Index: contrib/ltree/ltree.sql.in
===================================================================
RCS file: /cvsroot/pgsql/contrib/ltree/ltree.sql.in,v
retrieving revision 1.10
diff -c -c -r1.10 ltree.sql.in
*** contrib/ltree/ltree.sql.in	27 Feb 2006 16:09:48 -0000	1.10
--- contrib/ltree/ltree.sql.in	26 Apr 2006 18:25:16 -0000
***************
*** 230,236 ****
  	RIGHTARG = ltree,
  	PROCEDURE = ltree_isparent,
          COMMUTATOR = '<@',
!         RESTRICT = contsel,
  	JOIN = contjoinsel
  );
  
--- 230,236 ----
  	RIGHTARG = ltree,
  	PROCEDURE = ltree_isparent,
          COMMUTATOR = '<@',
!         RESTRICT = parentsel,
  	JOIN = contjoinsel
  );
  
***************
*** 248,254 ****
  	RIGHTARG = ltree,
  	PROCEDURE = ltree_risparent,
          COMMUTATOR = '@>',
!         RESTRICT = contsel,
  	JOIN = contjoinsel
  );
  
--- 248,254 ----
  	RIGHTARG = ltree,
  	PROCEDURE = ltree_risparent,
          COMMUTATOR = '@>',
!         RESTRICT = parentsel,
  	JOIN = contjoinsel
  );
  
Index: src/backend/utils/adt/geo_selfuncs.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/geo_selfuncs.c,v
retrieving revision 1.27
diff -c -c -r1.27 geo_selfuncs.c
*** src/backend/utils/adt/geo_selfuncs.c	5 Mar 2006 15:58:42 -0000	1.27
--- src/backend/utils/adt/geo_selfuncs.c	26 Apr 2006 18:25:21 -0000
***************
*** 20,26 ****
  
  #include "utils/geo_decls.h"
  
- 
  /*
   *	Selectivity functions for geometric operators.	These are bogus -- unless
   *	we know the actual key distribution in the index, we can't make a good
--- 20,25 ----
***************
*** 93,95 ****
--- 92,95 ----
  {
  	PG_RETURN_FLOAT8(0.001);
  }
+ 
Index: src/backend/utils/adt/selfuncs.c
===================================================================
RCS file: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v
retrieving revision 1.199
diff -c -c -r1.199 selfuncs.c
*** src/backend/utils/adt/selfuncs.c	20 Apr 2006 17:50:18 -0000	1.199
--- src/backend/utils/adt/selfuncs.c	26 Apr 2006 18:25:28 -0000
***************
*** 4852,4854 ****
--- 4852,5033 ----
  
  	PG_RETURN_VOID();
  }
+ 
+ 
+ #define DEFAULT_PARENT_SEL 0.001
+ 
+ /*
+  *	parentsel - Selectivity of parent relationship for ltree data types.
+  */
+ Datum
+ parentsel(PG_FUNCTION_ARGS)
+ {
+ 	PlannerInfo *root = (PlannerInfo *) PG_GETARG_POINTER(0);
+ 	Oid			operator = PG_GETARG_OID(1);
+ 	List	   *args = (List *) PG_GETARG_POINTER(2);
+ 	int			varRelid = PG_GETARG_INT32(3);
+ 	VariableStatData vardata;
+ 	Node	   *other;
+ 	bool		varonleft;
+ 	Datum	   *values;
+ 	int			nvalues;
+ 	float4	   *numbers;
+ 	int			nnumbers;
+ 	double		selec = 0.0;
+ 
+ 	/*
+ 	 * If expression is not variable <@ something or something <@ variable,
+ 	 * then punt and return a default estimate.
+ 	 */
+ 	if (!get_restriction_variable(root, args, varRelid,
+ 								  &vardata, &other, &varonleft))
+ 		PG_RETURN_FLOAT8(DEFAULT_PARENT_SEL);
+ 
+ 	/*
+ 	 * If the something is a NULL constant, assume operator is strict and
+ 	 * return zero, ie, operator will never return TRUE.
+ 	 */
+ 	if (IsA(other, Const) &&
+ 		((Const *) other)->constisnull)
+ 	{
+ 		ReleaseVariableStats(vardata);
+ 		PG_RETURN_FLOAT8(0.0);
+ 	}
+ 
+ 	if (HeapTupleIsValid(vardata.statsTuple))
+ 	{
+ 		Form_pg_statistic stats;
+ 		double		mcvsum = 0.0;
+ 		double		mcvsel = 0.0;
+ 		double		hissel = 0.0;
+ 
+ 		stats = (Form_pg_statistic) GETSTRUCT(vardata.statsTuple);
+ 
+ 		if (IsA(other, Const))
+ 		{
+ 			/* Variable is being compared to a known non-null constant */
+ 			Datum		constval = ((Const *) other)->constvalue;
+ 			bool		match = false;
+ 			int			i;
+ 
+ 			/*
+ 			 * Is the constant "<@" to any of the column's most common values?
+ 			 */
+ 			if (get_attstatsslot(vardata.statsTuple,
+ 								 vardata.atttype, vardata.atttypmod,
+ 								 STATISTIC_KIND_MCV, InvalidOid,
+ 								 &values, &nvalues,
+ 								 &numbers, &nnumbers))
+ 			{
+ 				FmgrInfo	contproc;
+ 
+ 				fmgr_info(get_opcode(operator), &contproc);
+ 
+ 				for (i = 0; i < nvalues; i++)
+ 				{
+ 					/* be careful to apply operator right way 'round */
+ 					if (varonleft)
+ 						match = DatumGetBool(FunctionCall2(&contproc,
+ 														   values[i],
+ 														   constval));
+ 					else
+ 						match = DatumGetBool(FunctionCall2(&contproc,
+ 														   constval,
+ 														   values[i]));
+ 
+ 					/* calculate total selectivity of all most-common-values */
+ 					mcvsum += numbers[i];
+ 
+ 					/* calculate selectivity of matching most-common-values */
+ 					if (match)
+ 						mcvsel += numbers[i];
+ 				}
+ 			}
+ 			else
+ 			{
+ 				/* no most-common-values info available */
+ 				values = NULL;
+ 				numbers = NULL;
+ 				i = nvalues = nnumbers = 0;
+ 			}
+ 
+ 			free_attstatsslot(vardata.atttype, values, nvalues, NULL, 0);
+ 
+ 			/*
+ 			 * Is the constant "<@" to any of the column's histogram values?
+ 			 */
+ 			if (get_attstatsslot(vardata.statsTuple,
+ 								 vardata.atttype, vardata.atttypmod,
+ 								 STATISTIC_KIND_HISTOGRAM, InvalidOid,
+ 								 &values, &nvalues,
+ 								 NULL, NULL))
+ 			{
+ 				FmgrInfo	contproc;
+ 
+ 				fmgr_info(get_opcode(operator), &contproc);
+ 
+ 				for (i = 0; i < nvalues; i++)
+ 				{
+ 					/* be careful to apply operator right way 'round */
+ 					if (varonleft)
+ 						match = DatumGetBool(FunctionCall2(&contproc,
+ 														   values[i],
+ 														   constval));
+ 					else
+ 						match = DatumGetBool(FunctionCall2(&contproc,
+ 														   constval,
+ 														   values[i]));
+ 					/* count matching histogram values */
+ 					if (match)
+ 						hissel++;
+ 				}
+ 
+ 				if (hissel > 0.0)
+ 				{
+ 					/*
+ 					 * some matching values found inside histogram, divide
+ 					 * matching entries number by total histogram entries to
+ 					 * get the histogram related selectivity
+ 					 */
+ 					hissel /= nvalues;
+ 				}
+ 			}
+ 			else
+ 			{
+ 				/* no histogram info available */
+ 				values = NULL;
+ 				i = nvalues = 0;
+ 			}
+ 
+ 			free_attstatsslot(vardata.atttype, values, nvalues,
+ 							  NULL, 0);
+ 
+ 
+ 			/*
+ 			 * calculate selectivity based on MCV and histogram result
+ 			 * histogram selectivity needs to be scaled down if there are any
+ 			 * most-common-values
+ 			 */
+ 			selec = mcvsel + hissel * (1.0 - mcvsum);
+ 
+ 			/*
+ 			 * don't return 0.0 selectivity unless all table values are inside
+ 			 * mcv
+ 			 */
+ 			if (selec == 0.0 && mcvsum != 1.0)
+ 				selec = DEFAULT_PARENT_SEL;
+ 		}
+ 		else
+ 			selec = DEFAULT_PARENT_SEL;
+ 	}
+ 	else
+ 		selec = DEFAULT_PARENT_SEL;
+ 
+ 	ReleaseVariableStats(vardata);
+ 
+ 	/* result should be in range, but make sure... */
+ 	CLAMP_PROBABILITY(selec);
+ 
+ 	PG_RETURN_FLOAT8((float8) selec);
+ }
+ 
Index: src/include/catalog/pg_proc.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/catalog/pg_proc.h,v
retrieving revision 1.406
diff -c -c -r1.406 pg_proc.h
*** src/include/catalog/pg_proc.h	25 Apr 2006 00:25:20 -0000	1.406
--- src/include/catalog/pg_proc.h	26 Apr 2006 18:25:35 -0000
***************
*** 3812,3817 ****
--- 3812,3819 ----
  DESCR("GiST support");
  DATA(insert OID = 2592 (  gist_circle_compress	PGNSP PGUID 12 f f t f i 1 2281 "2281" _null_ _null_ _null_ gist_circle_compress - _null_ ));
  DESCR("GiST support");
+ DATA(insert OID = 2599 (  parentsel              PGNSP PGUID 12 f f t f s 4 701 "2281 26 2281 23" _null_ _null_ _null_ parentsel - _null_ ));
+ DESCR("enhanced restriction selectivity for ltree isparent comparison operators");
  
  
  /*
Index: src/include/utils/selfuncs.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/utils/selfuncs.h,v
retrieving revision 1.28
diff -c -c -r1.28 selfuncs.h
*** src/include/utils/selfuncs.h	5 Mar 2006 15:59:07 -0000	1.28
--- src/include/utils/selfuncs.h	26 Apr 2006 18:25:35 -0000
***************
*** 134,137 ****
--- 134,139 ----
  extern Datum hashcostestimate(PG_FUNCTION_ARGS);
  extern Datum gistcostestimate(PG_FUNCTION_ARGS);
  
+ extern Datum parentsel(PG_FUNCTION_ARGS);
+ 
  #endif   /* SELFUNCS_H */