->tag), HASH_REMOVE, &found);
 			if ((!lock) || (!found))
 			{
 				SpinRelease(masterLock);
@@ -1313,7 +1313,7 @@ LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue)
 			 * --------------------
 			 */
 			waitQueue = &(lock->waitProcs);
-			ProcLockWakeup(waitQueue, (char *) ltable, (char *) lock);
+			ProcLockWakeup(waitQueue, lockmethod, lock);
 		}
 
 #ifdef USER_LOCKS
@@ -1352,7 +1352,7 @@ LockShmemSize()
 	nXidSegs = 1 << (int) my_log2((nLockBuckets - 1) / DEF_SEGSIZE + 1);
 
 	size += MAXALIGN(NBACKENDS * sizeof(PROC)); /* each MyProc */
-	size += MAXALIGN(NBACKENDS * sizeof(LOCKCTL));		/* each ltable->ctl */
+	size += MAXALIGN(NBACKENDS * sizeof(LOCKMETHODCTL)); /* each lockMethodTable->ctl */
 	size += MAXALIGN(sizeof(PROC_HDR)); /* ProcGlobal */
 
 	size += MAXALIGN(my_log2(NLOCKENTS) * sizeof(void *));
@@ -1404,7 +1404,7 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check)
 	SHMEM_OFFSET end = MAKE_OFFSET(lockQueue);
 	LOCK	   *lock;
 
-	LOCKTAB    *ltable;
+	LOCKMETHODTABLE    *lockMethodTable;
 	XIDLookupEnt *result,
 				item;
 	HTAB	   *xidTable;
@@ -1420,8 +1420,8 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check)
 		checked_procs[0] = MyProc;
 		nprocs = 1;
 
-		ltable = AllTables[1];
-		xidTable = ltable->xidHash;
+		lockMethodTable = LockMethodTable[1];
+		xidTable = lockMethodTable->xidHash;
 
 		MemSet(&item, 0, XID_TAGSIZE);
 		TransactionIdStore(MyProc->xid, &item.tag.xid);
@@ -1499,8 +1499,8 @@ DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check)
 					Assert(skip_check);
 					Assert(MyProc->prio == 2);
 
-					ltable = AllTables[1];
-					xidTable = ltable->xidHash;
+					lockMethodTable = LockMethodTable[1];
+					xidTable = lockMethodTable->xidHash;
 
 					MemSet(&item, 0, XID_TAGSIZE);
 					TransactionIdStore(proc->xid, &item.tag.xid);
@@ -1575,12 +1575,12 @@ DumpLocks()
 	XIDLookupEnt *tmp = NULL;
 	SHMEM_OFFSET end;
 	SPINLOCK	masterLock;
-	int			nLockTypes;
+	int			numLockModes;
 	LOCK	   *lock;
 
 	count;
-	int			tableId = 1;
-	LOCKTAB    *ltable;
+	int			lockmethod = 1;
+	LOCKMETHODTABLE    *lockMethodTable;
 
 	ShmemPIDLookup(MyProcPid, &location);
 	if (location == INVALID_OFFSET)
@@ -1590,13 +1590,13 @@ DumpLocks()
 		return;
 	lockQueue = &proc->lockQueue;
 
-	Assert(tableId < NumTables);
-	ltable = AllTables[tableId];
-	if (!ltable)
+	Assert(lockmethod < NumLockMethods);
+	lockMethodTable = LockMethodTable[lockmethod];
+	if (!lockMethodTable)
 		return;
 
-	nLockTypes = ltable->ctl->nLockTypes;
-	masterLock = ltable->ctl->masterLock;
+	numLockModes = lockMethodTable->ctl->numLockModes;
+	masterLock = lockMethodTable->ctl->masterLock;
 
 	if (SHMQueueEmpty(lockQueue))
 		return;
diff --git a/src/backend/storage/lmgr/multi.c b/src/backend/storage/lmgr/multi.c
index d63c32615e2..beb6d2fde8b 100644
--- a/src/backend/storage/lmgr/multi.c
+++ b/src/backend/storage/lmgr/multi.c
@@ -12,7 +12,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/multi.c,v 1.18 1998/06/28 21:17:35 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/multi.c,v 1.19 1998/06/30 02:33:31 momjian Exp $
  *
  * NOTES:
  *	 (1) The lock.c module assumes that the caller here is doing
@@ -30,10 +30,10 @@
 #include "miscadmin.h"			/* MyDatabaseId */
 
 static bool
-MultiAcquire(LockTableId tableId, LOCKTAG *tag, LOCKTYPE locktype,
+MultiAcquire(LOCKMETHOD lockmethod, LOCKTAG *tag, LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level);
 static bool
-MultiRelease(LockTableId tableId, LOCKTAG *tag, LOCKTYPE locktype,
+MultiRelease(LOCKMETHOD lockmethod, LOCKTAG *tag, LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level);
 
 /*
@@ -78,25 +78,27 @@ static int	MultiPrios[] = {
  * Lock table identifier for this lock table.  The multi-level
  * lock table is ONE lock table, not three.
  */
-LockTableId MultiTableId = (LockTableId) NULL;
-LockTableId ShortTermTableId = (LockTableId) NULL;
+LOCKMETHOD MultiTableId = (LOCKMETHOD) NULL;
+#ifdef NOT_USED
+LOCKMETHOD ShortTermTableId = (LOCKMETHOD) NULL;
+#endif
 
 /*
  * Create the lock table described by MultiConflicts and Multiprio.
  */
-LockTableId
+LOCKMETHOD
 InitMultiLevelLocks()
 {
-	int			tableId;
+	int			lockmethod;
 
-	tableId = LockTableInit("LockTable", MultiConflicts, MultiPrios, 5);
-	MultiTableId = tableId;
+	lockmethod = LockMethodTableInit("MultiLevelLockTable", MultiConflicts, MultiPrios, 5);
+	MultiTableId = lockmethod;
 	if (!(MultiTableId))
 		elog(ERROR, "InitMultiLocks: couldnt initialize lock table");
 	/* -----------------------
 	 * No short term lock table for now.  -Jeff 15 July 1991
 	 *
-	 * ShortTermTableId = LockTableRename(tableId);
+	 * ShortTermTableId = LockTableRename(lockmethod);
 	 * if (! (ShortTermTableId)) {
 	 *	 elog(ERROR,"InitMultiLocks: couldnt rename lock table");
 	 * }
@@ -111,7 +113,7 @@ InitMultiLevelLocks()
  * Returns: TRUE if the lock can be set, FALSE otherwise.
  */
 bool
-MultiLockReln(LockInfo linfo, LOCKTYPE locktype)
+MultiLockReln(LockInfo linfo, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -122,7 +124,7 @@ MultiLockReln(LockInfo linfo, LOCKTYPE locktype)
 	MemSet(&tag, 0, sizeof(tag));
 	tag.relId = linfo->lRelId.relId;
 	tag.dbId = linfo->lRelId.dbId;
-	return (MultiAcquire(MultiTableId, &tag, locktype, RELN_LEVEL));
+	return (MultiAcquire(MultiTableId, &tag, lockmode, RELN_LEVEL));
 }
 
 /*
@@ -134,7 +136,7 @@ MultiLockReln(LockInfo linfo, LOCKTYPE locktype)
  *		at the page and relation level.
  */
 bool
-MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
+MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -149,14 +151,14 @@ MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
 
 	/* not locking any valid Tuple, just the page */
 	tag.tupleId = *tidPtr;
-	return (MultiAcquire(MultiTableId, &tag, locktype, TUPLE_LEVEL));
+	return (MultiAcquire(MultiTableId, &tag, lockmode, TUPLE_LEVEL));
 }
 
 /*
  * same as above at page level
  */
 bool
-MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
+MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -179,7 +181,7 @@ MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
 	tag.relId = linfo->lRelId.relId;
 	tag.dbId = linfo->lRelId.dbId;
 	BlockIdCopy(&(tag.tupleId.ip_blkid), &(tidPtr->ip_blkid));
-	return (MultiAcquire(MultiTableId, &tag, locktype, PAGE_LEVEL));
+	return (MultiAcquire(MultiTableId, &tag, lockmode, PAGE_LEVEL));
 }
 
 /*
@@ -189,12 +191,12 @@ MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
  * Side Effects:
  */
 static bool
-MultiAcquire(LockTableId tableId,
+MultiAcquire(LOCKMETHOD lockmethod,
 			 LOCKTAG *tag,
-			 LOCKTYPE locktype,
+			 LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level)
 {
-	LOCKTYPE		locks[N_LEVELS];
+	LOCKMODE		locks[N_LEVELS];
 	int			i,
 				status;
 	LOCKTAG		xxTag,
@@ -213,19 +215,19 @@ MultiAcquire(LockTableId tableId,
 	switch (level)
 	{
 		case RELN_LEVEL:
-			locks[0] = locktype;
+			locks[0] = lockmode;
 			locks[1] = NO_LOCK;
 			locks[2] = NO_LOCK;
 			break;
 		case PAGE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode;
 			locks[2] = NO_LOCK;
 			break;
 		case TUPLE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype + INTENT;
-			locks[2] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode + INTENT;
+			locks[2] = lockmode;
 			break;
 		default:
 			elog(ERROR, "MultiAcquire: bad lock level");
@@ -274,7 +276,7 @@ MultiAcquire(LockTableId tableId,
 					break;
 			}
 
-			status = LockAcquire(tableId, tmpTag, locks[i]);
+			status = LockAcquire(lockmethod, tmpTag, locks[i]);
 			if (!status)
 			{
 
@@ -285,7 +287,7 @@ MultiAcquire(LockTableId tableId,
 				 * the last level lock we successfully acquired
 				 */
 				retStatus = FALSE;
-				MultiRelease(tableId, tag, locktype, i);
+				MultiRelease(lockmethod, tag, lockmode, i);
 				/* now leave the loop.	Don't try for any more locks */
 				break;
 			}
@@ -300,7 +302,7 @@ MultiAcquire(LockTableId tableId,
  */
 #ifdef NOT_USED
 bool
-MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
+MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -316,7 +318,7 @@ MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
 	tag.dbId = linfo->lRelId.dbId;
 	BlockIdCopy(&(tag.tupleId.ip_blkid), &(tidPtr->ip_blkid));
 
-	return (MultiRelease(MultiTableId, &tag, locktype, PAGE_LEVEL));
+	return (MultiRelease(MultiTableId, &tag, lockmode, PAGE_LEVEL));
 }
 
 #endif
@@ -326,7 +328,7 @@ MultiReleasePage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype)
  * ------------------
  */
 bool
-MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype)
+MultiReleaseReln(LockInfo linfo, LOCKMODE lockmode)
 {
 	LOCKTAG		tag;
 
@@ -340,7 +342,7 @@ MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype)
 	tag.relId = linfo->lRelId.relId;
 	tag.dbId = linfo->lRelId.dbId;
 
-	return (MultiRelease(MultiTableId, &tag, locktype, RELN_LEVEL));
+	return (MultiRelease(MultiTableId, &tag, lockmode, RELN_LEVEL));
 }
 
 /*
@@ -349,12 +351,12 @@ MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype)
  * Returns: TRUE if successful, FALSE otherwise.
  */
 static bool
-MultiRelease(LockTableId tableId,
+MultiRelease(LOCKMETHOD lockmethod,
 			 LOCKTAG *tag,
-			 LOCKTYPE locktype,
+			 LOCKMODE lockmode,
 			 PG_LOCK_LEVEL level)
 {
-	LOCKTYPE		locks[N_LEVELS];
+	LOCKMODE		locks[N_LEVELS];
 	int			i,
 				status;
 	LOCKTAG		xxTag,
@@ -366,22 +368,22 @@ MultiRelease(LockTableId tableId,
 	switch (level)
 	{
 		case RELN_LEVEL:
-			locks[0] = locktype;
+			locks[0] = lockmode;
 			locks[1] = NO_LOCK;
 			locks[2] = NO_LOCK;
 			break;
 		case PAGE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode;
 			locks[2] = NO_LOCK;
 			break;
 		case TUPLE_LEVEL:
-			locks[0] = locktype + INTENT;
-			locks[1] = locktype + INTENT;
-			locks[2] = locktype;
+			locks[0] = lockmode + INTENT;
+			locks[1] = lockmode + INTENT;
+			locks[2] = lockmode;
 			break;
 		default:
-			elog(ERROR, "MultiRelease: bad locktype");
+			elog(ERROR, "MultiRelease: bad lockmode");
 	}
 
 	/*
@@ -423,7 +425,7 @@ MultiRelease(LockTableId tableId,
 					ItemPointerCopy(&tmpTag->tupleId, &tag->tupleId);
 					break;
 			}
-			status = LockRelease(tableId, tmpTag, locks[i]);
+			status = LockRelease(lockmethod, tmpTag, locks[i]);
 			if (!status)
 				elog(ERROR, "MultiRelease: couldn't release after error");
 		}
diff --git a/src/backend/storage/lmgr/proc.c b/src/backend/storage/lmgr/proc.c
index 9be4f1bb96e..d4e14fb9c4d 100644
--- a/src/backend/storage/lmgr/proc.c
+++ b/src/backend/storage/lmgr/proc.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.38 1998/06/27 15:47:46 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.39 1998/06/30 02:33:32 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -46,7 +46,7 @@
  *		This is so that we can support more backends. (system-wide semaphore
  *		sets run out pretty fast.)				  -ay 4/95
  *
- * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.38 1998/06/27 15:47:46 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/storage/lmgr/proc.c,v 1.39 1998/06/30 02:33:32 momjian Exp $
  */
 #include <sys/time.h>
 #include <unistd.h>
@@ -580,7 +580,7 @@ ProcWakeup(PROC *proc, int errType)
  *		released.
  */
 int
-ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock)
+ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock)
 {
 	PROC	   *proc;
 	int			count;
@@ -590,8 +590,8 @@ ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock)
 
 	proc = (PROC *) MAKE_PTR(queue->links.prev);
 	count = 0;
-	while ((LockResolveConflicts((LOCKTAB *) ltable,
-								 (LOCK *) lock,
+	while ((LockResolveConflicts(lockmethod,
+								 lock,
 								 proc->token,
 								 proc->xid) == STATUS_OK))
 	{
@@ -602,7 +602,7 @@ ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock)
 		 * between the time we release the lock master (spinlock) and the
 		 * time that the awoken process begins executing again.
 		 */
-		GrantLock((LOCK *) lock, proc->token);
+		GrantLock(lock, proc->token);
 		queue->size--;
 
 		/*
diff --git a/src/backend/storage/lmgr/single.c b/src/backend/storage/lmgr/single.c
index ccae34b3d50..d58657b2c33 100644
--- a/src/backend/storage/lmgr/single.c
+++ b/src/backend/storage/lmgr/single.c
@@ -13,7 +13,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/single.c,v 1.6 1998/06/28 21:17:35 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/lmgr/Attic/single.c,v 1.7 1998/06/30 02:33:32 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -32,7 +32,7 @@
  * Returns: TRUE if the lock can be set, FALSE otherwise.
  */
 bool
-SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action)
+SingleLockReln(LockInfo linfo, LOCKMODE lockmode, int action)
 {
 	LOCKTAG		tag;
 
@@ -47,9 +47,9 @@ SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action)
 	tag.tupleId.ip_posid = InvalidOffsetNumber;
 
 	if (action == UNLOCK)
-		return (LockRelease(MultiTableId, &tag, locktype));
+		return (LockRelease(MultiTableId, &tag, lockmode));
 	else
-		return (LockAcquire(MultiTableId, &tag, locktype));
+		return (LockAcquire(MultiTableId, &tag, lockmode));
 }
 
 /*
@@ -63,7 +63,7 @@ SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action)
 bool
 SingleLockPage(LockInfo linfo,
 			   ItemPointer tidPtr,
-			   LOCKTYPE locktype,
+			   LOCKMODE lockmode,
 			   int action)
 {
 	LOCKTAG		tag;
@@ -80,7 +80,7 @@ SingleLockPage(LockInfo linfo,
 
 
 	if (action == UNLOCK)
-		return (LockRelease(MultiTableId, &tag, locktype));
+		return (LockRelease(MultiTableId, &tag, lockmode));
 	else
-		return (LockAcquire(MultiTableId, &tag, locktype));
+		return (LockAcquire(MultiTableId, &tag, lockmode));
 }
diff --git a/src/include/storage/lmgr.h b/src/include/storage/lmgr.h
index e429bb0047a..f0371dc29a2 100644
--- a/src/include/storage/lmgr.h
+++ b/src/include/storage/lmgr.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lmgr.h,v 1.11 1998/06/28 21:17:35 momjian Exp $
+ * $Id: lmgr.h,v 1.12 1998/06/30 02:33:32 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -72,10 +72,10 @@ extern void RelationSetWIntentLock(Relation relation);
 extern void RelationUnsetWIntentLock(Relation relation);
 
 /* single.c */
-extern bool SingleLockReln(LockInfo linfo, LOCKTYPE locktype, int action);
+extern bool SingleLockReln(LockInfo linfo, LOCKMODE lockmode, int action);
 extern bool
 SingleLockPage(LockInfo linfo, ItemPointer tidPtr,
-			   LOCKTYPE locktype, int action);
+			   LOCKMODE lockmode, int action);
 
 /* proc.c */
 extern void InitProcGlobal(IPCKey key);
diff --git a/src/include/storage/lock.h b/src/include/storage/lock.h
index df70507ad18..48ac1ae553d 100644
--- a/src/include/storage/lock.h
+++ b/src/include/storage/lock.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: lock.h,v 1.14 1998/06/28 21:17:35 momjian Exp $
+ * $Id: lock.h,v 1.15 1998/06/30 02:33:33 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -36,26 +36,25 @@ typedef int MASK;
 #define NLOCKS_PER_XACT 40
 #define NLOCKENTS NLOCKS_PER_XACT*NBACKENDS
 
-typedef int LOCK_TYPE;
-typedef int LOCKTYPE;
-typedef int LockTableId;
+typedef int LOCKMODE;
+typedef int LOCKMETHOD;
 
-/* MAX_LOCKTYPES cannot be larger than the bits in MASK */
-#define MAX_LOCKTYPES 6
+/* MAX_LOCKMODES cannot be larger than the bits in MASK */
+#define MAX_LOCKMODES 6
 
 /*
- * MAX_TABLES corresponds to the number of spin locks allocated in
+ * MAX_LOCK_METHODS corresponds to the number of spin locks allocated in
  * CreateSpinLocks() or the number of shared memory locations allocated
  * for lock table spin locks in the case of machines with TAS instructions.
  */
-#define MAX_TABLES 2
+#define MAX_LOCK_METHODS 2
 
 #define INVALID_TABLEID 0
 
 /*typedef struct LOCK LOCK; */
 
 
-typedef struct ltag
+typedef struct LTAG
 {
 	Oid			relId;
 	Oid			dbId;
@@ -67,31 +66,31 @@ typedef struct ltag
 /* This is the control structure for a lock table.	It
  * lives in shared memory:
  *
- * tableID -- the handle used by the lock table's clients to
- *		refer to the table.
+ * lockmethod -- the handle used by the lock table's clients to
+ *		refer to the type of lock table being used.
  *
- * nLockTypes -- number of lock types (READ,WRITE,etc) that
+ * numLockModes -- number of lock types (READ,WRITE,etc) that
  *		are defined on this lock table
  *
  * conflictTab -- this is an array of bitmasks showing lock
  *		type conflicts. conflictTab[i] is a mask with the j-th bit
  *		turned on if lock types i and j conflict.
  *
- * prio -- each locktype has a priority, so, for example, waiting
+ * prio -- each lockmode has a priority, so, for example, waiting
  *		writers can be given priority over readers (to avoid
  *		starvation).
  *
  * masterlock -- synchronizes access to the table
  *
  */
-typedef struct lockctl
+typedef struct LOCKMETHODCTL
 {
-	LockTableId tableId;
-	int			nLockTypes;
-	int			conflictTab[MAX_LOCKTYPES];
-	int			prio[MAX_LOCKTYPES];
+	LOCKMETHOD 	lockmethod;
+	int			numLockModes;
+	int			conflictTab[MAX_LOCKMODES];
+	int			prio[MAX_LOCKMODES];
 	SPINLOCK	masterLock;
-} LOCKCTL;
+} LOCKMETHODCTL;
 
 /*
  * lockHash -- hash table on lock Ids,
@@ -99,12 +98,12 @@ typedef struct lockctl
  *		multiple processes are holding the lock
  * ctl - control structure described above.
  */
-typedef struct ltable
+typedef struct LOCKMETHODTABLE
 {
 	HTAB	   *lockHash;
 	HTAB	   *xidHash;
-	LOCKCTL    *ctl;
-} LOCKTAB;
+	LOCKMETHODCTL    *ctl;
+} LOCKMETHODTABLE;
 
 /* -----------------------
  * A transaction never conflicts with its own locks.  Hence, if
@@ -148,7 +147,7 @@ typedef struct XIDLookupEnt
 	XIDTAG		tag;
 
 	/* data */
-	int			holders[MAX_LOCKTYPES];
+	int			holders[MAX_LOCKMODES];
 	int			nHolding;
 	SHM_QUEUE	queue;
 } XIDLookupEnt;
@@ -156,7 +155,7 @@ typedef struct XIDLookupEnt
 #define XID_TAGSIZE (sizeof(XIDTAG))
 
 /* originally in procq.h */
-typedef struct procQueue
+typedef struct PROC_QUEUE
 {
 	SHM_QUEUE	links;
 	int			size;
@@ -174,7 +173,7 @@ typedef struct procQueue
  *		lock.
  * nHolding -- total locks of all types.
  */
-typedef struct Lock
+typedef struct LOCK
 {
 	/* hash key */
 	LOCKTAG		tag;
@@ -182,18 +181,18 @@ typedef struct Lock
 	/* data */
 	int			mask;
 	PROC_QUEUE	waitProcs;
-	int			holders[MAX_LOCKTYPES];
+	int			holders[MAX_LOCKMODES];
 	int			nHolding;
-	int			activeHolders[MAX_LOCKTYPES];
+	int			activeHolders[MAX_LOCKMODES];
 	int			nActive;
 } LOCK;
 
 #define LockGetLock_nHolders(l) l->nHolders
 
-#define LockDecrWaitHolders(lock, locktype) \
+#define LockDecrWaitHolders(lock, lockmode) \
 ( \
   lock->nHolding--, \
-  lock->holders[locktype]-- \
+  lock->holders[lockmode]-- \
 )
 
 #define LockLockTable() SpinAcquire(LockMgrLock);
@@ -206,16 +205,16 @@ extern SPINLOCK LockMgrLock;
  */
 extern void InitLocks(void);
 extern void LockDisable(int status);
-extern LockTableId
-LockTableInit(char *tabName, MASK *conflictsP, int *prioP,
-			int ntypes);
-extern bool LockAcquire(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype);
+extern LOCKMETHOD
+LockMethodTableInit(char *tabName, MASK *conflictsP, int *prioP,
+			int numModes);
+extern bool LockAcquire(LOCKMETHOD lockmethod, LOCKTAG *locktag, LOCKMODE lockmode);
 extern int
-LockResolveConflicts(LOCKTAB *ltable, LOCK *lock, LOCKTYPE locktype,
+LockResolveConflicts(LOCKMETHOD lockmethod, LOCK *lock, LOCKMODE lockmode,
 					 TransactionId xid);
-extern bool LockRelease(LockTableId tableId, LOCKTAG *lockName, LOCKTYPE locktype);
-extern void GrantLock(LOCK *lock, LOCKTYPE locktype);
-extern bool LockReleaseAll(LockTableId tableId, SHM_QUEUE *lockQueue);
+extern bool LockRelease(LOCKMETHOD lockmethod, LOCKTAG *locktag, LOCKMODE lockmode);
+extern void GrantLock(LOCK *lock, LOCKMODE lockmode);
+extern bool LockReleaseAll(LOCKMETHOD lockmethod, SHM_QUEUE *lockQueue);
 extern int	LockShmemSize(void);
 extern bool LockingDisabled(void);
 extern bool DeadLockCheck(SHM_QUEUE *lockQueue, LOCK *findlock, bool skip_check);
diff --git a/src/include/storage/multilev.h b/src/include/storage/multilev.h
index 2163ffd9644..95091c9f620 100644
--- a/src/include/storage/multilev.h
+++ b/src/include/storage/multilev.h
@@ -7,7 +7,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: multilev.h,v 1.9 1998/06/28 21:17:36 momjian Exp $
+ * $Id: multilev.h,v 1.10 1998/06/30 02:33:33 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -43,16 +43,18 @@ typedef int PG_LOCK_LEVEL;
 
 /* multi.c */
 
-extern LockTableId MultiTableId;
-extern LockTableId ShortTermTableId;
+extern LOCKMETHOD MultiTableId;
+#ifdef NOT_USED
+extern LOCKMETHOD ShortTermTableId;
+#endif
 
 /*
  * function prototypes
  */
-extern LockTableId InitMultiLevelLocks(void);
-extern bool MultiLockReln(LockInfo linfo, LOCKTYPE locktype);
-extern bool MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype);
-extern bool MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKTYPE locktype);
-extern bool MultiReleaseReln(LockInfo linfo, LOCKTYPE locktype);
+extern LOCKMETHOD InitMultiLevelLocks(void);
+extern bool MultiLockReln(LockInfo linfo, LOCKMODE lockmode);
+extern bool MultiLockTuple(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode);
+extern bool MultiLockPage(LockInfo linfo, ItemPointer tidPtr, LOCKMODE lockmode);
+extern bool MultiReleaseReln(LockInfo linfo, LOCKMODE lockmode);
 
 #endif							/* MULTILEV_H */
diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h
index c41df70e897..f809fad7af5 100644
--- a/src/include/storage/proc.h
+++ b/src/include/storage/proc.h
@@ -6,7 +6,7 @@
  *
  * Copyright (c) 1994, Regents of the University of California
  *
- * $Id: proc.h,v 1.11 1998/02/26 04:43:31 momjian Exp $
+ * $Id: proc.h,v 1.12 1998/06/30 02:33:33 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -100,7 +100,7 @@ extern void ProcQueueInit(PROC_QUEUE *queue);
 extern int
 ProcSleep(PROC_QUEUE *queue, SPINLOCK spinlock, int token,
 		  int prio, LOCK *lock);
-extern int	ProcLockWakeup(PROC_QUEUE *queue, char *ltable, char *lock);
+extern int	ProcLockWakeup(PROC_QUEUE *queue, LOCKMETHOD lockmethod, LOCK *lock);
 extern void ProcAddLock(SHM_QUEUE *elem);
 extern void ProcReleaseSpins(PROC *proc);
 extern void ProcFreeAllSemaphores(void);
diff --git a/src/tools/backend/index.html b/src/tools/backend/index.html
index f736439fa02..3f032e081c3 100644
--- a/src/tools/backend/index.html
+++ b/src/tools/backend/index.html
@@ -25,13 +25,13 @@ structure, like
 The query is then identified as a <I>Utility</I> function or a more
 complex query.  A <I>Utility</I> query is processed by a
 query-specific function in <A HREF="../../backend/commands">
-commands.</A> A complex query, like <B>SELECT, UPDATE,</B> and
-<B>DELETE</B> requires much more handling.
+commands.</A> A complex query, like <CODE>SELECT, UPDATE,</CODE> and
+<CODE>DELETE</CODE> requires much more handling.
 <P>
 The parser takes a complex query, and creates a
 <A HREF="../../include/nodes/parsenodes.h">Query</A> structure that
 contains all the elements used by complex queries.  Query.qual holds the
-<B>WHERE</B> clause qualification, which is filled in by
+<CODE>WHERE</CODE> clause qualification, which is filled in by
 <A HREF="../../backend/parser/parse_clause.c">transformWhereClause().</A>
 Each table referenced in the query is represented by a <A
 HREF="../../include/nodes/parsenodes.h"> RangeTableEntry,</A> and they
@@ -39,19 +39,19 @@ are linked together to form the <I>range table</I> of the query, which is
 generated by <A HREF="../../backend/parser/parse_clause.c">
 makeRangeTable().</A>  Query.rtable holds the queries range table.
 <P>
-Certain queries, like <B>SELECT,</B> return columns of data.  Other
-queries, like <B>INSERT</B> and <B>UPDATE,</B> specify the columns
+Certain queries, like <CODE>SELECT,</CODE> return columns of data.  Other
+queries, like <CODE>INSERT</CODE> and <CODE>UPDATE,</CODE> specify the columns
 modified by the query.  These column references are converted to <A
 HREF="../../include/nodes/primnodes.h">Resdom</A> entries, which are
 linked together to make up the <I>target list</I> of the query. The
 target list is stored in Query.targetList, which is generated by
 <A HREF="../../backend/parser/parse_target.c">transformTargetList().</A>
 <P>
-Other query elements, like aggregates(<B>SUM()</B>), <B>GROUP BY,</B>
-<B>ORDER BY</B> are also stored in their own Query fields.
+Other query elements, like aggregates(<CODE>SUM()</CODE>), <CODE>GROUP BY,</CODE>
+<CODE>ORDER BY</CODE> are also stored in their own Query fields.
 <P>
-The next step is for the Query to be modified by any <B>VIEWS</B> or
-<B>RULES</B> that may apply to the query.  This is performed by the <A
+The next step is for the Query to be modified by any <CODE>VIEWS</CODE> or
+<CODE>RULES</CODE> that may apply to the query.  This is performed by the <A
 HREF="../../backend/rewrite">rewrite</A> system.
 <P>
 The <A HREF="../../backend/optimizer">optimizer</A> takes the Query
@@ -60,7 +60,7 @@ HREF="../..//include/nodes/plannodes.h">Plan,</A> which contains the
 operations to be performed to execute the query.  The <A
 HREF="../../backend/optimizer/path">path</A> module determines the best
 table join order and join type of each table in the RangeTable, using
-Query.qual(<B>WHERE</B> clause) to consider optimal index usage.
+Query.qual(<CODE>WHERE</CODE> clause) to consider optimal index usage.
 <P>
 The Plan is then passed to the <A
 HREF="../../backend/executor">executor</A> for execution, and the result
@@ -81,15 +81,25 @@ data/index buffer cache block
 <LI>Shared Buf Lookup Table - lookup of buffer cache block address using
 table name and block number(<A HREF="../../include/storage/buf_internals.h">
 BufferTag</A>)
-<LI><A HREF="../../include/storage/lock.h">LockTable (ctl)</A> - lock table
-structure, specifiying table, lock types, and backends holding or
-waiting on lock
-<LI>LockTable (lock hash) - lookup of LockTable structures using relation,
-database object ids
-<LI>LockTable (xid hash) - lookup of LockTable structures using
-transaction id, LockTable address
+<LI>MultiLevelLockTable (ctl) - <A
+HREF="../../include/storage/lock.h">LOCKCTL</A> control structure for
+each locking method.  Currently, only multi-level locking is used.
+<LI>MultiLevelLockTable (lock hash) - the <A
+HREF="../../include/storage/lock.h">LOCK</A> structure, looked up using
+relation, database object ids(<A
+HREF="../../include/storage/lock.h">LOCKTAG)</A>.  The lock table structure contains the
+lock modes(read, write) and circular linked list of backends (<A
+HREF="../../include/storage/proc.h">PROC</A> structure pointers) waiting
+on the lock.
+<LI>MultiLevelLockTable (xid hash) - lookup of LOCK structure address
+using transaction id, LOCK address.  It is used to quickly check if the
+current transaction already has any locks on a table, rather than having
+to search through all the held locks.  It also stores the modes
+(read/write) of the locks held by the current transaction.  The returned
+<A HREF="../../include/storage/lock.h">XIDLookupEnt</A> structure also
+contains a pointer to the backend's PROC.lockQueue.
 <LI><A HREF="../../include/storage/proc.h">Proc Header</A> - information
-about each backend, including locks held/waiting,  indexed by process id
+about each backend, including locks held/waiting, indexed by process id
 </UL>
 Each data structure is created by calling <A
 HREF="../../backend/storage/ipc/shmem.c">ShmemInitStruct(),</A> and