RFC: listing lock status

Index: src/backend/storage/lmgr/lmgr.c
===================================================================
RCS file: /var/lib/cvs/pgsql/src/backend/storage/lmgr/lmgr.c,v
retrieving revision 1.53
diff -c -r1.53 lmgr.c
*** src/backend/storage/lmgr/lmgr.c	20 Jun 2002 20:29:35 -0000	1.53
--- src/backend/storage/lmgr/lmgr.c	18 Jul 2002 20:27:31 -0000
***************
*** 104,118 ****
  	if (!(LockTableId))
  		elog(ERROR, "InitLockTable: couldn't initialize lock table");
  
- #ifdef USER_LOCKS
- 
  	/*
  	 * Allocate another tableId for long-term locks
  	 */
  	LongTermTableId = LockMethodTableRename(LockTableId);
  	if (!(LongTermTableId))
  		elog(ERROR, "InitLockTable: couldn't rename long-term lock table");
- #endif
  
  	return LockTableId;
  }
--- 104,115 ----
Index: src/backend/storage/lmgr/lock.c
===================================================================
RCS file: /var/lib/cvs/pgsql/src/backend/storage/lmgr/lock.c,v
retrieving revision 1.108
diff -c -r1.108 lock.c
*** src/backend/storage/lmgr/lock.c	20 Jun 2002 20:29:35 -0000	1.108
--- src/backend/storage/lmgr/lock.c	18 Jul 2002 20:27:31 -0000
***************
*** 1053,1063 ****
  	if (!holder)
  	{
  		LWLockRelease(masterLock);
- #ifdef USER_LOCKS
  		if (lockmethod == USER_LOCKMETHOD)
  			elog(WARNING, "LockRelease: no lock with this tag");
  		else
- #endif
  			elog(WARNING, "LockRelease: holder table corrupted");
  		return FALSE;
  	}
--- 1053,1061 ----
***************
*** 1373,1378 ****
--- 1371,1442 ----
  	return size;
  }
  
+ /*
+  * GetLockStatusData - Return a summary of the lock manager's internal
+  * status, for use in a user-level statistical reporting function.
+  *
+  * This function should be passed a pointer to a LockData struct. It fills
+  * the structure with the appropriate information and returns. The goal
+  * is to hold the LockMgrLock for as short a time as possible; thus, the
+  * function simply makes a copy of the necessary data and releases the
+  * lock, allowing the caller to contemplate and format the data for
+  * as long as it pleases.
+  */
+ void
+ GetLockStatusData(LockData *data)
+ {
+ 	HTAB	*holderTable;
+ 	HOLDER	*holder;
+ 	int		 i = 0;
+ 	HASH_SEQ_STATUS seqstat;
+ 
+ 	data->currIdx = 0;
+ 
+ 	LWLockAcquire(LockMgrLock, LW_EXCLUSIVE);
+ 
+ 	holderTable = LockMethodTable[DEFAULT_LOCKMETHOD]->holderHash;
+ 
+ 	data->nelements = holderTable->hctl->nentries;
+ 
+ 	data->holders = (HOLDER **) palloc(sizeof(HOLDER *) * data->nelements);
+ 	data->procs = (PGPROC **) palloc(sizeof(PGPROC *) * data->nelements);
+ 	data->locks = (LOCK **) palloc(sizeof(LOCK *) * data->nelements);
+ 
+ 	hash_seq_init(&seqstat, holderTable);
+ 
+ 	while ( (holder = hash_seq_search(&seqstat)) )
+ 	{
+ 		PGPROC	*proc;
+ 		LOCK	*lock;
+ 
+ 		data->holders[i] = (HOLDER *) palloc(sizeof(HOLDER));
+ 		data->procs[i] = (PGPROC *) palloc(sizeof(PGPROC));
+ 		data->locks[i] = (LOCK *) palloc(sizeof(LOCK));
+ 
+ 		/* Only do a shallow copy */
+ 		memcpy(data->holders[i], holder, sizeof(HOLDER));
+ 
+ 		proc = (PGPROC *) MAKE_PTR(holder->tag.proc);
+ 
+ 		memcpy(data->procs[i], proc, sizeof(PGPROC));
+ 
+ 		lock = (LOCK *) MAKE_PTR(holder->tag.lock);
+ 
+ 		memcpy(data->locks[i], lock, sizeof(LOCK));
+ 
+ 		i++;
+ 	}
+ 
+ 	Assert(i == data->nelements);
+ 
+ 	LWLockRelease(LockMgrLock);
+ }
+ 
+ char *
+ GetLockmodeName(LOCKMODE mode)
+ {
+ 	return lock_mode_names[mode];
+ }
  
  #ifdef LOCK_DEBUG
  /*
Index: src/backend/storage/lmgr/proc.c
===================================================================
RCS file: /var/lib/cvs/pgsql/src/backend/storage/lmgr/proc.c,v
retrieving revision 1.122
diff -c -r1.122 proc.c
*** src/backend/storage/lmgr/proc.c	13 Jul 2002 01:02:14 -0000	1.122
--- src/backend/storage/lmgr/proc.c	18 Jul 2002 20:27:31 -0000
***************
*** 397,406 ****
  	/* Remove from the standard lock table */
  	LockReleaseAll(DEFAULT_LOCKMETHOD, MyProc, true, InvalidTransactionId);
  
- #ifdef USER_LOCKS
  	/* Remove from the user lock table */
  	LockReleaseAll(USER_LOCKMETHOD, MyProc, true, InvalidTransactionId);
- #endif
  
  	SpinLockAcquire(ProcStructLock);
  
--- 397,404 ----
Index: src/backend/tcop/utility.c
===================================================================
RCS file: /var/lib/cvs/pgsql/src/backend/tcop/utility.c,v
retrieving revision 1.163
diff -c -r1.163 utility.c
*** src/backend/tcop/utility.c	18 Jul 2002 16:47:25 -0000	1.163
--- src/backend/tcop/utility.c	18 Jul 2002 20:27:31 -0000
***************
*** 217,224 ****
  			break;
  
  			/*
! 			 * ******************************** portal manipulation ********************************
! 			 *
  			 */
  		case T_ClosePortalStmt:
  			{
--- 217,223 ----
  			break;
  
  			/*
! 			 * ************************* portal manipulation ***************************
  			 */
  		case T_ClosePortalStmt:
  			{
Index: src/backend/utils/adt/Makefile
===================================================================
RCS file: /var/lib/cvs/pgsql/src/backend/utils/adt/Makefile,v
retrieving revision 1.51
diff -c -r1.51 Makefile
*** src/backend/utils/adt/Makefile	4 Oct 2001 04:13:40 -0000	1.51
--- src/backend/utils/adt/Makefile	18 Jul 2002 20:27:31 -0000
***************
*** 17,23 ****
  
  OBJS = acl.o arrayfuncs.o arrayutils.o bool.o cash.o char.o \
  	date.o datetime.o datum.o float.o format_type.o \
! 	geo_ops.o geo_selfuncs.o int.o int8.o like.o \
  	misc.o nabstime.o name.o not_in.o numeric.o numutils.o \
  	oid.o oracle_compat.o \
  	regexp.o regproc.o ruleutils.o selfuncs.o sets.o \
--- 17,23 ----
  
  OBJS = acl.o arrayfuncs.o arrayutils.o bool.o cash.o char.o \
  	date.o datetime.o datum.o float.o format_type.o \
! 	geo_ops.o geo_selfuncs.o int.o int8.o like.o lockfuncs.o \
  	misc.o nabstime.o name.o not_in.o numeric.o numutils.o \
  	oid.o oracle_compat.o \
  	regexp.o regproc.o ruleutils.o selfuncs.o sets.o \
Index: src/backend/utils/adt/lockfuncs.c
===================================================================
RCS file: src/backend/utils/adt/lockfuncs.c
diff -N src/backend/utils/adt/lockfuncs.c
*** /dev/null	1 Jan 1970 00:00:00 -0000
--- src/backend/utils/adt/lockfuncs.c	18 Jul 2002 20:27:31 -0000
***************
*** 0 ****
--- 1,160 ----
+ /*
+  * lockfuncs.c
+  *		Set-returning functions to view the state of locks within the DB.
+  * 
+  * Copyright (c) 2002, PostgreSQL Global Development Group
+  *
+  * IDENTIFICATION
+  *		$Header$
+  */
+ 
+ #include "postgres.h"
+ #include "fmgr.h"
+ #include "funcapi.h"
+ #include "storage/lmgr.h"
+ #include "storage/lock.h"
+ #include "storage/lwlock.h"
+ #include "storage/proc.h"
+ 
+ Datum show_locks_srf(PG_FUNCTION_ARGS);
+ 
+ static int next_lock(int locks[]);
+ 
+ Datum
+ show_locks_srf(PG_FUNCTION_ARGS)
+ {
+ 	FuncCallContext		*funccxt;
+ 	LockData			*lockData;
+ 
+ 	if (SRF_IS_FIRSTCALL())
+ 	{
+ 		TupleDesc	tupdesc;
+ 
+ 		funccxt = SRF_FIRSTCALL_INIT();
+ 
+ 		tupdesc = RelationNameGetTupleDesc("__show_locks_result");
+ 
+ 		funccxt->slot = TupleDescGetSlot(tupdesc);
+ 
+ 		funccxt->attinmeta = TupleDescGetAttInMetadata(tupdesc);
+ 
+ 		/*
+ 		 * Preload all the locking information that we will eventually format
+ 		 * and send out as a result set. This is palloc'ed, but since the
+ 		 * MemoryContext is reset when the SRF finishes, we don't need to
+ 		 * free it ourselves.
+ 		 */
+ 		funccxt->user_fctx = (LockData *) palloc(sizeof(LockData));
+ 
+ 		GetLockStatusData(funccxt->user_fctx);
+ 	}
+ 
+ 	funccxt	= SRF_PERCALL_SETUP();
+ 	lockData = (LockData *) funccxt->user_fctx;
+ 
+ top:
+ 	/* If the list is empty, we're done */
+ 	if (lockData->currIdx >= lockData->nelements)
+ 		SRF_RETURN_DONE(funccxt);
+ 	else
+ 	{
+ 		HOLDER				 *holder;
+ 		LOCK				 *lock;
+ 		PGPROC				 *proc;
+ 		TupleTableSlot		 *slot;
+ 		AttInMetadata		 *metadata;
+ 		HeapTuple			  tuple;
+ 		Datum				  result;
+ 		char				**values;
+ 		LOCKMODE			  mode;
+ 		int					  i;
+ 		int					  currIdx = lockData->currIdx;
+ 
+ #define NUM_ATTRS 5
+ 
+ 		slot		= funccxt->slot;
+ 		metadata	= funccxt->attinmeta;
+ 		holder		= lockData->holders[currIdx];
+ 		lock		= lockData->locks[currIdx];
+ 		proc		= lockData->procs[currIdx];
+ 
+ 		values = (char **) palloc(sizeof(*values) * NUM_ATTRS);
+ 
+ 		for (i = 0; i < NUM_ATTRS; i++)
+ 			values[i] = (char *) palloc(32);
+ 
+ 		/* The OID of the locked relation */
+ 		snprintf(values[0], 16, "%d", lock->tag.relId);
+ 		/* The database the relation is in */
+ 		snprintf(values[1], 16, "%d", lock->tag.dbId);
+ 		/* The PID of the backend holding or waiting for the lock */
+ 		snprintf(values[2], 16, "%d", proc->pid);
+ 
+ 		/*
+ 		 * We need to report both the locks held (i.e. successfully acquired)
+ 		 * by this holder, as well as the locks upon which it is still
+ 		 * waiting, if any. Since a single HOLDER struct may contain
+ 		 * multiple locks, we may need to loop several times before we
+ 		 * advance the array index and continue on.
+ 		 */
+ 		if (holder->nHolding > 0)
+ 		{
+ 			/* Already held locks */
+ 			mode = next_lock(holder->holding);
+ 			holder->holding[mode]--;
+ 			holder->nHolding--;
+ 
+ 			snprintf(values[4], 16, "%c", 't');
+ 		}
+ 		else if (proc->waitLock != NULL)
+ 		{
+ 			/* Lock that is still being waited on */
+ 			mode = proc->waitLockMode;
+ 			proc->waitLock = NULL;
+ 			proc->waitLockMode = NoLock;
+ 
+ 			snprintf(values[4], 16, "%c", 'f');
+ 		}
+ 		else
+ 		{
+ 			/*
+ 			 * Okay, we've displayed all the lock's belonging to this HOLDER,
+ 			 * procede to the next one. (Note: "Go To Statement Considered
+ 			 * Harmful" notwithstanding, GOTO is appropriate here IMHO)
+ 			 */
+ 			pfree(holder);
+ 			pfree(lock);
+ 			pfree(proc);
+ 			lockData->currIdx++;
+ 			goto top;
+ 		}
+ 
+ 		strncpy(values[3], GetLockmodeName(mode), 32);
+ 
+ 		tuple = BuildTupleFromCStrings(metadata, values);
+ 
+ 		result = TupleGetDatum(slot, tuple);
+ 
+ 		/* Cleanup and return next tuple in result set */
+ 		for (i = 0; i < NUM_ATTRS; i++)
+ 			pfree(values[i]);
+ 		pfree(values);
+ 		SRF_RETURN_NEXT(funccxt, result);
+ 	}
+ }
+ 
+ static LOCKMODE
+ next_lock(int locks[])
+ {
+ 	LOCKMODE i;
+ 
+ 	for (i = 0; i < MAX_LOCKMODES; i++)
+ 	{
+ 		if (locks[i] != 0)
+ 			return i;
+ 	}
+ 
+ 	/* No locks found: this should not occur */
+ 	Assert(false);
+ 	return -1;
+ }
Index: src/bin/initdb/initdb.sh
===================================================================
RCS file: /var/lib/cvs/pgsql/src/bin/initdb/initdb.sh,v
retrieving revision 1.160
diff -c -r1.160 initdb.sh
*** src/bin/initdb/initdb.sh	18 Jul 2002 16:47:25 -0000	1.160
--- src/bin/initdb/initdb.sh	18 Jul 2002 20:27:31 -0000
***************
*** 763,770 ****
      FROM pg_class C LEFT JOIN pg_namespace N ON (N.oid = C.relnamespace) \
      WHERE C.relkind = 'v';
  
- -- XXX why does pg_tables include sequences?
- 
  CREATE VIEW pg_tables AS \
      SELECT \
          C.relname AS tablename, \
--- 763,768 ----
***************
*** 969,974 ****
--- 967,985 ----
                      pg_stat_get_db_blocks_hit(D.oid) AS blks_read, \
              pg_stat_get_db_blocks_hit(D.oid) AS blks_hit \
      FROM pg_database D;
+ 
+ CREATE VIEW __show_locks_result AS \
+ 	SELECT \
+ 			''::oid AS relation, \
+ 			''::oid AS database, \
+ 			''::int4 AS backendpid, \
+ 			''::text AS mode, \
+ 			NULL::bool AS isgranted;
+ 
+ UPDATE pg_proc SET \
+ 	prorettype = (SELECT oid FROM pg_type \
+ 		WHERE typname = '__show_locks_result') \
+ 	WHERE proname = 'show_locks';
  
  EOF
  if [ "$?" -ne 0 ]; then
Index: src/include/pg_config.h.in
===================================================================
RCS file: /var/lib/cvs/pgsql/src/include/pg_config.h.in,v
retrieving revision 1.24
diff -c -r1.24 pg_config.h.in
*** src/include/pg_config.h.in	5 May 2002 00:03:29 -0000	1.24
--- src/include/pg_config.h.in	18 Jul 2002 20:27:31 -0000
***************
*** 180,194 ****
  /* #define TCL_ARRAYS */
  
  /*
-  * User locks are handled totally on the application side as long term
-  * cooperative locks which extend beyond the normal transaction boundaries.
-  * Their purpose is to indicate to an application that someone is `working'
-  * on an item.  Define this flag to enable user locks.  You will need the
-  * loadable module user-locks.c to use this feature.
-  */
- #define USER_LOCKS
- 
- /*
   * Define this if you want psql to _always_ ask for a username and a password
   * for password authentication.
   */
--- 180,185 ----
Index: src/include/catalog/catversion.h
===================================================================
RCS file: /var/lib/cvs/pgsql/src/include/catalog/catversion.h,v
retrieving revision 1.140
diff -c -r1.140 catversion.h
*** src/include/catalog/catversion.h	15 Jul 2002 16:33:31 -0000	1.140
--- src/include/catalog/catversion.h	18 Jul 2002 20:27:31 -0000
***************
*** 53,58 ****
   */
  
  /*							yyyymmddN */
! #define CATALOG_VERSION_NO	200207141
  
  #endif
--- 53,58 ----
   */
  
  /*							yyyymmddN */
! #define CATALOG_VERSION_NO	200207181
  
  #endif
Index: src/include/catalog/pg_proc.h
===================================================================
RCS file: /var/lib/cvs/pgsql/src/include/catalog/pg_proc.h,v
retrieving revision 1.243
diff -c -r1.243 pg_proc.h
*** src/include/catalog/pg_proc.h	20 Jun 2002 20:29:44 -0000	1.243
--- src/include/catalog/pg_proc.h	18 Jul 2002 20:27:31 -0000
***************
*** 2681,2686 ****
--- 2681,2689 ----
  DATA(insert OID = 1915 (  numeric_uplus    PGNSP PGUID 12 f f f t f i 1 1700 "1700" 100 0 0 100  numeric_uplus - _null_ ));
  DESCR("unary plus");
  
+ DATA(insert OID = 1920 (  show_locks	   PGNSP PGUID 12 f f f t t v 0 0 "0" 100 0 0 100 show_locks_srf - _null_ ));
+ DESCR("view system lock information");
+ 
  DATA(insert OID = 1922 (  has_table_privilege		   PGNSP PGUID 12 f f f t f s 3 16 "19 25 25" 100 0 0 100  has_table_privilege_name_name - _null_ ));
  DESCR("user privilege on relation by username, relname");
  DATA(insert OID = 1923 (  has_table_privilege		   PGNSP PGUID 12 f f f t f s 3 16 "19 26 25" 100 0 0 100  has_table_privilege_name_id - _null_ ));
Index: src/include/storage/lock.h
===================================================================
RCS file: /var/lib/cvs/pgsql/src/include/storage/lock.h,v
retrieving revision 1.61
diff -c -r1.61 lock.h
*** src/include/storage/lock.h	20 Jun 2002 20:29:52 -0000	1.61
--- src/include/storage/lock.h	18 Jul 2002 20:27:31 -0000
***************
*** 59,66 ****
  #define USER_LOCKMETHOD		2
  
  /*
!  * There is normally only one lock method, the default one.
!  * If user locks are enabled, an additional lock method is present.
   *
   * LOCKMETHODCTL and LOCKMETHODTABLE are split because the first lives
   * in shared memory.  (There isn't any really good reason for the split.)
--- 59,66 ----
  #define USER_LOCKMETHOD		2
  
  /*
!  * There are currently two lock methods: the default method, and the method
!  * used for user locks.
   *
   * LOCKMETHODCTL and LOCKMETHODTABLE are split because the first lives
   * in shared memory.  (There isn't any really good reason for the split.)
***************
*** 222,227 ****
--- 222,242 ----
  #define HOLDER_LOCKMETHOD(holder) \
  		(((LOCK *) MAKE_PTR((holder).tag.lock))->tag.lockmethod)
  
+ /*
+  * This struct is used to encapsulate information passed from lmgr
+  * internals to the lock listing statistical functions (lockfuncs.c).
+  * It's just a convenient bundle of other lock.h structures. All
+  * the information at a given index (holders[i], procs[i], locks[i])
+  * is related.
+  */
+ typedef struct
+ {
+ 	int		  nelements;	/* The length of holders, procs, & locks */
+ 	int		  currIdx;		/* Current element being examined */
+ 	HOLDER	**holders;
+ 	PGPROC	**procs;
+ 	LOCK	**locks;
+ } LockData;
  
  /*
   * function prototypes
***************
*** 246,251 ****
--- 261,268 ----
  extern int	LockShmemSize(int maxBackends);
  extern bool DeadLockCheck(PGPROC *proc);
  extern void InitDeadLockChecking(void);
+ extern void GetLockStatusData(LockData *data);
+ extern char *GetLockmodeName(LOCKMODE mode);
  
  #ifdef LOCK_DEBUG
  extern void DumpLocks(void);
Index: src/include/storage/shmem.h
===================================================================
RCS file: /var/lib/cvs/pgsql/src/include/storage/shmem.h,v
retrieving revision 1.37
diff -c -r1.37 shmem.h
*** src/include/storage/shmem.h	20 Jun 2002 20:29:52 -0000	1.37
--- src/include/storage/shmem.h	18 Jul 2002 20:27:31 -0000
***************
*** 53,60 ****
  #define SHM_OFFSET_VALID(xx_offs)\
    (((xx_offs) != 0) && ((xx_offs) != INVALID_OFFSET))
  
! 
! /* shmemqueue.c */
  typedef struct SHM_QUEUE
  {
  	SHMEM_OFFSET prev;
--- 53,59 ----
  #define SHM_OFFSET_VALID(xx_offs)\
    (((xx_offs) != 0) && ((xx_offs) != INVALID_OFFSET))
  
! /* shmqueue.c */
  typedef struct SHM_QUEUE
  {
  	SHMEM_OFFSET prev;
Index: src/test/regress/expected/rules.out
===================================================================
RCS file: /var/lib/cvs/pgsql/src/test/regress/expected/rules.out,v
retrieving revision 1.53
diff -c -r1.53 rules.out
*** src/test/regress/expected/rules.out	3 May 2002 00:32:19 -0000	1.53
--- src/test/regress/expected/rules.out	18 Jul 2002 20:27:31 -0000
***************
*** 1266,1271 ****
--- 1266,1272 ----
  SELECT viewname, definition FROM pg_views ORDER BY viewname;
           viewname         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           definition                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            
  --------------------------+-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+  __show_locks_result      | SELECT 0::oid AS relation, 0::oid AS "database", 0 AS backendpid, ''::text AS "mode", NULL::boolean AS isgranted;
   iexit                    | SELECT ih.name, ih.thepath, interpt_pp(ih.thepath, r.thepath) AS exit FROM ihighway ih, ramp r WHERE (ih.thepath ## r.thepath);
   pg_indexes               | SELECT c.relname AS tablename, i.relname AS indexname, pg_get_indexdef(x.indexrelid) AS indexdef FROM pg_index x, pg_class c, pg_class i WHERE ((((c.relkind = 'r'::"char") AND (i.relkind = 'i'::"char")) AND (c.oid = x.indrelid)) AND (i.oid = x.indexrelid));
   pg_rules                 | SELECT n.nspname AS schemaname, c.relname AS tablename, r.rulename, pg_get_ruledef(r.oid) AS definition FROM ((pg_rewrite r JOIN pg_class c ON ((c.oid = r.ev_class))) LEFT JOIN pg_namespace n ON ((n.oid = c.relnamespace))) WHERE (r.rulename <> '_RETURN'::name);
***************
*** 1304,1310 ****
   shoelace_obsolete        | SELECT shoelace.sl_name, shoelace.sl_avail, shoelace.sl_color, shoelace.sl_len, shoelace.sl_unit, shoelace.sl_len_cm FROM shoelace WHERE (NOT (EXISTS (SELECT shoe.shoename FROM shoe WHERE (shoe.slcolor = shoelace.sl_color))));
   street                   | SELECT r.name, r.thepath, c.cname FROM ONLY road r, real_city c WHERE (c.outline ## r.thepath);
   toyemp                   | SELECT emp.name, emp.age, emp."location", (12 * emp.salary) AS annualsal FROM emp;
! (38 rows)
  
  SELECT tablename, rulename, definition FROM pg_rules 
  	ORDER BY tablename, rulename;
--- 1305,1311 ----
   shoelace_obsolete        | SELECT shoelace.sl_name, shoelace.sl_avail, shoelace.sl_color, shoelace.sl_len, shoelace.sl_unit, shoelace.sl_len_cm FROM shoelace WHERE (NOT (EXISTS (SELECT shoe.shoename FROM shoe WHERE (shoe.slcolor = shoelace.sl_color))));
   street                   | SELECT r.name, r.thepath, c.cname FROM ONLY road r, real_city c WHERE (c.outline ## r.thepath);
   toyemp                   | SELECT emp.name, emp.age, emp."location", (12 * emp.salary) AS annualsal FROM emp;
! (39 rows)
  
  SELECT tablename, rulename, definition FROM pg_rules 
  	ORDER BY tablename, rulename;