Finish repairing 6.5's problems with r-tree indexes: create appropriate

selectivity functions and make the r-tree operators use them.  The
estimation functions themselves are just stubs, unfortunately, but
perhaps someday someone will make them compute realistic estimates.
Change pg_am so that the optimizer can reliably tell the difference
between ordered and unordered indexes --- before it would think that
an r-tree index can be scanned in '<<' order, which is not right AFAIK.
Repair broken negator links for network_sup and related ops.
Initdb forced.  This might be my last initdb force for 7.0 ... hope so
anyway ...

src/backend/optimizer/util/plancat.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.47 2000/02/15 20:49:20 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/plancat.c,v 1.48 2000/02/17 03:39:40 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -96,8 +96,8 @@ find_secondary_indexes(Query *root, Index relid)
 		IndexOptInfo   *info = makeNode(IndexOptInfo);
 		int				i;
 		Relation		indexRelation;
-		uint16			amstrategy;
 		Oid				relam;
+		uint16			amorderstrategy;
 
 		/*
 		 * Need to make these arrays large enough to be sure there is a
@@ -129,37 +129,38 @@ find_secondary_indexes(Query *root, Index relid)
 
 		/* Extract info from the relation descriptor for the index */
 		indexRelation = index_open(index->indexrelid);
-#ifdef notdef
-		/* XXX should iterate through strategies -- but how?  use #1 for now */
-		amstrategy = indexRelation->rd_am->amstrategies;
-#endif	 /* notdef */
-		amstrategy = 1;
 		relam = indexRelation->rd_rel->relam;
 		info->relam = relam;
 		info->pages = indexRelation->rd_rel->relpages;
 		info->tuples = indexRelation->rd_rel->reltuples;
 		info->amcostestimate = index_cost_estimator(indexRelation);
+		amorderstrategy = indexRelation->rd_am->amorderstrategy;
 		index_close(indexRelation);
 
 		/*
-		 * Fetch the ordering operators associated with the index.
-		 *
-		 * XXX what if it's a hash or other unordered index?
+		 * Fetch the ordering operators associated with the index,
+		 * if any.
 		 */
 		MemSet(info->ordering, 0, sizeof(Oid) * (INDEX_MAX_KEYS+1));
-		for (i = 0; i < INDEX_MAX_KEYS && index->indclass[i]; i++)
+		if (amorderstrategy != 0)
 		{
-			HeapTuple		amopTuple;
+			for (i = 0; i < INDEX_MAX_KEYS && index->indclass[i]; i++)
+			{
+				HeapTuple		amopTuple;
+				Form_pg_amop	amop;
 
-			amopTuple = SearchSysCacheTuple(AMOPSTRATEGY,
+				amopTuple =
+					SearchSysCacheTuple(AMOPSTRATEGY,
 										ObjectIdGetDatum(relam),
 										ObjectIdGetDatum(index->indclass[i]),
-										UInt16GetDatum(amstrategy),
+										UInt16GetDatum(amorderstrategy),
 										0);
-			if (!HeapTupleIsValid(amopTuple))
-				elog(ERROR, "find_secondary_indexes: no amop %u %u %d",
-					 relam, index->indclass[i], amstrategy);
-			info->ordering[i] = ((Form_pg_amop) GETSTRUCT(amopTuple))->amopopr;
+				if (!HeapTupleIsValid(amopTuple))
+					elog(ERROR, "find_secondary_indexes: no amop %u %u %d",
+						 relam, index->indclass[i], (int) amorderstrategy);
+				amop = (Form_pg_amop) GETSTRUCT(amopTuple);
+				info->ordering[i] = amop->amopopr;
+			}
 		}
 
 		indexes = lcons(info, indexes);

src/backend/utils/adt/geo_selfuncs.c

@@ -1,6 +1,6 @@
 /*-------------------------------------------------------------------------
  *
- * geo-selfuncs.c
+ * geo_selfuncs.c
  *	  Selectivity routines registered in the operator catalog in the
  *	  "oprrest" and "oprjoin" attributes.
  *
@@ -9,9 +9,10 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_selfuncs.c,v 1.12 2000/01/26 05:57:14 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/adt/geo_selfuncs.c,v 1.13 2000/02/17 03:39:42 tgl Exp $
  *
- *		XXX These are totally bogus.
+ *	XXX These are totally bogus.  Perhaps someone will make them do
+ *	something reasonable, someday.
  *
  *-------------------------------------------------------------------------
  */
@@ -19,17 +20,41 @@
 
 #include "utils/builtins.h"
 
+
+/*
+ *	Selectivity functions for rtrees.  These are bogus -- unless we know
+ *	the actual key distribution in the index, we can't make a good prediction
+ *	of the selectivity of these operators.
+ *
+ *	Note: the values used here may look unreasonably small.  Perhaps they
+ *	are.  For now, we want to make sure that the optimizer will make use
+ *	of an r-tree index if one is available, so the selectivity had better
+ *	be fairly small.
+ *
+ *	In general, rtrees need to search multiple subtrees in order to guarantee
+ *	that all occurrences of the same key have been found.  Because of this,
+ *	the estimated cost for scanning the index ought to be higher than the
+ *	output selectivity would indicate.  rtcostestimate(), over in selfuncs.c,
+ *	ought to be adjusted accordingly --- but until we can generate somewhat
+ *	realistic numbers here, it hardly matters...
+ */
+
+
+/*
+ * Selectivity for operators that depend on area, such as "overlap".
+ */
+
 float64
 areasel(Oid opid,
 		Oid relid,
 		AttrNumber attno,
-		char *value,
+		Datum value,
 		int32 flag)
 {
 	float64		result;
 
 	result = (float64) palloc(sizeof(float64data));
-	*result = 1.0 / 4.0;
+	*result = 0.05;
 	return result;
 }
 
@@ -43,81 +68,66 @@ areajoinsel(Oid opid,
 	float64		result;
 
 	result = (float64) palloc(sizeof(float64data));
-	*result = 1.0 / 4.0;
+	*result = 0.05;
 	return result;
 }
 
 /*
- *	Selectivity functions for rtrees.  These are bogus -- unless we know
- *	the actual key distribution in the index, we can't make a good prediction
- *	of the selectivity of these operators.
+ *	positionsel
  *
- *	In general, rtrees need to search multiple subtrees in order to guarantee
- *	that all occurrences of the same key have been found.  Because of this,
- *	the heuristic selectivity functions we return are higher than they would
- *	otherwise be.
+ * How likely is a box to be strictly left of (right of, above, below)
+ * a given box?
  */
 
-/*
- *	left_sel -- How likely is a box to be strictly left of (right of, above,
- *				below) a given box?
- */
-
-#ifdef NOT_USED
 float64
-leftsel(Oid opid,
-		Oid relid,
-		AttrNumber attno,
-		char *value,
-		int32 flag)
+positionsel(Oid opid,
+			Oid relid,
+			AttrNumber attno,
+			Datum value,
+			int32 flag)
 {
 	float64		result;
 
 	result = (float64) palloc(sizeof(float64data));
-	*result = 1.0 / 6.0;
+	*result = 0.1;
 	return result;
 }
 
-#endif
-
-#ifdef NOT_USED
 float64
-leftjoinsel(Oid opid,
-			Oid relid1,
-			AttrNumber attno1,
-			Oid relid2,
-			AttrNumber attno2)
+positionjoinsel(Oid opid,
+				Oid relid1,
+				AttrNumber attno1,
+				Oid relid2,
+				AttrNumber attno2)
 {
 	float64		result;
 
 	result = (float64) palloc(sizeof(float64data));
-	*result = 1.0 / 6.0;
+	*result = 0.1;
 	return result;
 }
 
-#endif
-
 /*
  *	contsel -- How likely is a box to contain (be contained by) a given box?
+ *
+ * This is a tighter constraint than "overlap", so produce a smaller
+ * estimate than areasel does.
  */
-#ifdef NOT_USED
+
 float64
 contsel(Oid opid,
 		Oid relid,
 		AttrNumber attno,
-		char *value,
+		Datum value,
 		int32 flag)
 {
 	float64		result;
 
 	result = (float64) palloc(sizeof(float64data));
-	*result = 1.0 / 10.0;
+	*result = 0.01;
 	return result;
 }
 
-#endif
-
-#ifdef NOT_USED
 float64
 contjoinsel(Oid opid,
 			Oid relid1,
@@ -128,8 +138,6 @@ contjoinsel(Oid opid,
 	float64		result;
 
 	result = (float64) palloc(sizeof(float64data));
-	*result = 1.0 / 10.0;
+	*result = 0.01;
 	return result;
 }
-
-#endif