Index: src/backend/storage/ipc/sinval.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/storage/ipc/sinval.c,v
retrieving revision 1.63
diff -c -r1.63 sinval.c
*** src/backend/storage/ipc/sinval.c	23 May 2004 03:50:45 -0000	1.63
--- src/backend/storage/ipc/sinval.c	24 May 2004 19:25:16 -0000
***************
*** 464,469 ****
--- 464,503 ----
  }
  
  /*
+  * IsBackendPid -- is a given pid a running backend
+  */
+ bool
+ IsBackendPid(int pid)
+ {
+ 	bool		result = false;
+ 	SISeg	   *segP = shmInvalBuffer;
+ 	ProcState  *stateP = segP->procState;
+ 	int			index;
+ 
+ 	LWLockAcquire(SInvalLock, LW_SHARED);
+ 
+ 	for (index = 0; index < segP->lastBackend; index++)
+ 	{
+ 		SHMEM_OFFSET pOffset = stateP[index].procStruct;
+ 
+ 		if (pOffset != INVALID_OFFSET)
+ 		{
+ 			PGPROC	   *proc = (PGPROC *) MAKE_PTR(pOffset);
+ 
+ 			if (proc->pid == pid)
+ 			{
+ 				result = true;
+ 				break;
+ 			}
+ 		}
+ 	}
+ 
+ 	LWLockRelease(SInvalLock);
+ 
+ 	return result;
+ }
+ 
+ /*
   * GetOldestXmin -- returns oldest transaction that was running
   *					when any current transaction was started.
   *
Index: src/backend/utils/adt/misc.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/utils/adt/misc.c,v
retrieving revision 1.33
diff -c -r1.33 misc.c
*** src/backend/utils/adt/misc.c	21 May 2004 05:08:02 -0000	1.33
--- src/backend/utils/adt/misc.c	24 May 2004 19:12:47 -0000
***************
*** 15,20 ****
--- 15,21 ----
  #include "postgres.h"
  
  #include <sys/file.h>
+ #include <signal.h>
  
  #include "commands/dbcommands.h"
  #include "miscadmin.h"
***************
*** 56,59 ****
--- 57,104 ----
  
  	namestrcpy(db, get_database_name(MyDatabaseId));
  	PG_RETURN_NAME(db);
+ }
+ 
+ 
+ /*
+  * Functions to terminate a backend or cancel a query running on
+  * a different backend.
+  */
+ 
+ static int pg_signal_backend(int pid, int sig) 
+ {
+ 	if (!superuser()) 
+ 		ereport(ERROR,
+ 				(errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ 				 (errmsg("only superuser can signal other backends"))));
+ 	
+ 	if (!IsBackendPid(pid))
+ 	{
+ 		/* This is just a warning so a loop-through-resultset will not abort
+ 		 * if one backend terminated on it's own during the run */
+ 		ereport(WARNING,
+ 				(errmsg("pid %i is not a postgresql backend",pid)));
+ 		return 0;
+ 	}
+ 
+ 	if (kill(pid, sig)) 
+ 	{
+ 		/* Again, just a warning to allow loops */
+ 		ereport(WARNING,
+ 				(errmsg("failed to send signal to backend %i: %m",pid)));
+ 		return 0;
+ 	}
+ 	return 1;
+ }
+ 
+ Datum
+ pg_terminate_backend(PG_FUNCTION_ARGS)
+ {
+ 	PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0),SIGTERM));
+ }
+ 
+ Datum
+ pg_cancel_backend(PG_FUNCTION_ARGS)
+ {
+ 	PG_RETURN_INT32(pg_signal_backend(PG_GETARG_INT32(0),SIGINT));
  }
Index: src/include/catalog/pg_proc.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/catalog/pg_proc.h,v
retrieving revision 1.333
diff -c -r1.333 pg_proc.h
*** src/include/catalog/pg_proc.h	26 May 2004 18:37:33 -0000	1.333
--- src/include/catalog/pg_proc.h	27 May 2004 17:38:16 -0000
***************
*** 2808,2813 ****
--- 2808,2818 ----
  DATA(insert OID = 1945 (  pg_stat_get_db_blocks_hit		PGNSP PGUID 12 f f t f s 1 20 "26" _null_	pg_stat_get_db_blocks_hit - _null_ ));
  DESCR("Statistics: Blocks found in cache for database");
  
+ DATA(insert OID = 2171 ( pg_terminate_backend           PGNSP PGUID 12 f f t f s 1 23 "23" _null_ pg_terminate_backend - _null_ ));
+ DESCR("Terminate a backend process");
+ DATA(insert OID = 2172 ( pg_cancel_backend              PGNSP PGUID 12 f f t f s 1 23 "23" _null_ pg_cancel_backend - _null_ ));
+ DESCR("Cancel running query on a backend process");
+ 
  DATA(insert OID = 1946 (  encode						PGNSP PGUID 12 f f t f i 2 25 "17 25" _null_  binary_encode - _null_ ));
  DESCR("Convert bytea value into some ascii-only text string");
  DATA(insert OID = 1947 (  decode						PGNSP PGUID 12 f f t f i 2 17 "25 25" _null_  binary_decode - _null_ ));
Index: src/include/storage/sinval.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/storage/sinval.h,v
retrieving revision 1.34
diff -c -r1.34 sinval.h
*** src/include/storage/sinval.h	23 May 2004 03:50:45 -0000	1.34
--- src/include/storage/sinval.h	24 May 2004 18:59:17 -0000
***************
*** 97,102 ****
--- 97,103 ----
  
  extern bool DatabaseHasActiveBackends(Oid databaseId, bool ignoreMyself);
  extern bool TransactionIdIsInProgress(TransactionId xid);
+ extern bool IsBackendPid(int pid);
  extern TransactionId GetOldestXmin(bool allDbs);
  extern int	CountActiveBackends(void);
  extern int	CountEmptyBackendSlots(void);
Index: src/include/utils/builtins.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/utils/builtins.h,v
retrieving revision 1.240
diff -c -r1.240 builtins.h
*** src/include/utils/builtins.h	26 May 2004 18:35:46 -0000	1.240
--- src/include/utils/builtins.h	27 May 2004 17:38:16 -0000
***************
*** 354,359 ****
--- 354,361 ----
  extern Datum nullvalue(PG_FUNCTION_ARGS);
  extern Datum nonnullvalue(PG_FUNCTION_ARGS);
  extern Datum current_database(PG_FUNCTION_ARGS);
+ extern Datum pg_terminate_backend(PG_FUNCTION_ARGS);
+ extern Datum pg_cancel_backend(PG_FUNCTION_ARGS);
  
  /* not_in.c */
  extern Datum int4notin(PG_FUNCTION_ARGS);