Autovacuum launcher patch

Index: src/backend/access/transam/varsup.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/access/transam/varsup.c,v
retrieving revision 1.77
diff -c -p -r1.77 varsup.c
*** src/backend/access/transam/varsup.c	5 Jan 2007 22:19:23 -0000	1.77
--- src/backend/access/transam/varsup.c	26 Jan 2007 23:13:35 -0000
*************** GetNewTransactionId(bool isSubXact)
*** 72,78 ****
  		 * still gives plenty of chances before we get into real trouble.
  		 */
  		if (IsUnderPostmaster && (xid % 65536) == 0)
! 			SendPostmasterSignal(PMSIGNAL_START_AUTOVAC);
  
  		if (IsUnderPostmaster &&
  		 TransactionIdFollowsOrEquals(xid, ShmemVariableCache->xidStopLimit))
--- 72,78 ----
  		 * still gives plenty of chances before we get into real trouble.
  		 */
  		if (IsUnderPostmaster && (xid % 65536) == 0)
! 			SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER);
  
  		if (IsUnderPostmaster &&
  		 TransactionIdFollowsOrEquals(xid, ShmemVariableCache->xidStopLimit))
*************** SetTransactionIdLimit(TransactionId olde
*** 286,292 ****
  	 */
  	if (TransactionIdFollowsOrEquals(curXid, xidVacLimit) &&
  		IsUnderPostmaster)
! 		SendPostmasterSignal(PMSIGNAL_START_AUTOVAC);
  
  	/* Give an immediate warning if past the wrap warn point */
  	if (TransactionIdFollowsOrEquals(curXid, xidWarnLimit))
--- 286,292 ----
  	 */
  	if (TransactionIdFollowsOrEquals(curXid, xidVacLimit) &&
  		IsUnderPostmaster)
! 		SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER);
  
  	/* Give an immediate warning if past the wrap warn point */
  	if (TransactionIdFollowsOrEquals(curXid, xidWarnLimit))
Index: src/backend/commands/vacuum.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/commands/vacuum.c,v
retrieving revision 1.343
diff -c -p -r1.343 vacuum.c
*** src/backend/commands/vacuum.c	5 Jan 2007 22:19:26 -0000	1.343
--- src/backend/commands/vacuum.c	26 Jan 2007 17:23:00 -0000
*************** vacuum(VacuumStmt *vacstmt, List *relids
*** 303,309 ****
  	 * Send info about dead objects to the statistics collector, unless we are
  	 * in autovacuum --- autovacuum.c does this for itself.
  	 */
! 	if (vacstmt->vacuum && !IsAutoVacuumProcess())
  		pgstat_vacuum_tabstat();
  
  	/*
--- 303,309 ----
  	 * Send info about dead objects to the statistics collector, unless we are
  	 * in autovacuum --- autovacuum.c does this for itself.
  	 */
! 	if (vacstmt->vacuum && !IsAutoVacuumWorkerProcess())
  		pgstat_vacuum_tabstat();
  
  	/*
*************** vacuum(VacuumStmt *vacstmt, List *relids
*** 472,478 ****
  		ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
  	}
  
! 	if (vacstmt->vacuum && !IsAutoVacuumProcess())
  	{
  		/*
  		 * Update pg_database.datfrozenxid, and truncate pg_clog if possible.
--- 472,478 ----
  		ActiveSnapshot = CopySnapshot(GetTransactionSnapshot());
  	}
  
! 	if (vacstmt->vacuum && !IsAutoVacuumWorkerProcess())
  	{
  		/*
  		 * Update pg_database.datfrozenxid, and truncate pg_clog if possible.
Index: src/backend/postmaster/autovacuum.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/postmaster/autovacuum.c,v
retrieving revision 1.31
diff -c -p -r1.31 autovacuum.c
*** src/backend/postmaster/autovacuum.c	16 Jan 2007 13:28:56 -0000	1.31
--- src/backend/postmaster/autovacuum.c	26 Jan 2007 23:07:29 -0000
***************
*** 39,45 ****
--- 39,47 ----
  #include "postmaster/postmaster.h"
  #include "storage/fd.h"
  #include "storage/ipc.h"
+ #include "storage/pmsignal.h"
  #include "storage/proc.h"
+ #include "storage/procarray.h"
  #include "storage/sinval.h"
  #include "tcop/tcopprot.h"
  #include "utils/flatfiles.h"
***************
*** 50,55 ****
--- 52,59 ----
  #include "utils/syscache.h"
  
  
+ static bool avlauncher_exit_request = false;
+ 
  /*
   * GUC parameters
   */
*************** int			autovacuum_vac_cost_delay;
*** 65,71 ****
  int			autovacuum_vac_cost_limit;
  
  /* Flag to tell if we are in the autovacuum daemon process */
! static bool am_autovacuum = false;
  
  /* Last time autovac daemon started/stopped (only valid in postmaster) */
  static time_t last_autovac_start_time = 0;
--- 69,76 ----
  int			autovacuum_vac_cost_limit;
  
  /* Flag to tell if we are in the autovacuum daemon process */
! static bool am_autovacuum_launcher = false;
! static bool am_autovacuum_worker = false;
  
  /* Last time autovac daemon started/stopped (only valid in postmaster) */
  static time_t last_autovac_start_time = 0;
*************** static int	default_freeze_min_age;
*** 80,85 ****
--- 85,93 ----
  /* Memory context for long-lived data */
  static MemoryContext AutovacMemCxt;
  
+ /* Memory context for stat data */
+ static MemoryContext AutoVacStatContext;
+ 
  /* struct to keep list of candidate databases for vacuum */
  typedef struct autovac_dbase
  {
*************** typedef struct autovac_table
*** 101,113 ****
  	int			vacuum_cost_limit;
  } autovac_table;
  
  
  #ifdef EXEC_BACKEND
! static pid_t autovac_forkexec(void);
  #endif
! NON_EXEC_STATIC void AutoVacMain(int argc, char *argv[]);
  static void do_autovacuum(PgStat_StatDBEntry *dbentry);
  static List *autovac_get_database_list(void);
  static void test_rel_for_autovac(Oid relid, PgStat_StatTabEntry *tabentry,
  					 Form_pg_class classForm,
  					 Form_pg_autovacuum avForm,
--- 109,133 ----
  	int			vacuum_cost_limit;
  } autovac_table;
  
+ typedef struct
+ {
+ 	Oid		process_db;			/* OID of database to process */
+ 	int		worker_pid;			/* PID of the worker process, if any */
+ } AutoVacuumShmemStruct;
+ 
+ static AutoVacuumShmemStruct *AutoVacuumShmem;
+ 
  
  #ifdef EXEC_BACKEND
! static pid_t avlauncher_forkexec(void);
! static pid_t avworker_forkexec(void);
  #endif
! NON_EXEC_STATIC void AutoVacWorkerMain(int argc, char *argv[]);
! NON_EXEC_STATIC void AutoVacLauncherMain(int argc, char *argv[]);
! 
  static void do_autovacuum(PgStat_StatDBEntry *dbentry);
  static List *autovac_get_database_list(void);
+ static char *autovac_get_database_name(Oid dbid);
  static void test_rel_for_autovac(Oid relid, PgStat_StatTabEntry *tabentry,
  					 Form_pg_class classForm,
  					 Form_pg_autovacuum avForm,
*************** static void test_rel_for_autovac(Oid rel
*** 116,130 ****
  static void autovacuum_do_vac_analyze(Oid relid, bool dovacuum,
  						  bool doanalyze, int freeze_min_age);
  static void autovac_report_activity(VacuumStmt *vacstmt, Oid relid);
  
  
  /*
!  * Main entry point for autovacuum controller process.
   *
!  * This code is heavily based on pgarch.c, q.v.
   */
  int
! autovac_start(void)
  {
  	time_t		curtime;
  	pid_t		AutoVacPID;
--- 136,188 ----
  static void autovacuum_do_vac_analyze(Oid relid, bool dovacuum,
  						  bool doanalyze, int freeze_min_age);
  static void autovac_report_activity(VacuumStmt *vacstmt, Oid relid);
+ static void avlauncher_exit(SIGNAL_ARGS);
+ static void avl_quickdie(SIGNAL_ARGS);
+ 
+ 
  
+ /********************************************************************
+  *                    AUTOVACUUM LAUNCHER CODE
+  ********************************************************************/
  
+ #ifdef EXEC_BACKEND
  /*
!  * forkexec routine for the autovacuum launcher process.
   *
!  * Format up the arglist, then fork and exec.
!  */
! static pid_t
! avlauncher_forkexec(void)
! {
! 	char	   *av[10];
! 	int			ac = 0;
! 
! 	av[ac++] = "postgres";
! 	av[ac++] = "--forkavlauncher";
! 	av[ac++] = NULL;			/* filled in by postmaster_forkexec */
! 	av[ac] = NULL;
! 
! 	Assert(ac < lengthof(av));
! 
! 	return postmaster_forkexec(ac, av);
! }
! 
! /*
!  * We need this set from the outside, before InitProcess is called
!  */
! void
! AutovacuumLauncherIAm(void)
! {
! 	am_autovacuum_launcher = true;
! }
! #endif
! 
! /*
!  * Main entry point for autovacuum launcher process, to be called from the
!  * postmaster.
   */
  int
! StartAutoVacLauncher(void)
  {
  	time_t		curtime;
  	pid_t		AutoVacPID;
*************** autovac_start(void)
*** 142,147 ****
--- 200,209 ----
  	 * will get another chance later if we do nothing now.
  	 *
  	 * XXX todo: implement sleep scale factor that existed in contrib code.
+ 	 *
+ 	 * FIXME -- figure out how much of this is still relevant.  It's leftover
+ 	 * from before we had a separation between launcher and worker, probably
+ 	 * most of it is obsolete.
  	 */
  
  	curtime = time(NULL);
*************** autovac_start(void)
*** 156,162 ****
  	last_autovac_start_time = curtime;
  
  #ifdef EXEC_BACKEND
! 	switch ((AutoVacPID = autovac_forkexec()))
  #else
  	switch ((AutoVacPID = fork_process()))
  #endif
--- 218,224 ----
  	last_autovac_start_time = curtime;
  
  #ifdef EXEC_BACKEND
! 	switch ((AutoVacPID = avlauncher_forkexec()))
  #else
  	switch ((AutoVacPID = fork_process()))
  #endif
*************** autovac_start(void)
*** 175,181 ****
  			/* Lose the postmaster's on-exit routines */
  			on_exit_reset();
  
! 			AutoVacMain(0, NULL);
  			break;
  #endif
  		default:
--- 237,243 ----
  			/* Lose the postmaster's on-exit routines */
  			on_exit_reset();
  
! 			AutoVacLauncherMain(0, NULL);
  			break;
  #endif
  		default:
*************** autovac_start(void)
*** 187,214 ****
  }
  
  /*
!  * autovac_stopped --- called by postmaster when subprocess exit is detected
   */
! void
! autovac_stopped(void)
  {
! 	last_autovac_stop_time = time(NULL);
  }
  
  #ifdef EXEC_BACKEND
  /*
!  * autovac_forkexec()
   *
!  * Format up the arglist for the autovacuum process, then fork and exec.
   */
  static pid_t
! autovac_forkexec(void)
  {
  	char	   *av[10];
  	int			ac = 0;
  
  	av[ac++] = "postgres";
! 	av[ac++] = "--forkautovac";
  	av[ac++] = NULL;			/* filled in by postmaster_forkexec */
  	av[ac] = NULL;
  
--- 249,596 ----
  }
  
  /*
!  * Main loop for the autovacuum launcher process.
   */
! NON_EXEC_STATIC void
! AutoVacLauncherMain(int argc, char *argv[])
! {
! 	sigjmp_buf	local_sigjmp_buf;
! 	List	   *dblist;
! 	bool		for_xid_wrap;
! 	autovac_dbase *db;
! 	MemoryContext	avlauncher_cxt;
! 
! 	/* we are a postmaster subprocess now */
! 	IsUnderPostmaster = true;
! 	am_autovacuum_launcher = true;
! 
! 	/* reset MyProcPid */
! 	MyProcPid = getpid();
! 
! 	/* Identify myself via ps */
! 	init_ps_display("autovacuum launcher process", "", "", "");
! 
! 	SetProcessingMode(InitProcessing);
! 
! 	/*
! 	 * If possible, make this process a group leader, so that the postmaster
! 	 * can signal any child processes too.  (autovacuum probably never has
! 	 * any child processes, but for consistency we make all postmaster
! 	 * child processes do this.)
! 	 */
! #ifdef HAVE_SETSID
! 	if (setsid() < 0)
! 		elog(FATAL, "setsid() failed: %m");
! #endif
! 
! 	/*
! 	 * Set up signal handlers.	Since this is a "dummy" process, it has
! 	 * particular signal requirements -- no deadlock checker or sinval
! 	 * catchup, for example.
! 	 *
! 	 * Currently, we don't pay attention to postgresql.conf changes that
! 	 * happen during a single daemon iteration, so we can ignore SIGHUP.
! 	 *
! 	 * FIXME -- this was correct for the old autovacuum, but the avlauncher
! 	 * should be paying attention.  Additionally, it may be a good idea to
! 	 * receive signals when an avworker process finishes.
! 	 */
! 	pqsignal(SIGHUP, SIG_IGN);
! 
! 	pqsignal(SIGINT, SIG_IGN);
! 	pqsignal(SIGTERM, avlauncher_exit);
! 	pqsignal(SIGQUIT, avl_quickdie);
! 	pqsignal(SIGALRM, SIG_IGN);
! 
! 	pqsignal(SIGPIPE, SIG_IGN);
! 	pqsignal(SIGUSR1, SIG_IGN);
! 	/* We don't listen for async notifies */
! 	pqsignal(SIGUSR2, SIG_IGN);
! 	pqsignal(SIGFPE, FloatExceptionHandler);
! 	pqsignal(SIGCHLD, SIG_DFL);
! 
! 	/* Early initialization */
! 	BaseInit();
! 
! 	/*
! 	 * Create a per-backend PGPROC struct in shared memory, except in the
! 	 * EXEC_BACKEND case where this was done in SubPostmasterMain. We must do
! 	 * this before we can use LWLocks (and in the EXEC_BACKEND case we already
! 	 * had to do some stuff with LWLocks).
! 	 */
! #ifndef EXEC_BACKEND
! 	InitDummyProcess();
! #endif
! 
! 	/*
! 	 * Create a memory context that we will do all our work in.  We do this so
! 	 * that we can reset the context during error recovery and thereby avoid
! 	 * possible memory leaks.
! 	 */
! 	avlauncher_cxt = AllocSetContextCreate(TopMemoryContext,
! 										   "Autovacuum Launcher",
! 										   ALLOCSET_DEFAULT_MINSIZE,
! 										   ALLOCSET_DEFAULT_INITSIZE,
! 										   ALLOCSET_DEFAULT_MAXSIZE);
! 	MemoryContextSwitchTo(avlauncher_cxt);
! 
! 
! 	/*
! 	 * If an exception is encountered, processing resumes here.
! 	 *
! 	 * This code is heavily based on bgwriter.c, q.v.
! 	 */
! 	if (sigsetjmp(local_sigjmp_buf, 1) != 0)
! 	{
! 		/* since not using PG_TRY, must reset error stack by hand */
! 		error_context_stack = NULL;
! 
! 		/* Prevents interrupts while cleaning up */
! 		HOLD_INTERRUPTS();
! 
! 		/* Report the error to the server log */
! 		EmitErrorReport();
! 
! 		/*
! 		 * These operations are really just a minimal subset of
! 		 * AbortTransaction().  We don't have very many resources to worry
! 		 * about, but we do have LWLocks.
! 		 */
! 		LWLockReleaseAll();
! 		AtEOXact_Files();
! 
! 		/*
! 		 * Now return to normal top-level context and clear ErrorContext for
! 		 * next time.
! 		 */
! 		MemoryContextSwitchTo(avlauncher_cxt);
! 		FlushErrorState();
! 
! 		/* Flush any leaked data in the top-level context */
! 		MemoryContextResetAndDeleteChildren(avlauncher_cxt);
! 		/* Make sure pgstat also considers our stat data as gone */
! 		pgstat_stathash_reset();
! 
! 		/* Now we can allow interrupts again */
! 		RESUME_INTERRUPTS();
! 
! 		/*
! 		 * Sleep at least 1 second after any error.  We don't want to be
! 		 * filling the error logs as fast as we can.
! 		 */
! 		pg_usleep(1000000L);
! 	}
! 
! 	/* We can now handle ereport(ERROR) */
! 	PG_exception_stack = &local_sigjmp_buf;
! 
! 	ereport(LOG,
! 			(errmsg("autovacuum launcher started")));
! 
! 	PG_SETMASK(&UnBlockSig);
! 
! 	AutoVacStatContext = AllocSetContextCreate(avlauncher_cxt,
! 											   "AVLauncher Stat Hash",
! 											   ALLOCSET_DEFAULT_MINSIZE,
! 											   ALLOCSET_DEFAULT_INITSIZE,
! 											   ALLOCSET_DEFAULT_MAXSIZE);
! 
! 	for (;;)
! 	{
! 		TransactionId xidForceLimit;
! 		ListCell *cell;
! 		int		worker_pid;
! 
! 		/*
! 		 * Emergency bailout if postmaster has died.  This is to avoid the
! 		 * necessity for manual cleanup of all postmaster children.
! 		 */
! 		if (!PostmasterIsAlive(true))
! 			exit(1);
! 
! 		if (avlauncher_exit_request)
! 		{
! 			ereport(LOG,
! 					(errmsg("autovacuum launcher shutting down")));
! 
! 			/* Normal exit from the autovac launcher is here */
! 			proc_exit(0);		/* done */
! 		}
! 
! 		/*
! 		 * if there's a worker already running, sleep until it
! 		 * disappears.
! 		 */
! 		LWLockAcquire(AutovacuumLock, LW_SHARED);
! 		worker_pid = AutoVacuumShmem->worker_pid;
! 		LWLockRelease(AutovacuumLock);
! 
! 		if (worker_pid != 0)
! 		{
! 			PGPROC *proc = BackendPidGetProc(worker_pid);
! 
! 			if (proc != NULL && proc->isAutovacuum)
! 				goto sleep;
! 			else
! 			{
! 				/*
! 				 * if the worker is not really running (or it's a process
! 				 * that's not an autovacuum worker), remove the PID from shmem.
! 				 * This should not happen, because either the worker exits
! 				 * cleanly, in which case it'll remove the PID, or it dies, in
! 				 * which case postmaster will cause a system reset cycle.
! 				 */
! 				LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
! 				worker_pid = 0;
! 				LWLockRelease(AutovacuumLock);
! 			}
! 		}
! 
! 		/* Get a list of databases */
! 		dblist = autovac_get_database_list();
! 
! 		/*
! 		 * Determine the oldest datfrozenxid/relfrozenxid that we will allow
! 		 * to pass without forcing a vacuum.  (This limit can be tightened for
! 		 * particular tables, but not loosened.)
! 		 */
! 		recentXid = ReadNewTransactionId();
! 		xidForceLimit = recentXid - autovacuum_freeze_max_age;
! 		/* ensure it's a "normal" XID, else TransactionIdPrecedes misbehaves */
! 		if (xidForceLimit < FirstNormalTransactionId)
! 			xidForceLimit -= FirstNormalTransactionId;
! 
! 		/*
! 		 * Choose a database to connect to.  We pick the database that was least
! 		 * recently auto-vacuumed, or one that needs vacuuming to prevent Xid
! 		 * wraparound-related data loss.  If any db at risk of wraparound is
! 		 * found, we pick the one with oldest datfrozenxid, independently of
! 		 * autovacuum times.
! 		 *
! 		 * Note that a database with no stats entry is not considered, except for
! 		 * Xid wraparound purposes.  The theory is that if no one has ever
! 		 * connected to it since the stats were last initialized, it doesn't need
! 		 * vacuuming.
! 		 *
! 		 * XXX This could be improved if we had more info about whether it needs
! 		 * vacuuming before connecting to it.  Perhaps look through the pgstats
! 		 * data for the database's tables?  One idea is to keep track of the
! 		 * number of new and dead tuples per database in pgstats.  However it
! 		 * isn't clear how to construct a metric that measures that and not cause
! 		 * starvation for less busy databases.
! 		 */
! 		db = NULL;
! 		for_xid_wrap = false;
! 		foreach(cell, dblist)
! 		{
! 			autovac_dbase *tmp = lfirst(cell);
! 
! 			/* Find pgstat entry if any */
! 			tmp->entry = pgstat_fetch_stat_dbentry(tmp->oid);
! 
! 			/* Check to see if this one is at risk of wraparound */
! 			if (TransactionIdPrecedes(tmp->frozenxid, xidForceLimit))
! 			{
! 				if (db == NULL ||
! 					TransactionIdPrecedes(tmp->frozenxid, db->frozenxid))
! 					db = tmp;
! 				for_xid_wrap = true;
! 				continue;
! 			}
! 			else if (for_xid_wrap)
! 				continue;			/* ignore not-at-risk DBs */
! 
! 			/*
! 			 * Otherwise, skip a database with no pgstat entry; it means it
! 			 * hasn't seen any activity.
! 			 */
! 			if (!tmp->entry)
! 				continue;
! 
! 			/*
! 			 * Remember the db with oldest autovac time.  (If we are here,
! 			 * both tmp->entry and db->entry must be non-null.)
! 			 */
! 			if (db == NULL ||
! 				tmp->entry->last_autovac_time < db->entry->last_autovac_time)
! 				db = tmp;
! 		}
! 
! 		/* Found a database -- process it */
! 		if (db != NULL)
! 		{
! 			LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
! 			AutoVacuumShmem->process_db = db->oid;
! 			LWLockRelease(AutovacuumLock);
! 
! 			SendPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER);
! 		}
! 
! sleep:
! 		/* have pgstat read the file again next time */
! 		MemoryContextReset(AutoVacStatContext);
! 		pgstat_stathash_reset();
! 
! 		/* now sleep until the next autovac iteration */
! 		pg_usleep(autovacuum_naptime * 1000000L); 
! 	}
! }
! 
! MemoryContext
! AutoVacGetStatsContext(void)
! {
! 	return AutoVacStatContext;
! }
! 
! static void
! avlauncher_exit(SIGNAL_ARGS)
! {
! 	avlauncher_exit_request = true;
! }
! 
! /*
!  * avl_quickdie occurs when signalled SIGQUIT from postmaster.
!  *
!  * Some backend has bought the farm, so we need to stop what we're doing
!  * and exit.
!  */
! static void
! avl_quickdie(SIGNAL_ARGS)
  {
! 	PG_SETMASK(&BlockSig);
! 
! 	/*
! 	 * DO NOT proc_exit() -- we're here because shared memory may be
! 	 * corrupted, so we don't want to try to clean up our transaction. Just
! 	 * nail the windows shut and get out of town.
! 	 *
! 	 * Note we do exit(2) not exit(0).	This is to force the postmaster into a
! 	 * system reset cycle if some idiot DBA sends a manual SIGQUIT to a random
! 	 * backend.  This is necessary precisely because we don't clean up our
! 	 * shared memory state.
! 	 */
! 	exit(2);
  }
  
+ 
+ /********************************************************************
+  *                    AUTOVACUUM WORKER CODE
+  ********************************************************************/
+ 
  #ifdef EXEC_BACKEND
  /*
!  * forkexec routines for the autovacuum worker.
   *
!  * Format up the arglist, then fork and exec.
   */
  static pid_t
! avworker_forkexec(void)
  {
  	char	   *av[10];
  	int			ac = 0;
  
  	av[ac++] = "postgres";
! 	av[ac++] = "--forkavworker";
  	av[ac++] = NULL;			/* filled in by postmaster_forkexec */
  	av[ac] = NULL;
  
*************** autovac_forkexec(void)
*** 221,254 ****
   * We need this set from the outside, before InitProcess is called
   */
  void
! AutovacuumIAm(void)
  {
! 	am_autovacuum = true;
  }
- #endif   /* EXEC_BACKEND */
  
  /*
!  * AutoVacMain
   */
  NON_EXEC_STATIC void
! AutoVacMain(int argc, char *argv[])
  {
- 	ListCell   *cell;
- 	List	   *dblist;
- 	autovac_dbase *db;
- 	TransactionId xidForceLimit;
- 	bool		for_xid_wrap;
  	sigjmp_buf	local_sigjmp_buf;
  
  	/* we are a postmaster subprocess now */
  	IsUnderPostmaster = true;
! 	am_autovacuum = true;
  
  	/* reset MyProcPid */
  	MyProcPid = getpid();
  
  	/* Identify myself via ps */
! 	init_ps_display("autovacuum process", "", "", "");
  
  	SetProcessingMode(InitProcessing);
  
--- 603,673 ----
   * We need this set from the outside, before InitProcess is called
   */
  void
! AutovacuumWorkerIAm(void)
! {
! 	am_autovacuum_worker = true;
! }
! #endif
! 
! /*
!  * Main entry point for autovacuum worker process.
!  *
!  * This code is heavily based on pgarch.c, q.v.
!  */
! int
! StartAutoVacWorker(void)
  {
! 	pid_t		worker_pid;
! 
! #ifdef EXEC_BACKEND
! 	switch ((worker_pid = avworker_forkexec()))
! #else
! 	switch ((worker_pid = fork_process()))
! #endif
! 	{
! 		case -1:
! 			ereport(LOG,
! 					(errmsg("could not fork autovacuum process: %m")));
! 			return 0;
! 
! #ifndef EXEC_BACKEND
! 		case 0:
! 			/* in postmaster child ... */
! 			/* Close the postmaster's sockets */
! 			ClosePostmasterPorts(false);
! 
! 			/* Lose the postmaster's on-exit routines */
! 			on_exit_reset();
! 
! 			AutoVacWorkerMain(0, NULL);
! 			break;
! #endif
! 		default:
! 			return (int) worker_pid;
! 	}
! 
! 	/* shouldn't get here */
! 	return 0;
  }
  
  /*
!  * AutoVacWorkerMain
   */
  NON_EXEC_STATIC void
! AutoVacWorkerMain(int argc, char *argv[])
  {
  	sigjmp_buf	local_sigjmp_buf;
+ 	Oid			dbid;
  
  	/* we are a postmaster subprocess now */
  	IsUnderPostmaster = true;
! 	am_autovacuum_worker = true;
  
  	/* reset MyProcPid */
  	MyProcPid = getpid();
  
  	/* Identify myself via ps */
! 	init_ps_display("autovacuum worker process", "", "", "");
  
  	SetProcessingMode(InitProcessing);
  
*************** AutoVacMain(int argc, char *argv[])
*** 335,412 ****
  	 */
  	SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
  
- 	/* Get a list of databases */
- 	dblist = autovac_get_database_list();
- 
  	/*
! 	 * Determine the oldest datfrozenxid/relfrozenxid that we will allow
! 	 * to pass without forcing a vacuum.  (This limit can be tightened for
! 	 * particular tables, but not loosened.)
  	 */
! 	recentXid = ReadNewTransactionId();
! 	xidForceLimit = recentXid - autovacuum_freeze_max_age;
! 	/* ensure it's a "normal" XID, else TransactionIdPrecedes misbehaves */
! 	if (xidForceLimit < FirstNormalTransactionId)
! 		xidForceLimit -= FirstNormalTransactionId;
  
! 	/*
! 	 * Choose a database to connect to.  We pick the database that was least
! 	 * recently auto-vacuumed, or one that needs vacuuming to prevent Xid
! 	 * wraparound-related data loss.  If any db at risk of wraparound is
! 	 * found, we pick the one with oldest datfrozenxid,
! 	 * independently of autovacuum times.
! 	 *
! 	 * Note that a database with no stats entry is not considered, except for
! 	 * Xid wraparound purposes.  The theory is that if no one has ever
! 	 * connected to it since the stats were last initialized, it doesn't need
! 	 * vacuuming.
! 	 *
! 	 * XXX This could be improved if we had more info about whether it needs
! 	 * vacuuming before connecting to it.  Perhaps look through the pgstats
! 	 * data for the database's tables?  One idea is to keep track of the
! 	 * number of new and dead tuples per database in pgstats.  However it
! 	 * isn't clear how to construct a metric that measures that and not cause
! 	 * starvation for less busy databases.
! 	 */
! 	db = NULL;
! 	for_xid_wrap = false;
! 	foreach(cell, dblist)
! 	{
! 		autovac_dbase *tmp = lfirst(cell);
  
! 		/* Find pgstat entry if any */
! 		tmp->entry = pgstat_fetch_stat_dbentry(tmp->oid);
  
! 		/* Check to see if this one is at risk of wraparound */
! 		if (TransactionIdPrecedes(tmp->frozenxid, xidForceLimit))
! 		{
! 			if (db == NULL ||
! 				TransactionIdPrecedes(tmp->frozenxid, db->frozenxid))
! 				db = tmp;
! 			for_xid_wrap = true;
! 			continue;
! 		}
! 		else if (for_xid_wrap)
! 			continue;			/* ignore not-at-risk DBs */
! 
! 		/*
! 		 * Otherwise, skip a database with no pgstat entry; it means it
! 		 * hasn't seen any activity.
! 		 */
! 		if (!tmp->entry)
! 			continue;
! 
! 		/*
! 		 * Remember the db with oldest autovac time.  (If we are here,
! 		 * both tmp->entry and db->entry must be non-null.)
! 		 */
! 		if (db == NULL ||
! 			tmp->entry->last_autovac_time < db->entry->last_autovac_time)
! 			db = tmp;
! 	}
! 
! 	if (db)
  	{
  		/*
  		 * Report autovac startup to the stats collector.  We deliberately do
  		 * this before InitPostgres, so that the last_autovac_time will get
--- 754,777 ----
  	 */
  	SetConfigOption("zero_damaged_pages", "false", PGC_SUSET, PGC_S_OVERRIDE);
  
  	/*
! 	 * Get the database Id we're going to work on, and announce our PID
! 	 * in the shared memory area.  We remove the database OID immediately
! 	 * from the shared memory area.
  	 */
! 	LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
  
! 	dbid = AutoVacuumShmem->process_db;
! 	AutoVacuumShmem->process_db = InvalidOid;
! 	AutoVacuumShmem->worker_pid = MyProcPid;
  
! 	LWLockRelease(AutovacuumLock);
  
! 	if (OidIsValid(dbid))
  	{
+ 		char	*dbname;
+ 		PgStat_StatDBEntry *dbentry;
+ 
  		/*
  		 * Report autovac startup to the stats collector.  We deliberately do
  		 * this before InitPostgres, so that the last_autovac_time will get
*************** AutoVacMain(int argc, char *argv[])
*** 415,421 ****
  		 * database, rather than making any progress on stuff it can connect
  		 * to.
  		 */
! 		pgstat_report_autovac(db->oid);
  
  		/*
  		 * Connect to the selected database
--- 780,793 ----
  		 * database, rather than making any progress on stuff it can connect
  		 * to.
  		 */
! 		pgstat_report_autovac(dbid);
! 
! 		/*
! 		 * FIXME -- maybe it's better to change InitPostgres to be able to
! 		 * receive an OID, so that we don't have to read the pg_database
! 		 * flatfile again?
! 		 */
! 		dbname = autovac_get_database_name(dbid);
  
  		/*
  		 * Connect to the selected database
*************** AutoVacMain(int argc, char *argv[])
*** 423,433 ****
  		 * Note: if we have selected a just-deleted database (due to using
  		 * stale stats info), we'll fail and exit here.
  		 */
! 		InitPostgres(db->name, NULL);
  		SetProcessingMode(NormalProcessing);
! 		set_ps_display(db->name, false);
  		ereport(DEBUG1,
! 				(errmsg("autovacuum: processing database \"%s\"", db->name)));
  
  		/* Create the memory context where cross-transaction state is stored */
  		AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
--- 795,805 ----
  		 * Note: if we have selected a just-deleted database (due to using
  		 * stale stats info), we'll fail and exit here.
  		 */
! 		InitPostgres(dbname, NULL);
  		SetProcessingMode(NormalProcessing);
! 		set_ps_display(dbname, false);
  		ereport(DEBUG1,
! 				(errmsg("autovacuum: processing database \"%s\"", dbname)));
  
  		/* Create the memory context where cross-transaction state is stored */
  		AutovacMemCxt = AllocSetContextCreate(TopMemoryContext,
*************** AutoVacMain(int argc, char *argv[])
*** 439,448 ****
  		/*
  		 * And do an appropriate amount of work
  		 */
! 		do_autovacuum(db->entry);
  	}
  
! 	/* One iteration done, go away */
  	proc_exit(0);
  }
  
--- 811,829 ----
  		/*
  		 * And do an appropriate amount of work
  		 */
! 		dbentry = pgstat_fetch_stat_dbentry(dbid);
! 		do_autovacuum(dbentry);
  	}
  
! 	/*
! 	 * Now remove our PID from shared memory, so that the launcher can start
! 	 * another worker as soon as appropriate.
! 	 */
! 	LWLockAcquire(AutovacuumLock, LW_EXCLUSIVE);
! 	AutoVacuumShmem->worker_pid = 0;
! 	LWLockRelease(AutovacuumLock);
! 
! 	/* All done, go away */
  	proc_exit(0);
  }
  
*************** AutoVacMain(int argc, char *argv[])
*** 450,456 ****
   * autovac_get_database_list
   *
   *		Return a list of all databases.  Note we cannot use pg_database,
!  *		because we aren't connected yet; we use the flat database file.
   */
  static List *
  autovac_get_database_list(void)
--- 831,837 ----
   * autovac_get_database_list
   *
   *		Return a list of all databases.  Note we cannot use pg_database,
!  *		because we aren't connected; we use the flat database file.
   */
  static List *
  autovac_get_database_list(void)
*************** autovac_get_database_list(void)
*** 493,498 ****
--- 874,920 ----
  }
  
  /*
+  * autovac_get_database_name
+  *
+  * 		Given a database OID, get its name from the flat database file.
+  */
+ static char *
+ autovac_get_database_name(Oid dbid)
+ {
+ 	char   *filename;
+ 	char   *dbname = NULL;
+ 	Oid		this_oid;
+ 	Oid		dummy_oid;
+ 	FILE   *db_file;
+ 	char	thisname[NAMEDATALEN];
+ 	
+ 	filename = database_getflatfilename();
+ 	db_file = AllocateFile(filename, "r");
+ 	if (db_file == NULL)
+ 		ereport(FATAL,
+ 				(errcode_for_file_access(),
+ 				 errmsg("could not open file \"%s\": %m", filename)));
+ 
+ 	while (read_pg_database_line(db_file, thisname, &this_oid,
+ 								 &dummy_oid, &dummy_oid))
+ 	{
+ 		if (this_oid == dbid)
+ 		{
+ 			dbname = pstrdup(thisname);
+ 			break;
+ 		}
+ 	}
+ 
+ 	if (dbname == NULL)
+ 		elog(FATAL, "could not find name for database %u", dbid);
+ 
+ 	FreeFile(db_file);
+ 	pfree(filename);
+ 
+ 	return dbname;
+ }
+ 
+ /*
   * Process a database table-by-table
   *
   * dbentry is either a pointer to the database entry in the stats databases
*************** autovac_init(void)
*** 1011,1021 ****
  }
  
  /*
!  * IsAutoVacuumProcess
!  *		Return whether this process is an autovacuum process.
   */
  bool
! IsAutoVacuumProcess(void)
  {
! 	return am_autovacuum;
  }
--- 1433,1484 ----
  }
  
  /*
!  * IsAutoVacuum functions
!  *		Return whether this is either a launcher autovacuum process or a worker
!  *		process.
   */
  bool
! IsAutoVacuumLauncherProcess(void)
! {
! 	return am_autovacuum_launcher;
! }
! 
! bool
! IsAutoVacuumWorkerProcess(void)
! {
! 	return am_autovacuum_worker;
! }
! 
! 
! /*
!  * AutoVacuumShmemSize
!  * 		Compute space needed for autovacuum-related shared memory
!  */
! Size
! AutoVacuumShmemSize(void)
  {
! 	return sizeof(AutoVacuumShmemStruct);
! }
! 
! /*
!  * AutoVacuumShmemInit
!  *		Allocate and initialize autovacuum-related shared memory
!  */
! void
! AutoVacuumShmemInit(void)
! {
! 	bool        found;
! 
! 	AutoVacuumShmem = (AutoVacuumShmemStruct *)
! 		ShmemInitStruct("AutoVacuum Data",
! 						AutoVacuumShmemSize(),
! 						&found);
! 	if (AutoVacuumShmem == NULL)
! 		ereport(FATAL,
! 				(errcode(ERRCODE_OUT_OF_MEMORY),
! 				 errmsg("not enough shared memory for autovacuum")));
! 	if (found)
! 		return;                 /* already initialized */
! 
! 	MemSet(AutoVacuumShmem, 0, sizeof(AutoVacuumShmemStruct));
  }
Index: src/backend/postmaster/pgstat.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/postmaster/pgstat.c,v
retrieving revision 1.143
diff -c -p -r1.143 pgstat.c
*** src/backend/postmaster/pgstat.c	11 Jan 2007 23:06:03 -0000	1.143
--- src/backend/postmaster/pgstat.c	26 Jan 2007 17:23:00 -0000
*************** static time_t last_pgstat_start_time;
*** 110,115 ****
--- 110,116 ----
  
  static bool pgStatRunningInCollector = false;
  
+ 
  /*
   * Place where backends store per-table info to be sent to the collector.
   * We store shared relations separately from non-shared ones, to be able to
*************** static TabStatArray SharedTabStat = {0, 
*** 130,135 ****
--- 131,137 ----
  static int	pgStatXactCommit = 0;
  static int	pgStatXactRollback = 0;
  
+ static bool stathash_set = false;
  static TransactionId pgStatDBHashXact = InvalidTransactionId;
  static HTAB *pgStatDBHash = NULL;
  static TransactionId pgStatLocalStatusXact = InvalidTransactionId;
*************** pgstat_report_vacuum(Oid tableoid, bool 
*** 930,936 ****
  	msg.m_databaseid = shared ? InvalidOid : MyDatabaseId;
  	msg.m_tableoid = tableoid;
  	msg.m_analyze = analyze;
! 	msg.m_autovacuum = IsAutoVacuumProcess();	/* is this autovacuum? */
  	msg.m_vacuumtime = GetCurrentTimestamp();
  	msg.m_tuples = tuples;
  	pgstat_send(&msg, sizeof(msg));
--- 932,938 ----
  	msg.m_databaseid = shared ? InvalidOid : MyDatabaseId;
  	msg.m_tableoid = tableoid;
  	msg.m_analyze = analyze;
! 	msg.m_autovacuum = IsAutoVacuumWorkerProcess();	/* is this autovacuum? */
  	msg.m_vacuumtime = GetCurrentTimestamp();
  	msg.m_tuples = tuples;
  	pgstat_send(&msg, sizeof(msg));
*************** pgstat_report_analyze(Oid tableoid, bool
*** 955,961 ****
  	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ANALYZE);
  	msg.m_databaseid = shared ? InvalidOid : MyDatabaseId;
  	msg.m_tableoid = tableoid;
! 	msg.m_autovacuum = IsAutoVacuumProcess();	/* is this autovacuum? */
  	msg.m_analyzetime = GetCurrentTimestamp();
  	msg.m_live_tuples = livetuples;
  	msg.m_dead_tuples = deadtuples;
--- 957,963 ----
  	pgstat_setheader(&msg.m_hdr, PGSTAT_MTYPE_ANALYZE);
  	msg.m_databaseid = shared ? InvalidOid : MyDatabaseId;
  	msg.m_tableoid = tableoid;
! 	msg.m_autovacuum = IsAutoVacuumWorkerProcess();	/* is this autovacuum? */
  	msg.m_analyzetime = GetCurrentTimestamp();
  	msg.m_live_tuples = livetuples;
  	msg.m_dead_tuples = deadtuples;
*************** pgstat_read_statsfile(HTAB **dbhash, Oid
*** 2098,2110 ****
  	int			mcxt_flags;
  
  	/*
! 	 * If running in the collector or the autovacuum process, we use the
! 	 * DynaHashCxt memory context.	If running in a backend, we use the
! 	 * TopTransactionContext instead, so the caller must only know the last
! 	 * XactId when this call happened to know if his tables are still valid or
! 	 * already gone!
  	 */
! 	if (pgStatRunningInCollector || IsAutoVacuumProcess())
  	{
  		use_mcxt = NULL;
  		mcxt_flags = 0;
--- 2100,2118 ----
  	int			mcxt_flags;
  
  	/*
! 	 * If running in the collector or an autovacuum worker process, we use the
! 	 * DynaHashCxt memory context.	If running in the autovacuum launcher, we
! 	 * use a context that process will provide us.  If running in a backend, we
! 	 * use the TopTransactionContext instead, so the caller must only know the
! 	 * last XactId when this call happened to know if his tables are still
! 	 * valid or already gone!
  	 */
! 	if (IsAutoVacuumLauncherProcess())
! 	{
! 		use_mcxt = AutoVacGetStatsContext();
! 		mcxt_flags = HASH_CONTEXT;
! 	}
! 	else if (pgStatRunningInCollector || IsAutoVacuumWorkerProcess())
  	{
  		use_mcxt = NULL;
  		mcxt_flags = 0;
*************** done:
*** 2269,2289 ****
  }
  
  /*
   * If not done for this transaction, read the statistics collector
   * stats file into some hash tables.
   *
   * Because we store the tables in TopTransactionContext, the result
   * is good for the entire current main transaction.
   *
!  * Inside the autovacuum process, the statfile is assumed to be valid
   * "forever", that is one iteration, within one database.  This means
   * we only consider the statistics as they were when the autovacuum
   * iteration started.
   */
  static void
  backend_read_statsfile(void)
  {
! 	if (IsAutoVacuumProcess())
  	{
  		/* already read it? */
  		if (pgStatDBHash)
--- 2277,2319 ----
  }
  
  /*
+  * Called when the memory context that holds the stathash has been reset,
+  * i.e., we have to read the stats file again.
+  */
+ void
+ pgstat_stathash_reset(void)
+ {
+ 	stathash_set = false;
+ }
+ 
+ /*
   * If not done for this transaction, read the statistics collector
   * stats file into some hash tables.
   *
   * Because we store the tables in TopTransactionContext, the result
   * is good for the entire current main transaction.
   *
!  * Inside an autovacuum worker process, the statfile is assumed to be valid
   * "forever", that is one iteration, within one database.  This means
   * we only consider the statistics as they were when the autovacuum
   * iteration started.
+  *
+  * Inside the autovacuum launcher process, we store the tables in a
+  * memory context that's reset after each check iteration.  It'll tell us
+  * when the context has been reset by calling pgstat_stathash_reset.
   */
  static void
  backend_read_statsfile(void)
  {
! 	if (IsAutoVacuumLauncherProcess())
! 	{
! 		if (stathash_set)
! 			return;
! 		Assert(!pgStatRunningInCollector);
! 		pgstat_read_statsfile(&pgStatDBHash, InvalidOid);
! 		stathash_set = true;
! 	}
! 	else if (IsAutoVacuumWorkerProcess())
  	{
  		/* already read it? */
  		if (pgStatDBHash)
Index: src/backend/postmaster/postmaster.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/postmaster/postmaster.c,v
retrieving revision 1.512
diff -c -p -r1.512 postmaster.c
*** src/backend/postmaster/postmaster.c	23 Jan 2007 03:28:49 -0000	1.512
--- src/backend/postmaster/postmaster.c	26 Jan 2007 23:13:43 -0000
***************
*** 129,141 ****
   * authorization phase).  This is used mainly to keep track of how many
   * children we have and send them appropriate signals when necessary.
   *
!  * "Special" children such as the startup and bgwriter tasks are not in
!  * this list.
   */
  typedef struct bkend
  {
  	pid_t		pid;			/* process id of backend */
  	long		cancel_key;		/* cancel key for cancels for this backend */
  } Backend;
  
  static Dllist *BackendList;
--- 129,143 ----
   * authorization phase).  This is used mainly to keep track of how many
   * children we have and send them appropriate signals when necessary.
   *
!  * "Special" children such as the startup, bgwriter and autovacuum launcher
!  * tasks are not in this list.  Autovacuum worker processes, however, *are* on
!  * it.
   */
  typedef struct bkend
  {
  	pid_t		pid;			/* process id of backend */
  	long		cancel_key;		/* cancel key for cancels for this backend */
+ 	bool		is_autovacuum;	/* is it an autovacuum worker? */
  } Backend;
  
  static Dllist *BackendList;
*************** bool		ClientAuthInProgress = false;		/* 
*** 218,223 ****
--- 220,226 ----
  												 * authentication */
  
  static bool force_autovac = false; /* received START_AUTOVAC signal */
+ static bool start_autovac_worker = false;
  
  /*
   * State for assigning random salts and cancel keys.
*************** ServerLoop(void)
*** 1145,1157 ****
  		/*
  		 * Wait for something to happen.
  		 *
! 		 * We wait at most one minute, or the minimum autovacuum delay, to
! 		 * ensure that the other background tasks handled below get done even
! 		 * when no requests are arriving.
  		 */
  		memcpy((char *) &rmask, (char *) &readmask, sizeof(fd_set));
  
! 		timeout.tv_sec = Min(60, autovacuum_naptime);
  		timeout.tv_usec = 0;
  
  		PG_SETMASK(&UnBlockSig);
--- 1148,1159 ----
  		/*
  		 * Wait for something to happen.
  		 *
! 		 * We wait at most one minute, to ensure that the other background
! 		 * tasks handled below get done even when no requests are arriving.
  		 */
  		memcpy((char *) &rmask, (char *) &readmask, sizeof(fd_set));
  
! 		timeout.tv_sec = 60;
  		timeout.tv_usec = 0;
  
  		PG_SETMASK(&UnBlockSig);
*************** ServerLoop(void)
*** 1238,1256 ****
  				signal_child(BgWriterPID, SIGUSR2);
  		}
  
! 		/*
! 		 * Start a new autovacuum process, if there isn't one running already.
! 		 * (It'll die relatively quickly.)  We check that it's not started too
! 		 * frequently in autovac_start.
! 		 */
  		if ((AutoVacuumingActive() || force_autovac) && AutoVacPID == 0 &&
  			StartupPID == 0 && !FatalError && Shutdown == NoShutdown)
  		{
! 			AutoVacPID = autovac_start();
  			if (AutoVacPID != 0)
  				force_autovac = false;	/* signal successfully processed */
  		}
  
  		/* If we have lost the archiver, try to start a new one */
  		if (XLogArchivingActive() && PgArchPID == 0 &&
  			StartupPID == 0 && !FatalError && Shutdown == NoShutdown)
--- 1240,1279 ----
  				signal_child(BgWriterPID, SIGUSR2);
  		}
  
! 		/* If we have lost the autovacuum launcher, try to start a new one */
  		if ((AutoVacuumingActive() || force_autovac) && AutoVacPID == 0 &&
  			StartupPID == 0 && !FatalError && Shutdown == NoShutdown)
  		{
! 			AutoVacPID = StartAutoVacLauncher();
  			if (AutoVacPID != 0)
  				force_autovac = false;	/* signal successfully processed */
  		}
  
+ 		if (start_autovac_worker && !FatalError && Shutdown == NoShutdown)
+ 		{
+ 			Backend	   *bn;
+ 
+ 			start_autovac_worker = false;
+ 			bn = (Backend *) malloc(sizeof(Backend));
+ 			if (!bn)
+ 			{
+ 				ereport(LOG,
+ 						(errcode(ERRCODE_OUT_OF_MEMORY),
+ 						 errmsg("out of memory")));
+ 			}
+ 			else
+ 			{
+ 				bn->pid = StartAutoVacWorker();
+ 				if (bn->pid > 0)
+ 				{
+ 					DLAddHead(BackendList, DLNewElem(bn));
+ #ifdef EXEC_BACKEND
+ 					ShmemBackendArrayAdd(bn);
+ #endif
+ 				}
+ 			}
+ 		}
+ 
  		/* If we have lost the archiver, try to start a new one */
  		if (XLogArchivingActive() && PgArchPID == 0 &&
  			StartupPID == 0 && !FatalError && Shutdown == NoShutdown)
*************** pmdie(SIGNAL_ARGS)
*** 1873,1888 ****
  			ereport(LOG,
  					(errmsg("received smart shutdown request")));
  
- 			/*
- 			 * We won't wait out an autovacuum iteration ...
- 			 */
- 			if (AutoVacPID != 0)
- 			{
- 				/* Use statement cancel to shut it down */
- 				signal_child(AutoVacPID, SIGINT);
- 				break;			/* let reaper() handle this */
- 			}
- 
  			if (DLGetHead(BackendList))
  				break;			/* let reaper() handle this */
  
--- 1896,1901 ----
*************** pmdie(SIGNAL_ARGS)
*** 1903,1908 ****
--- 1916,1924 ----
  			/* Tell pgstat to shut down too; nothing left for it to do */
  			if (PgStatPID != 0)
  				signal_child(PgStatPID, SIGQUIT);
+ 			/* Tell autovac launcher to shut down too */
+ 			if (AutoVacPID != 0)
+ 				signal_child(AutoVacPID, SIGTERM);
  			break;
  
  		case SIGINT:
*************** pmdie(SIGNAL_ARGS)
*** 1919,1933 ****
  			ereport(LOG,
  					(errmsg("received fast shutdown request")));
  
! 			if (DLGetHead(BackendList) || AutoVacPID != 0)
  			{
  				if (!FatalError)
  				{
  					ereport(LOG,
  							(errmsg("aborting any active transactions")));
  					SignalChildren(SIGTERM);
- 					if (AutoVacPID != 0)
- 						signal_child(AutoVacPID, SIGTERM);
  					/* reaper() does the rest */
  				}
  				break;
--- 1935,1947 ----
  			ereport(LOG,
  					(errmsg("received fast shutdown request")));
  
! 			if (DLGetHead(BackendList))
  			{
  				if (!FatalError)
  				{
  					ereport(LOG,
  							(errmsg("aborting any active transactions")));
  					SignalChildren(SIGTERM);
  					/* reaper() does the rest */
  				}
  				break;
*************** pmdie(SIGNAL_ARGS)
*** 1958,1963 ****
--- 1972,1980 ----
  			/* Tell pgstat to shut down too; nothing left for it to do */
  			if (PgStatPID != 0)
  				signal_child(PgStatPID, SIGQUIT);
+ 			/* Tell autovac launcher to shut down too */
+ 			if (AutoVacPID != 0)
+ 				signal_child(AutoVacPID, SIGTERM);
  			break;
  
  		case SIGQUIT:
*************** reaper(SIGNAL_ARGS)
*** 2072,2079 ****
  
  			/*
  			 * Go to shutdown mode if a shutdown request was pending.
! 			 * Otherwise, try to start the archiver and stats collector too.
! 			 * (We could, but don't, try to start autovacuum here.)
  			 */
  			if (Shutdown > NoShutdown && BgWriterPID != 0)
  				signal_child(BgWriterPID, SIGUSR2);
--- 2089,2096 ----
  
  			/*
  			 * Go to shutdown mode if a shutdown request was pending.
! 			 * Otherwise, try to start the archiver, stats collector and
! 			 * autovacuum launcher.
  			 */
  			if (Shutdown > NoShutdown && BgWriterPID != 0)
  				signal_child(BgWriterPID, SIGUSR2);
*************** reaper(SIGNAL_ARGS)
*** 2083,2088 ****
--- 2100,2107 ----
  					PgArchPID = pgarch_start();
  				if (PgStatPID == 0)
  					PgStatPID = pgstat_start();
+ 				if (AutoVacuumingActive() && AutoVacPID == 0)
+ 					AutoVacPID = StartAutoVacLauncher();
  			}
  
  			continue;
*************** reaper(SIGNAL_ARGS)
*** 2137,2154 ****
  		}
  
  		/*
! 		 * Was it the autovacuum process?  Normal or FATAL exit can be
! 		 * ignored; we'll start a new one at the next iteration of the
! 		 * postmaster's main loop, if necessary.  Any other exit condition
! 		 * is treated as a crash.
  		 */
  		if (AutoVacPID != 0 && pid == AutoVacPID)
  		{
  			AutoVacPID = 0;
! 			autovac_stopped();
! 			if (!EXIT_STATUS_0(exitstatus) && !EXIT_STATUS_1(exitstatus))
  				HandleChildCrash(pid, exitstatus,
! 								 _("autovacuum process"));
  			continue;
  		}
  
--- 2156,2171 ----
  		}
  
  		/*
! 		 * Was it the autovacuum launcher?  Normal exit can be ignored; we'll
! 		 * start a new one at the next iteration of the postmaster's main loop,
! 		 * if necessary.  Any other exit condition is treated as a crash.
  		 */
  		if (AutoVacPID != 0 && pid == AutoVacPID)
  		{
  			AutoVacPID = 0;
! 			if (!EXIT_STATUS_0(exitstatus))
  				HandleChildCrash(pid, exitstatus,
! 								 _("autovacuum launcher process"));
  			continue;
  		}
  
*************** reaper(SIGNAL_ARGS)
*** 2226,2232 ****
  
  	if (Shutdown > NoShutdown)
  	{
! 		if (DLGetHead(BackendList) || StartupPID != 0 || AutoVacPID != 0)
  			goto reaper_done;
  		/* Start the bgwriter if not running */
  		if (BgWriterPID == 0)
--- 2243,2249 ----
  
  	if (Shutdown > NoShutdown)
  	{
! 		if (DLGetHead(BackendList) || StartupPID != 0)
  			goto reaper_done;
  		/* Start the bgwriter if not running */
  		if (BgWriterPID == 0)
*************** reaper(SIGNAL_ARGS)
*** 2240,2245 ****
--- 2257,2265 ----
  		/* Tell pgstat to shut down too; nothing left for it to do */
  		if (PgStatPID != 0)
  			signal_child(PgStatPID, SIGQUIT);
+ 		/* Tell autovac launcher to shut down too */
+ 		if (AutoVacPID != 0)
+ 			signal_child(AutoVacPID, SIGTERM);
  	}
  
  reaper_done:
*************** HandleChildCrash(int pid, int exitstatus
*** 2367,2373 ****
  		signal_child(BgWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
  	}
  
! 	/* Take care of the autovacuum daemon too */
  	if (pid == AutoVacPID)
  		AutoVacPID = 0;
  	else if (AutoVacPID != 0 && !FatalError)
--- 2387,2393 ----
  		signal_child(BgWriterPID, (SendStop ? SIGSTOP : SIGQUIT));
  	}
  
! 	/* Take care of the autovacuum launcher too */
  	if (pid == AutoVacPID)
  		AutoVacPID = 0;
  	else if (AutoVacPID != 0 && !FatalError)
*************** signal_child(pid_t pid, int signal)
*** 2487,2493 ****
  }
  
  /*
!  * Send a signal to all backend children (but NOT special children)
   */
  static void
  SignalChildren(int signal)
--- 2507,2514 ----
  }
  
  /*
!  * Send a signal to all backend children, including autovacuum workers (but NOT
!  * special children)
   */
  static void
  SignalChildren(int signal)
*************** SubPostmasterMain(int argc, char *argv[]
*** 3305,3317 ****
  	 * same address the postmaster used.
  	 */
  	if (strcmp(argv[1], "--forkbackend") == 0 ||
! 		strcmp(argv[1], "--forkautovac") == 0 ||
  		strcmp(argv[1], "--forkboot") == 0)
  		PGSharedMemoryReAttach();
  
  	/* autovacuum needs this set before calling InitProcess */
! 	if (strcmp(argv[1], "--forkautovac") == 0)
! 		AutovacuumIAm();
  
  	/*
  	 * Start our win32 signal implementation. This has to be done after we
--- 3326,3341 ----
  	 * same address the postmaster used.
  	 */
  	if (strcmp(argv[1], "--forkbackend") == 0 ||
! 		strcmp(argv[1], "--forkavlauncher") == 0 ||
! 		strcmp(argv[1], "--forkavworker") == 0 ||
  		strcmp(argv[1], "--forkboot") == 0)
  		PGSharedMemoryReAttach();
  
  	/* autovacuum needs this set before calling InitProcess */
! 	if (strcmp(argv[1], "--forkavlauncher") == 0)
! 		AutovacuumLauncherIAm();
! 	if (strcmp(argv[1], "--forkavworker") == 0)
! 		AutovacuumWorkerIAm();
  
  	/*
  	 * Start our win32 signal implementation. This has to be done after we
*************** SubPostmasterMain(int argc, char *argv[]
*** 3397,3403 ****
  		BootstrapMain(argc - 2, argv + 2);
  		proc_exit(0);
  	}
! 	if (strcmp(argv[1], "--forkautovac") == 0)
  	{
  		/* Close the postmaster's sockets */
  		ClosePostmasterPorts(false);
--- 3421,3444 ----
  		BootstrapMain(argc - 2, argv + 2);
  		proc_exit(0);
  	}
! 	if (strcmp(argv[1], "--forkavlauncher") == 0)
! 	{
! 		/* Close the postmaster's sockets */
! 		ClosePostmasterPorts(false);
! 
! 		/* Restore basic shared memory pointers */
! 		InitShmemAccess(UsedShmemSegAddr);
! 
! 		/* Need a PGPROC to run CreateSharedMemoryAndSemaphores */
! 		InitDummyProcess();
! 
! 		/* Attach process to shared data structures */
! 		CreateSharedMemoryAndSemaphores(false, 0);
! 
! 		AutoVacLauncherMain(argc - 2, argv + 2);
! 		proc_exit(0);
! 	}
! 	if (strcmp(argv[1], "--forkavworker") == 0)
  	{
  		/* Close the postmaster's sockets */
  		ClosePostmasterPorts(false);
*************** SubPostmasterMain(int argc, char *argv[]
*** 3411,3417 ****
  		/* Attach process to shared data structures */
  		CreateSharedMemoryAndSemaphores(false, 0);
  
! 		AutoVacMain(argc - 2, argv + 2);
  		proc_exit(0);
  	}
  	if (strcmp(argv[1], "--forkarch") == 0)
--- 3452,3458 ----
  		/* Attach process to shared data structures */
  		CreateSharedMemoryAndSemaphores(false, 0);
  
! 		AutoVacWorkerMain(argc - 2, argv + 2);
  		proc_exit(0);
  	}
  	if (strcmp(argv[1], "--forkarch") == 0)
*************** sigusr1_handler(SIGNAL_ARGS)
*** 3495,3505 ****
  		 * See storage/ipc/sinval[adt].c for the use of this.
  		 */
  		if (Shutdown <= SmartShutdown)
- 		{
  			SignalChildren(SIGUSR1);
- 			if (AutoVacPID != 0)
- 				signal_child(AutoVacPID, SIGUSR1);
- 		}
  	}
  
  	if (CheckPostmasterSignal(PMSIGNAL_WAKEN_ARCHIVER) &&
--- 3536,3542 ----
*************** sigusr1_handler(SIGNAL_ARGS)
*** 3519,3525 ****
  		signal_child(SysLoggerPID, SIGUSR1);
  	}
  
! 	if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC))
  	{
  		/*
  		 * Start one iteration of the autovacuum daemon, even if autovacuuming
--- 3556,3562 ----
  		signal_child(SysLoggerPID, SIGUSR1);
  	}
  
! 	if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_LAUNCHER))
  	{
  		/*
  		 * Start one iteration of the autovacuum daemon, even if autovacuuming
*************** sigusr1_handler(SIGNAL_ARGS)
*** 3533,3538 ****
--- 3570,3584 ----
  		force_autovac = true;
  	}
  
+ 	if (CheckPostmasterSignal(PMSIGNAL_START_AUTOVAC_WORKER))
+ 	{
+ 		/*
+ 		 * The autovacuum launcher wants us to start an autovacuum worker
+ 		 * process.  Let the main loop do it.
+ 		 */
+ 		start_autovac_worker = true;
+ 	}
+ 
  	PG_SETMASK(&UnBlockSig);
  
  	errno = save_errno;
Index: src/backend/storage/ipc/ipci.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/storage/ipc/ipci.c,v
retrieving revision 1.90
diff -c -p -r1.90 ipci.c
*** src/backend/storage/ipc/ipci.c	5 Jan 2007 22:19:37 -0000	1.90
--- src/backend/storage/ipc/ipci.c	26 Jan 2007 17:23:00 -0000
***************
*** 21,26 ****
--- 21,27 ----
  #include "access/twophase.h"
  #include "miscadmin.h"
  #include "pgstat.h"
+ #include "postmaster/autovacuum.h"
  #include "postmaster/bgwriter.h"
  #include "postmaster/postmaster.h"
  #include "storage/freespace.h"
*************** CreateSharedMemoryAndSemaphores(bool mak
*** 109,114 ****
--- 110,116 ----
  		size = add_size(size, SInvalShmemSize());
  		size = add_size(size, FreeSpaceShmemSize());
  		size = add_size(size, BgWriterShmemSize());
+ 		size = add_size(size, AutoVacuumShmemSize());
  		size = add_size(size, BTreeShmemSize());
  #ifdef EXEC_BACKEND
  		size = add_size(size, ShmemBackendArraySize());
*************** CreateSharedMemoryAndSemaphores(bool mak
*** 208,213 ****
--- 210,216 ----
  	 */
  	PMSignalInit();
  	BgWriterShmemInit();
+ 	AutoVacuumShmemInit();
  
  	/*
  	 * Set up other modules that need some shared memory space
Index: src/backend/storage/lmgr/proc.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/storage/lmgr/proc.c,v
retrieving revision 1.183
diff -c -p -r1.183 proc.c
*** src/backend/storage/lmgr/proc.c	16 Jan 2007 13:28:56 -0000	1.183
--- src/backend/storage/lmgr/proc.c	26 Jan 2007 23:08:05 -0000
*************** InitProcess(void)
*** 259,265 ****
  	MyProc->databaseId = InvalidOid;
  	MyProc->roleId = InvalidOid;
  	MyProc->inVacuum = false;
! 	MyProc->isAutovacuum = IsAutoVacuumProcess();
  	MyProc->lwWaiting = false;
  	MyProc->lwExclusive = false;
  	MyProc->lwWaitLink = NULL;
--- 259,265 ----
  	MyProc->databaseId = InvalidOid;
  	MyProc->roleId = InvalidOid;
  	MyProc->inVacuum = false;
! 	MyProc->isAutovacuum = IsAutoVacuumWorkerProcess();
  	MyProc->lwWaiting = false;
  	MyProc->lwExclusive = false;
  	MyProc->lwWaitLink = NULL;
*************** InitDummyProcess(void)
*** 392,398 ****
  	MyProc->databaseId = InvalidOid;
  	MyProc->roleId = InvalidOid;
  	MyProc->inVacuum = false;
! 	MyProc->isAutovacuum = false;
  	MyProc->lwWaiting = false;
  	MyProc->lwExclusive = false;
  	MyProc->lwWaitLink = NULL;
--- 392,398 ----
  	MyProc->databaseId = InvalidOid;
  	MyProc->roleId = InvalidOid;
  	MyProc->inVacuum = false;
! 	MyProc->isAutovacuum = IsAutoVacuumLauncherProcess(); /* is this needed? */
  	MyProc->lwWaiting = false;
  	MyProc->lwExclusive = false;
  	MyProc->lwWaitLink = NULL;
Index: src/backend/utils/init/miscinit.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/utils/init/miscinit.c,v
retrieving revision 1.160
diff -c -p -r1.160 miscinit.c
*** src/backend/utils/init/miscinit.c	5 Jan 2007 22:19:44 -0000	1.160
--- src/backend/utils/init/miscinit.c	26 Jan 2007 23:08:32 -0000
*************** InitializeSessionUserId(const char *role
*** 401,407 ****
  	 *
  	 * We do not enforce them for the autovacuum process either.
  	 */
! 	if (IsUnderPostmaster && !IsAutoVacuumProcess())
  	{
  		/*
  		 * Is role allowed to login at all?
--- 401,407 ----
  	 *
  	 * We do not enforce them for the autovacuum process either.
  	 */
! 	if (IsUnderPostmaster && !IsAutoVacuumWorkerProcess())
  	{
  		/*
  		 * Is role allowed to login at all?
*************** void
*** 462,468 ****
  InitializeSessionUserIdStandalone(void)
  {
  	/* This function should only be called in a single-user backend. */
! 	AssertState(!IsUnderPostmaster || IsAutoVacuumProcess());
  
  	/* call only once */
  	AssertState(!OidIsValid(AuthenticatedUserId));
--- 462,468 ----
  InitializeSessionUserIdStandalone(void)
  {
  	/* This function should only be called in a single-user backend. */
! 	AssertState(!IsUnderPostmaster || IsAutoVacuumWorkerProcess());
  
  	/* call only once */
  	AssertState(!OidIsValid(AuthenticatedUserId));
Index: src/backend/utils/init/postinit.c
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/backend/utils/init/postinit.c,v
retrieving revision 1.173
diff -c -p -r1.173 postinit.c
*** src/backend/utils/init/postinit.c	5 Jan 2007 22:19:44 -0000	1.173
--- src/backend/utils/init/postinit.c	26 Jan 2007 23:05:23 -0000
*************** CheckMyDatabase(const char *name, bool a
*** 135,143 ****
  	 * a way to recover from disabling all access to all databases, for
  	 * example "UPDATE pg_database SET datallowconn = false;".
  	 *
! 	 * We do not enforce them for the autovacuum process either.
  	 */
! 	if (IsUnderPostmaster && !IsAutoVacuumProcess())
  	{
  		/*
  		 * Check that the database is currently allowing connections.
--- 135,143 ----
  	 * a way to recover from disabling all access to all databases, for
  	 * example "UPDATE pg_database SET datallowconn = false;".
  	 *
! 	 * We do not enforce them for the autovacuum worker processes either.
  	 */
! 	if (IsUnderPostmaster && !IsAutoVacuumWorkerProcess())
  	{
  		/*
  		 * Check that the database is currently allowing connections.
*************** bool
*** 288,294 ****
  InitPostgres(const char *dbname, const char *username)
  {
  	bool		bootstrap = IsBootstrapProcessingMode();
! 	bool		autovacuum = IsAutoVacuumProcess();
  	bool		am_superuser;
  	char	   *fullpath;
  
--- 288,294 ----
  InitPostgres(const char *dbname, const char *username)
  {
  	bool		bootstrap = IsBootstrapProcessingMode();
! 	bool		autovacuum = IsAutoVacuumWorkerProcess();
  	bool		am_superuser;
  	char	   *fullpath;
  
Index: src/include/c.h
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/include/c.h,v
retrieving revision 1.217
diff -c -p -r1.217 c.h
*** src/include/c.h	25 Jan 2007 03:30:43 -0000	1.217
--- src/include/c.h	26 Jan 2007 16:39:14 -0000
*************** extern int	fdatasync(int fildes);
*** 817,822 ****
--- 817,823 ----
  #define HAVE_STRTOULL 1
  #endif
  
+ #define EXEC_BACKEND
  /* EXEC_BACKEND defines */
  #ifdef EXEC_BACKEND
  #define NON_EXEC_STATIC
Index: src/include/pgstat.h
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/include/pgstat.h,v
retrieving revision 1.52
diff -c -p -r1.52 pgstat.h
*** src/include/pgstat.h	5 Jan 2007 22:19:50 -0000	1.52
--- src/include/pgstat.h	26 Jan 2007 16:39:14 -0000
*************** extern PgStat_StatDBEntry *pgstat_fetch_
*** 481,485 ****
--- 481,486 ----
  extern PgStat_StatTabEntry *pgstat_fetch_stat_tabentry(Oid relid);
  extern PgBackendStatus *pgstat_fetch_stat_beentry(int beid);
  extern int	pgstat_fetch_stat_numbackends(void);
+ extern void pgstat_stathash_reset(void);
  
  #endif   /* PGSTAT_H */
Index: src/include/postmaster/autovacuum.h
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/include/postmaster/autovacuum.h,v
retrieving revision 1.7
diff -c -p -r1.7 autovacuum.h
*** src/include/postmaster/autovacuum.h	16 Jan 2007 13:28:57 -0000	1.7
--- src/include/postmaster/autovacuum.h	26 Jan 2007 23:07:09 -0000
*************** extern int	autovacuum_vac_cost_limit;
*** 27,42 ****
  
  /* Status inquiry functions */
  extern bool AutoVacuumingActive(void);
! extern bool IsAutoVacuumProcess(void);
  
  /* Functions to start autovacuum process, called from postmaster */
  extern void autovac_init(void);
! extern int	autovac_start(void);
! extern void autovac_stopped(void);
  
  #ifdef EXEC_BACKEND
! extern void AutoVacMain(int argc, char *argv[]);
! extern void AutovacuumIAm(void);
  #endif
  
  #endif   /* AUTOVACUUM_H */
--- 27,51 ----
  
  /* Status inquiry functions */
  extern bool AutoVacuumingActive(void);
! extern bool IsAutoVacuumLauncherProcess(void);
! extern bool IsAutoVacuumWorkerProcess(void);
  
  /* Functions to start autovacuum process, called from postmaster */
  extern void autovac_init(void);
! extern int	StartAutoVacLauncher(void);
! extern int	StartAutoVacWorker(void);
  
  #ifdef EXEC_BACKEND
! extern void AutoVacLauncherMain(int argc, char *argv[]);
! extern void AutoVacWorkerMain(int argc, char *argv[]);
! extern void AutovacuumWorkerIAm(void);
! extern void AutovacuumLauncherIAm(void);
  #endif
  
+ /* shared memory stuff */
+ extern Size AutoVacuumShmemSize(void);
+ extern void AutoVacuumShmemInit(void);
+ 
+ extern MemoryContext AutoVacGetStatsContext(void);
+ 
  #endif   /* AUTOVACUUM_H */
Index: src/include/storage/lwlock.h
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/include/storage/lwlock.h,v
retrieving revision 1.33
diff -c -p -r1.33 lwlock.h
*** src/include/storage/lwlock.h	5 Jan 2007 22:19:58 -0000	1.33
--- src/include/storage/lwlock.h	26 Jan 2007 16:39:14 -0000
*************** typedef enum LWLockId
*** 62,67 ****
--- 62,68 ----
  	BtreeVacuumLock,
  	AddinShmemInitLock,
  	FirstBufMappingLock,
+ 	AutovacuumLock,
  	FirstLockMgrLock = FirstBufMappingLock + NUM_BUFFER_PARTITIONS,
  
  	/* must be last except for MaxDynamicLWLock: */
Index: src/include/storage/pmsignal.h
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/include/storage/pmsignal.h,v
retrieving revision 1.16
diff -c -p -r1.16 pmsignal.h
*** src/include/storage/pmsignal.h	5 Jan 2007 22:19:58 -0000	1.16
--- src/include/storage/pmsignal.h	26 Jan 2007 23:10:59 -0000
*************** typedef enum
*** 26,32 ****
  	PMSIGNAL_WAKEN_CHILDREN,	/* send a SIGUSR1 signal to all backends */
  	PMSIGNAL_WAKEN_ARCHIVER,	/* send a NOTIFY signal to xlog archiver */
  	PMSIGNAL_ROTATE_LOGFILE,	/* send SIGUSR1 to syslogger to rotate logfile */
! 	PMSIGNAL_START_AUTOVAC,		/* start an autovacuum iteration */
  
  	NUM_PMSIGNALS				/* Must be last value of enum! */
  } PMSignalReason;
--- 26,33 ----
  	PMSIGNAL_WAKEN_CHILDREN,	/* send a SIGUSR1 signal to all backends */
  	PMSIGNAL_WAKEN_ARCHIVER,	/* send a NOTIFY signal to xlog archiver */
  	PMSIGNAL_ROTATE_LOGFILE,	/* send SIGUSR1 to syslogger to rotate logfile */
! 	PMSIGNAL_START_AUTOVAC_LAUNCHER, /* start an autovacuum launcher */
! 	PMSIGNAL_START_AUTOVAC_WORKER, /* start an autovacuum worker */
  
  	NUM_PMSIGNALS				/* Must be last value of enum! */
  } PMSignalReason;
Index: src/include/storage/proc.h
===================================================================
RCS file: /home/alvherre/cvs/pgsql/src/include/storage/proc.h,v
retrieving revision 1.93
diff -c -p -r1.93 proc.h
*** src/include/storage/proc.h	16 Jan 2007 13:28:57 -0000	1.93
--- src/include/storage/proc.h	26 Jan 2007 16:39:14 -0000
*************** typedef struct PROC_HDR
*** 121,127 ****
   * We set aside some extra PGPROC structures for "dummy" processes,
   * ie things that aren't full-fledged backends but need shmem access.
   */
! #define NUM_DUMMY_PROCS		2
  
  
  /* configurable options */
--- 121,127 ----
   * We set aside some extra PGPROC structures for "dummy" processes,
   * ie things that aren't full-fledged backends but need shmem access.
   */
! #define NUM_DUMMY_PROCS		3
  
  
  /* configurable options */