Adjust indexscan planning logic to keep RestrictInfo nodes associated

with index qual clauses in the Path representation.  This saves a little
work during createplan and (probably more importantly) allows reuse of
cached selectivity estimates during indexscan planning.  Also fix latent
bug: wrong plan would have been generated for a 'special operator' used
in a nestloop-inner-indexscan join qual, because the special operator
would not have gotten into the list of quals to recheck.  This bug is
only latent because at present the special-operator code could never
trigger on a join qual, but sooner or later someone will want to do it.

src/backend/nodes/outfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.227 2004/01/05 18:04:38 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.228 2004/01/05 23:39:53 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -968,8 +968,9 @@ _outIndexPath(StringInfo str, IndexPath *node)
 	_outPathInfo(str, (Path *) node);
 
 	WRITE_NODE_FIELD(indexinfo);
-	WRITE_NODE_FIELD(indexqual);
-	WRITE_NODE_FIELD(indexjoinclauses);
+	WRITE_NODE_FIELD(indexclauses);
+	WRITE_NODE_FIELD(indexquals);
+	WRITE_BOOL_FIELD(isjoininner);
 	WRITE_ENUM_FIELD(indexscandir, ScanDirection);
 	WRITE_FLOAT_FIELD(rows, "%.0f");
 }

src/backend/optimizer/path/costsize.c

@@ -49,7 +49,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.120 2004/01/05 05:07:35 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.121 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -238,6 +238,9 @@ cost_nonsequential_access(double relpages)
  * Any additional quals evaluated as qpquals may reduce the number of returned
  * tuples, but they won't reduce the number of tuples we have to fetch from
  * the table, so they don't reduce the scan cost.
+ *
+ * NOTE: as of 7.5, indexQuals is a list of RestrictInfo nodes, where formerly
+ * it was a list of bare clause expressions.
  */
 void
 cost_index(Path *path, Query *root,

src/backend/optimizer/path/indxpath.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.154 2004/01/05 05:07:35 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.155 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -76,7 +76,7 @@ static bool match_index_to_operand(Node *operand, int indexcol,
 					   RelOptInfo *rel, IndexOptInfo *index);
 static bool match_special_index_operator(Expr *clause, Oid opclass,
 							 bool indexkey_on_left);
-static List *expand_indexqual_condition(Expr *clause, Oid opclass);
+static List *expand_indexqual_condition(RestrictInfo *rinfo, Oid opclass);
 static List *prefix_quals(Node *leftop, Oid opclass,
 			 Const *prefix, Pattern_Prefix_Status pstatus);
 static List *network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass,
@@ -1418,8 +1418,7 @@ make_innerjoin_index_path(Query *root,
 {
 	IndexPath  *pathnode = makeNode(IndexPath);
 	List	   *indexquals,
-			   *allclauses,
-			   *l;
+			   *allclauses;
 
 	/* XXX perhaps this code should be merged with create_index_path? */
 
@@ -1433,28 +1432,21 @@ make_innerjoin_index_path(Query *root,
 	 */
 	pathnode->path.pathkeys = NIL;
 
-	/* Convert RestrictInfo nodes to indexquals the executor can handle */
+	/* Convert clauses to indexquals the executor can handle */
 	indexquals = expand_indexqual_conditions(index, clausegroups);
 
-	/*
-	 * Also make a flattened list of the RestrictInfo nodes; createplan.c
-	 * will need this later.  We assume here that we can destructively
-	 * modify the passed-in clausegroups list structure.
-	 */
-	allclauses = NIL;
-	foreach(l, clausegroups)
-	{
-		/* nconc okay here since same clause couldn't be in two sublists */
-		allclauses = nconc(allclauses, (List *) lfirst(l));
-	}
+	/* Flatten the clausegroups list to produce indexclauses list */
+	allclauses = flatten_clausegroups_list(clausegroups);
 
 	/*
 	 * Note that we are making a pathnode for a single-scan indexscan;
-	 * therefore, indexinfo and indexqual should be single-element lists.
+	 * therefore, indexinfo etc should be single-element lists.
 	 */
 	pathnode->indexinfo = makeList1(index);
-	pathnode->indexqual = makeList1(indexquals);
-	pathnode->indexjoinclauses = makeList1(allclauses);
+	pathnode->indexclauses = makeList1(allclauses);
+	pathnode->indexquals = makeList1(indexquals);
+
+	pathnode->isjoininner = true;
 
 	/* We don't actually care what order the index scans in ... */
 	pathnode->indexscandir = NoMovementScanDirection;
@@ -1489,6 +1481,61 @@ make_innerjoin_index_path(Query *root,
 	return (Path *) pathnode;
 }
 
+/*
+ * flatten_clausegroups_list
+ *	  Given a list of lists of RestrictInfos, flatten it to a list
+ *	  of RestrictInfos.
+ *
+ * This is used to flatten out the result of group_clauses_by_indexkey()
+ * or one of its sibling routines, to produce an indexclauses list.
+ */
+List *
+flatten_clausegroups_list(List *clausegroups)
+{
+	List	   *allclauses = NIL;
+	List	   *l;
+
+	foreach(l, clausegroups)
+	{
+		allclauses = nconc(allclauses, listCopy((List *) lfirst(l)));
+	}
+	return allclauses;
+}
+
+/*
+ * make_expr_from_indexclauses()
+ *	  Given an indexclauses structure, produce an ordinary boolean expression.
+ *
+ * This consists of stripping out the RestrictInfo nodes and inserting
+ * explicit AND and OR nodes as needed.  There's not much to it, but
+ * the functionality is needed in a few places, so centralize the logic.
+ */
+Expr *
+make_expr_from_indexclauses(List *indexclauses)
+{
+	List	   *orclauses = NIL;
+	List	   *orlist;
+
+	/* There's no such thing as an indexpath with zero scans */
+	Assert(indexclauses != NIL);
+
+	foreach(orlist, indexclauses)
+	{
+		List   *andlist = (List *) lfirst(orlist);
+
+		/* Strip RestrictInfos */
+		andlist = get_actual_clauses(andlist);
+		/* Insert AND node if needed, and add to orclauses list */
+		orclauses = lappend(orclauses, make_ands_explicit(andlist));
+	}
+
+	if (length(orclauses) > 1)
+		return make_orclause(orclauses);
+	else
+		return (Expr *) lfirst(orclauses);
+}
+
+
 /****************************************************************************
  *				----  ROUTINES TO CHECK OPERANDS  ----
  ****************************************************************************/
@@ -1799,8 +1846,7 @@ expand_indexqual_conditions(IndexOptInfo *index, List *clausegroups)
 			RestrictInfo *rinfo = (RestrictInfo *) lfirst(i);
 
 			FastConc(&resultquals,
-					 expand_indexqual_condition(rinfo->clause,
-												curClass));
+					 expand_indexqual_condition(rinfo, curClass));
 		}
 
 		clausegroups = lnext(clausegroups);
@@ -1816,10 +1862,13 @@ expand_indexqual_conditions(IndexOptInfo *index, List *clausegroups)
 
 /*
  * expand_indexqual_condition --- expand a single indexqual condition
+ *
+ * The input is a single RestrictInfo, the output a list of RestrictInfos
  */
 static List *
-expand_indexqual_condition(Expr *clause, Oid opclass)
+expand_indexqual_condition(RestrictInfo *rinfo, Oid opclass)
 {
+	Expr	   *clause = rinfo->clause;
 	/* we know these will succeed */
 	Node	   *leftop = get_leftop(clause);
 	Node	   *rightop = get_rightop(clause);
@@ -1883,7 +1932,7 @@ expand_indexqual_condition(Expr *clause, Oid opclass)
 			break;
 
 		default:
-			result = makeList1(clause);
+			result = makeList1(rinfo);
 			break;
 	}
 
@@ -1978,7 +2027,7 @@ prefix_quals(Node *leftop, Oid opclass,
 			elog(ERROR, "no = operator for opclass %u", opclass);
 		expr = make_opclause(oproid, BOOLOID, false,
 							 (Expr *) leftop, (Expr *) prefix_const);
-		result = makeList1(expr);
+		result = makeList1(make_restrictinfo(expr, true, true));
 		return result;
 	}
 
@@ -1993,7 +2042,7 @@ prefix_quals(Node *leftop, Oid opclass,
 		elog(ERROR, "no >= operator for opclass %u", opclass);
 	expr = make_opclause(oproid, BOOLOID, false,
 						 (Expr *) leftop, (Expr *) prefix_const);
-	result = makeList1(expr);
+	result = makeList1(make_restrictinfo(expr, true, true));
 
 	/*-------
 	 * If we can create a string larger than the prefix, we can say
@@ -2009,7 +2058,7 @@ prefix_quals(Node *leftop, Oid opclass,
 			elog(ERROR, "no < operator for opclass %u", opclass);
 		expr = make_opclause(oproid, BOOLOID, false,
 							 (Expr *) leftop, (Expr *) greaterstr);
-		result = lappend(result, expr);
+		result = lappend(result, make_restrictinfo(expr, true, true));
 	}
 
 	return result;
@@ -2080,7 +2129,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
 						 (Expr *) leftop,
 						 (Expr *) makeConst(datatype, -1, opr1right,
 											false, false));
-	result = makeList1(expr);
+	result = makeList1(make_restrictinfo(expr, true, true));
 
 	/* create clause "key <= network_scan_last( rightop )" */
 
@@ -2095,7 +2144,7 @@ network_prefix_quals(Node *leftop, Oid expr_op, Oid opclass, Datum rightop)
 						 (Expr *) leftop,
 						 (Expr *) makeConst(datatype, -1, opr2right,
 											false, false));
-	result = lappend(result, expr);
+	result = lappend(result, make_restrictinfo(expr, true, true));
 
 	return result;
 }

src/backend/optimizer/path/orindxpath.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.56 2004/01/05 05:07:35 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.57 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -28,7 +28,8 @@ static bool best_or_subclause_index(Query *root,
 						RelOptInfo *rel,
 						Expr *subclause,
 						IndexOptInfo **retIndexInfo,
-						List **retIndexQual,
+						List **retIndexClauses,
+						List **retIndexQuals,
 						Cost *retStartupCost,
 						Cost *retTotalCost);
 
@@ -95,9 +96,7 @@ create_or_index_quals(Query *root, RelOptInfo *rel)
 {
 	IndexPath  *bestpath = NULL;
 	RestrictInfo *bestrinfo = NULL;
-	FastList	orclauses;
-	List	   *orclause;
-	Expr	   *indxqual_or_expr;
+	List	   *newrinfos;
 	RestrictInfo *or_rinfo;
 	Selectivity or_selec,
 				orig_selec;
@@ -145,20 +144,14 @@ create_or_index_quals(Query *root, RelOptInfo *rel)
 		return false;
 
 	/*
-	 * Build an expression representation of the indexqual, expanding
-	 * the implicit OR and AND semantics of the first- and
-	 * second-level lists.
+	 * Convert the indexclauses structure to a RestrictInfo tree,
+	 * and add it to the rel's restriction list.
 	 */
-	FastListInit(&orclauses);
-	foreach(orclause, bestpath->indexqual)
-		FastAppend(&orclauses, make_ands_explicit(lfirst(orclause)));
-	indxqual_or_expr = make_orclause(FastListValue(&orclauses));
-
-	/*
-	 * And add it to the rel's restriction list.
-	 */
-	or_rinfo = make_restrictinfo(indxqual_or_expr, true, true);
-	rel->baserestrictinfo = lappend(rel->baserestrictinfo, or_rinfo);
+	newrinfos = make_restrictinfo_from_indexclauses(bestpath->indexclauses,
+													true, true);
+	Assert(length(newrinfos) == 1);
+	or_rinfo = (RestrictInfo *) lfirst(newrinfos);
+	rel->baserestrictinfo = nconc(rel->baserestrictinfo, newrinfos);
 
 	/*
 	 * Adjust the original OR clause's cached selectivity to compensate
@@ -251,6 +244,7 @@ best_or_subclause_indexes(Query *root,
 						  List *subclauses)
 {
 	FastList	infos;
+	FastList	clauses;
 	FastList	quals;
 	Cost		path_startup_cost;
 	Cost		path_total_cost;
@@ -258,6 +252,7 @@ best_or_subclause_indexes(Query *root,
 	IndexPath  *pathnode;
 
 	FastListInit(&infos);
+	FastListInit(&clauses);
 	FastListInit(&quals);
 	path_startup_cost = 0;
 	path_total_cost = 0;
@@ -267,17 +262,20 @@ best_or_subclause_indexes(Query *root,
 	{
 		Expr	   *subclause = lfirst(slist);
 		IndexOptInfo *best_indexinfo;
-		List	   *best_indexqual;
+		List	   *best_indexclauses;
+		List	   *best_indexquals;
 		Cost		best_startup_cost;
 		Cost		best_total_cost;
 
 		if (!best_or_subclause_index(root, rel, subclause,
-									 &best_indexinfo, &best_indexqual,
+									 &best_indexinfo,
+									 &best_indexclauses, &best_indexquals,
 									 &best_startup_cost, &best_total_cost))
 			return NULL;		/* failed to match this subclause */
 
 		FastAppend(&infos, best_indexinfo);
-		FastAppend(&quals, best_indexqual);
+		FastAppend(&clauses, best_indexclauses);
+		FastAppend(&quals, best_indexquals);
 		/*
 		 * Path startup_cost is the startup cost for the first index scan only;
 		 * startup costs for later scans will be paid later on, so they just
@@ -306,10 +304,11 @@ best_or_subclause_indexes(Query *root,
 	pathnode->path.pathkeys = NIL;
 
 	pathnode->indexinfo = FastListValue(&infos);
-	pathnode->indexqual = FastListValue(&quals);
+	pathnode->indexclauses = FastListValue(&clauses);
+	pathnode->indexquals = FastListValue(&quals);
 
 	/* It's not an innerjoin path. */
-	pathnode->indexjoinclauses = NIL;
+	pathnode->isjoininner = false;
 
 	/* We don't actually care what order the index scans in. */
 	pathnode->indexscandir = NoMovementScanDirection;
@@ -336,7 +335,8 @@ best_or_subclause_indexes(Query *root,
  * 'subclause' is the OR subclause being considered
  *
  * '*retIndexInfo' gets the IndexOptInfo of the best index
- * '*retIndexQual' gets a list of the indexqual conditions for the best index
+ * '*retIndexClauses' gets a list of the index clauses for the best index
+ * '*retIndexQuals' gets a list of the expanded indexquals for the best index
  * '*retStartupCost' gets the startup cost of a scan with that index
  * '*retTotalCost' gets the total cost of a scan with that index
  */
@@ -345,7 +345,8 @@ best_or_subclause_index(Query *root,
 						RelOptInfo *rel,
 						Expr *subclause,
 						IndexOptInfo **retIndexInfo,	/* return value */
-						List **retIndexQual,	/* return value */
+						List **retIndexClauses,	/* return value */
+						List **retIndexQuals,	/* return value */
 						Cost *retStartupCost,	/* return value */
 						Cost *retTotalCost)		/* return value */
 {
@@ -355,7 +356,7 @@ best_or_subclause_index(Query *root,
 	foreach(ilist, rel->indexlist)
 	{
 		IndexOptInfo *index = (IndexOptInfo *) lfirst(ilist);
-		List	   *qualrinfos;
+		List	   *indexclauses;
 		List	   *indexquals;
 		Path		subclause_path;
 
@@ -364,21 +365,22 @@ best_or_subclause_index(Query *root,
 			continue;
 
 		/* Collect index clauses usable with this index */
-		qualrinfos = group_clauses_by_indexkey_for_or(rel, index, subclause);
+		indexclauses = group_clauses_by_indexkey_for_or(rel, index, subclause);
 
 		/* Ignore index if it doesn't match the subclause at all */
-		if (qualrinfos == NIL)
+		if (indexclauses == NIL)
 			continue;
 
-		/* Convert RestrictInfo nodes to indexquals the executor can handle */
-		indexquals = expand_indexqual_conditions(index, qualrinfos);
+		/* Convert clauses to indexquals the executor can handle */
+		indexquals = expand_indexqual_conditions(index, indexclauses);
 
 		cost_index(&subclause_path, root, rel, index, indexquals, false);
 
 		if (!found || subclause_path.total_cost < *retTotalCost)
 		{
 			*retIndexInfo = index;
-			*retIndexQual = indexquals;
+			*retIndexClauses = flatten_clausegroups_list(indexclauses);
+			*retIndexQuals = indexquals;
 			*retStartupCost = subclause_path.startup_cost;
 			*retTotalCost = subclause_path.total_cost;
 			found = true;

src/backend/optimizer/util/pathnode.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.98 2004/01/05 18:04:39 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/pathnode.c,v 1.99 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -354,18 +354,22 @@ create_index_path(Query *root,
 	pathnode->path.parent = rel;
 	pathnode->path.pathkeys = pathkeys;
 
-	/* Convert RestrictInfo nodes to indexquals the executor can handle */
+	/* Convert clauses to indexquals the executor can handle */
 	indexquals = expand_indexqual_conditions(index, restriction_clauses);
 
+	/* Flatten the clause-groups list to produce indexclauses list */
+	restriction_clauses = flatten_clausegroups_list(restriction_clauses);
+
 	/*
 	 * We are making a pathnode for a single-scan indexscan; therefore,
-	 * both indexinfo and indexqual should be single-element lists.
+	 * indexinfo etc should be single-element lists.
 	 */
 	pathnode->indexinfo = makeList1(index);
-	pathnode->indexqual = makeList1(indexquals);
+	pathnode->indexclauses = makeList1(restriction_clauses);
+	pathnode->indexquals = makeList1(indexquals);
 
 	/* It's not an innerjoin path. */
-	pathnode->indexjoinclauses = NIL;
+	pathnode->isjoininner = false;
 
 	pathnode->indexscandir = indexscandir;
 

src/backend/optimizer/util/restrictinfo.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.24 2004/01/05 05:07:36 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.25 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,7 +20,12 @@
 #include "optimizer/var.h"
 
 
-static Expr *make_sub_restrictinfos(Expr *clause, bool is_pushed_down,
+static RestrictInfo *make_restrictinfo_internal(Expr *clause,
+												Expr *orclause,
+												bool is_pushed_down,
+												bool valid_everywhere);
+static Expr *make_sub_restrictinfos(Expr *clause,
+									bool is_pushed_down,
 									bool valid_everywhere);
 static bool join_clause_is_redundant(Query *root,
 						 RestrictInfo *rinfo,
@@ -42,10 +47,89 @@ static bool join_clause_is_redundant(Query *root,
  */
 RestrictInfo *
 make_restrictinfo(Expr *clause, bool is_pushed_down, bool valid_everywhere)
+{
+	Expr	   *orclause;
+
+	/*
+	 * If it's an OR clause, build a modified copy with RestrictInfos
+	 * inserted above each subclause of the top-level AND/OR structure.
+	 */
+	if (or_clause((Node *) clause))
+	{
+		orclause = make_sub_restrictinfos(clause,
+										  is_pushed_down,
+										  valid_everywhere);
+	}
+	else
+	{
+		/* Shouldn't be an AND clause, else flatten_andors messed up */
+		Assert(!and_clause((Node *) clause));
+
+		orclause = NULL;
+	}
+
+	return make_restrictinfo_internal(clause, orclause,
+									  is_pushed_down, valid_everywhere);
+}
+
+/*
+ * make_restrictinfo_from_indexclauses
+ *
+ * Given an indexclauses structure, convert to ordinary expression format
+ * and build RestrictInfo node(s).
+ *
+ * The result is a List since we might need to return multiple RestrictInfos.
+ *
+ * This could be done as make_restrictinfo(make_expr_from_indexclauses()),
+ * but if we did it that way then we would strip the original RestrictInfo
+ * nodes from the index clauses and be forced to build new ones.  It's better
+ * to have a specialized routine that allows sharing of RestrictInfos.
+ */
+List *
+make_restrictinfo_from_indexclauses(List *indexclauses,
+									bool is_pushed_down,
+									bool valid_everywhere)
+{
+	List	   *withris = NIL;
+	List	   *withoutris = NIL;
+	List	   *orlist;
+
+	/* Empty list probably can't happen, but here's what to do */
+	if (indexclauses == NIL)
+		return NIL;
+	/* If single indexscan, just return the ANDed clauses */
+	if (lnext(indexclauses) == NIL)
+		return (List *) lfirst(indexclauses);
+	/* Else we need an OR RestrictInfo structure */
+	foreach(orlist, indexclauses)
+	{
+		List   *andlist = (List *) lfirst(orlist);
+
+		/* Create AND subclause with RestrictInfos */
+		withris = lappend(withris, make_ands_explicit(andlist));
+		/* And one without */
+		andlist = get_actual_clauses(andlist);
+		withoutris = lappend(withoutris, make_ands_explicit(andlist));
+	}
+	return makeList1(make_restrictinfo_internal(make_orclause(withoutris),
+												make_orclause(withris),
+												is_pushed_down,
+												valid_everywhere));
+}
+
+/*
+ * make_restrictinfo_internal
+ *
+ * Common code for the above two entry points.
+ */
+static RestrictInfo *
+make_restrictinfo_internal(Expr *clause, Expr *orclause,
+						   bool is_pushed_down, bool valid_everywhere)
 {
 	RestrictInfo *restrictinfo = makeNode(RestrictInfo);
 
 	restrictinfo->clause = clause;
+	restrictinfo->orclause = orclause;
 	restrictinfo->is_pushed_down = is_pushed_down;
 	restrictinfo->valid_everywhere = valid_everywhere;
 	restrictinfo->can_join = false;		/* may get set below */
@@ -83,24 +167,6 @@ make_restrictinfo(Expr *clause, bool is_pushed_down, bool valid_everywhere)
 		restrictinfo->clause_relids = pull_varnos((Node *) clause);
 	}
 
-	/*
-	 * If it's an OR clause, set up a modified copy with RestrictInfos
-	 * inserted above each subclause of the top-level AND/OR structure.
-	 */
-	if (or_clause((Node *) clause))
-	{
-		restrictinfo->orclause = make_sub_restrictinfos(clause,
-														is_pushed_down,
-														valid_everywhere);
-	}
-	else
-	{
-		/* Shouldn't be an AND clause, else flatten_andors messed up */
-		Assert(!and_clause((Node *) clause));
-
-		restrictinfo->orclause = NULL;
-	}
-
 	/*
 	 * Fill in all the cacheable fields with "not yet set" markers.
 	 * None of these will be computed until/unless needed.  Note in
@@ -161,9 +227,10 @@ make_sub_restrictinfos(Expr *clause, bool is_pushed_down,
 		return make_andclause(andlist);
 	}
 	else
-		return (Expr *) make_restrictinfo(clause,
-										  is_pushed_down,
-										  valid_everywhere);
+		return (Expr *) make_restrictinfo_internal(clause,
+												   NULL,
+												   is_pushed_down,
+												   valid_everywhere);
 }
 
 /*
@@ -193,9 +260,11 @@ get_actual_clauses(List *restrictinfo_list)
 
 	foreach(temp, restrictinfo_list)
 	{
-		RestrictInfo *clause = (RestrictInfo *) lfirst(temp);
+		RestrictInfo *rinfo = (RestrictInfo *) lfirst(temp);
+
+		Assert(IsA(rinfo, RestrictInfo));
 
-		result = lappend(result, clause->clause);
+		result = lappend(result, rinfo->clause);
 	}
 	return result;
 }

src/backend/utils/adt/selfuncs.c

@@ -15,7 +15,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.152 2003/12/29 22:22:45 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.153 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -94,6 +94,7 @@
 #include "optimizer/paths.h"
 #include "optimizer/plancat.h"
 #include "optimizer/prep.h"
+#include "optimizer/restrictinfo.h"
 #include "optimizer/tlist.h"
 #include "optimizer/var.h"
 #include "parser/parse_expr.h"
@@ -3896,13 +3897,13 @@ genericcostestimate(Query *root, RelOptInfo *rel,
 	double		numIndexTuples;
 	double		numIndexPages;
 	QualCost	index_qual_cost;
-	List	   *selectivityQuals = indexQuals;
+	List	   *selectivityQuals;
 
 	/*
 	 * If the index is partial, AND the index predicate with the
 	 * explicitly given indexquals to produce a more accurate idea of the
-	 * index selectivity.  This may produce redundant clauses.  We can get
-	 * rid of exact duplicates by using set_union().  We expect that most
+	 * index selectivity.  This may produce redundant clauses.  We get rid
+	 * of exact duplicates in the code below.  We expect that most
 	 * cases of partial redundancy (such as "x < 4" from the qual and
 	 * "x < 5" from the predicate) will be recognized and handled correctly
 	 * by clauselist_selectivity().  This assumption is somewhat fragile,
@@ -3913,10 +3914,25 @@ genericcostestimate(Query *root, RelOptInfo *rel,
 	 * necessarily a bad thing.  But it'd be nice to do better someday.
 	 *
 	 * Note that index->indpred and indexQuals are both in implicit-AND form,
-	 * so ANDing them together just takes merging the lists.
+	 * so ANDing them together just takes merging the lists.  However,
+	 * eliminating duplicates is a bit trickier because indexQuals contains
+	 * RestrictInfo nodes and the indpred does not.  It is okay to pass a
+	 * mixed list to clauselist_selectivity, but we have to work a bit to
+	 * generate a list without logical duplicates.  (We could just set_union
+	 * indpred and strippedQuals, but then we'd not get caching of per-qual
+	 * selectivity estimates.)
 	 */
 	if (index->indpred != NIL)
-		selectivityQuals = set_union(index->indpred, indexQuals);
+	{
+		List   *strippedQuals;
+		List   *predExtraQuals;
+
+		strippedQuals = get_actual_clauses(indexQuals);
+		predExtraQuals = set_difference(index->indpred, strippedQuals);
+		selectivityQuals = nconc(predExtraQuals, indexQuals);
+	}
+	else
+		selectivityQuals = indexQuals;
 
 	/* Estimate the fraction of main-table tuples that will be visited */
 	*indexSelectivity = clauselist_selectivity(root, selectivityQuals,

src/include/nodes/relation.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.92 2004/01/05 18:04:39 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.93 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -344,23 +344,24 @@ typedef struct Path
  *
  * 'indexinfo' is a list of IndexOptInfo nodes, one per scan to be performed.
  *
- * 'indexqual' is a list of index qualifications, also one per scan.
- * Each entry in 'indexqual' is a sublist of qualification expressions with
- * implicit AND semantics across the sublist items.  Only expressions that
- * are usable as indexquals (as determined by indxpath.c) may appear here.
- * NOTE that the semantics of the top-level list in 'indexqual' is OR
+ * 'indexclauses' is a list of index qualifications, also one per scan.
+ * Each entry in 'indexclauses' is a sublist of qualification clauses to be
+ * used for that scan, with implicit AND semantics across the sublist items.
+ * NOTE that the semantics of the top-level list in 'indexclauses' is OR
  * combination, while the sublists are implicitly AND combinations!
- * Also note that indexquals lists do not contain RestrictInfo nodes,
- * just bare clause expressions.
- *
- * 'indexjoinclauses' is NIL for an ordinary indexpath (one that does not
- * use any join clauses in the index conditions).  For an innerjoin indexpath,
- * it has the same structure as 'indexqual', but references the RestrictInfo
- * nodes from which the indexqual was built, rather than the bare clause
- * expressions.  (Note: there isn't necessarily a one-to-one correspondence
- * between RestrictInfos and expressions, because of expansion of special
- * indexable operators.)  We need this so that we can eliminate redundant
- * join clauses when plans are built.
+ *
+ * 'indexquals' has the same structure as 'indexclauses', but it contains
+ * the actual indexqual conditions that can be used with the index(es).
+ * In simple cases this is identical to 'indexclauses', but when special
+ * indexable operators appear in 'indexclauses', they are replaced by the
+ * derived indexscannable conditions in 'indexquals'.
+ *
+ * Both 'indexclauses' and 'indexquals' are lists of sublists of RestrictInfo
+ * nodes.  (Before 7.5, we kept bare operator expressions in these lists, but
+ * storing RestrictInfos is more efficient since selectivities can be cached.)
+ *
+ * 'isjoininner' is TRUE if the path is a nestloop inner scan (that is,
+ * some of the index conditions are join rather than restriction clauses).
  *
  * 'indexscandir' is one of:
  *		ForwardScanDirection: forward scan of an ordered index
@@ -381,8 +382,9 @@ typedef struct IndexPath
 {
 	Path		path;
 	List	   *indexinfo;
-	List	   *indexqual;
-	List	   *indexjoinclauses;
+	List	   *indexclauses;
+	List	   *indexquals;
+	bool		isjoininner;
 	ScanDirection indexscandir;
 	double		rows;			/* estimated number of result tuples */
 } IndexPath;

src/include/optimizer/paths.h

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.72 2004/01/05 05:07:36 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/paths.h,v 1.73 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -44,6 +44,8 @@ extern List *group_clauses_by_indexkey_for_or(RelOptInfo *rel,
 extern List *expand_indexqual_conditions(IndexOptInfo *index,
 							List *clausegroups);
 extern void check_partial_indexes(Query *root, RelOptInfo *rel);
+extern List *flatten_clausegroups_list(List *clausegroups);
+extern Expr *make_expr_from_indexclauses(List *indexclauses);
 
 /*
  * orindxpath.c

src/include/optimizer/restrictinfo.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/optimizer/restrictinfo.h,v 1.22 2004/01/05 05:07:36 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/optimizer/restrictinfo.h,v 1.23 2004/01/05 23:39:54 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,6 +18,9 @@
 
 extern RestrictInfo *make_restrictinfo(Expr *clause, bool is_pushed_down,
 									   bool valid_everywhere);
+extern List *make_restrictinfo_from_indexclauses(List *indexclauses,
+												 bool is_pushed_down,
+												 bool valid_everywhere);
 extern bool restriction_is_or_clause(RestrictInfo *restrictinfo);
 extern List *get_actual_clauses(List *restrictinfo_list);
 extern void get_actual_join_clauses(List *restrictinfo_list,