Tid access method feature from Hiroshi Inoue, Inoue@tpf.co.jp

src/backend/optimizer/path/Makefile

@@ -4,7 +4,7 @@
 #    Makefile for optimizer/path
 #
 # IDENTIFICATION
-#    $Header: /cvsroot/pgsql/src/backend/optimizer/path/Makefile,v 1.9 1999/08/16 02:17:50 tgl Exp $
+#    $Header: /cvsroot/pgsql/src/backend/optimizer/path/Makefile,v 1.10 1999/11/23 20:06:54 momjian Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -14,7 +14,8 @@ include ../../../Makefile.global
 CFLAGS += -I../..
 
 OBJS = allpaths.o clausesel.o costsize.o indxpath.o \
-       joinpath.o joinrels.o orindxpath.o pathkeys.o prune.o
+       joinpath.o joinrels.o orindxpath.o pathkeys.o prune.o \
+	tidpath.o
 
 all: SUBSYS.o
 

src/backend/optimizer/path/allpaths.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.53 1999/08/16 02:17:50 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.54 1999/11/23 20:06:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -108,9 +108,14 @@ set_base_rel_pathlist(Query *root, List *rels)
 		List	   *sequential_scan_list;
 		List	   *rel_index_scan_list;
 		List	   *or_index_scan_list;
+		List	   *tidscan_pathlist;
 
 		sequential_scan_list = lcons(create_seqscan_path(rel), NIL);
-
+		/* Tid Scan Pathlist add */
+		tidscan_pathlist = create_tidscan_paths(root, rel);
+		if (tidscan_pathlist)
+			sequential_scan_list = nconc(sequential_scan_list,
+				tidscan_pathlist);
 		rel_index_scan_list = create_index_paths(root,
 												 rel,
 												 indices,

src/backend/optimizer/path/costsize.c

@@ -18,7 +18,7 @@
  * Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.45 1999/08/22 20:14:41 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/costsize.c,v 1.46 1999/11/23 20:06:54 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -59,6 +59,7 @@ bool		_enable_sort_ = true;
 bool		_enable_nestloop_ = true;
 bool		_enable_mergejoin_ = true;
 bool		_enable_hashjoin_ = true;
+bool		_enable_tidscan_ = true;
 
 Cost		 _cpu_page_weight_ = _CPU_PAGE_WEIGHT_;
 Cost		_cpu_index_page_weight_ = _CPU_INDEX_PAGE_WEIGHT_;
@@ -174,6 +175,29 @@ cost_index(Oid indexid,
 	return temp;
 }
 
+/*
+ * cost_tidscan
+ *	  Determines and returns the cost of scanning a relation using tid-s.
+ *
+ *		disk = number of tids
+ *		cpu = *CPU-PAGE-WEIGHT* * number_of_tids
+ *
+ * Returns a flonum.
+ *
+ */
+Cost
+cost_tidscan(List *tideval)
+{
+	Cost	temp = 0;
+
+	if (!_enable_tidscan_)
+		temp += _disable_cost_;
+
+	temp += (1.0 + _cpu_page_weight_) * length(tideval);
+
+	return temp;
+}
+ 
 /*
  * cost_sort
  *	  Determines and returns the cost of sorting a relation by considering

src/backend/optimizer/path/tidpath.c

@@ -0,0 +1,296 @@
+/*-------------------------------------------------------------------------
+ *
+ * tidpath.c
+ *	  Routines to determine which tids are usable for scanning a
+ *	  given relation, and create TidPaths accordingly.
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/path/tidpath.c,v 1.1 1999/11/23 20:06:55 momjian Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include <math.h>
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "catalog/catname.h"
+#include "catalog/pg_amop.h"
+#include "catalog/pg_operator.h"
+#include "executor/executor.h"
+#include "nodes/makefuncs.h"
+#include "nodes/nodeFuncs.h"
+#include "optimizer/clauses.h"
+#include "optimizer/cost.h"
+#include "optimizer/pathnode.h"
+#include "optimizer/paths.h"
+#include "optimizer/plancat.h"
+#include "optimizer/restrictinfo.h"
+#include "parser/parse_coerce.h"
+#include "parser/parse_expr.h"
+#include "parser/parse_oper.h"
+#include "parser/parsetree.h"
+#include "utils/lsyscache.h"
+
+static List	*create_tidscan_joinpaths(RelOptInfo *);
+static List	*TidqualFromRestrictinfo(List *relids, List * restrictinfo);
+static bool	isEvaluable(int varno, Node *node);
+static Node	*TidequalClause(int varno, Expr *node);
+static List	*TidqualFromExpr(int varno, Expr *expr);
+
+static
+bool isEvaluable(int varno, Node *node)
+{
+	List	*lst;
+	Expr	*expr;
+
+	if (IsA(node, Const))		return true;
+	if (IsA(node, Param))		return true;
+	if (IsA(node, Var))
+	{
+		Var	*var = (Var *)node;
+
+		if (var->varno == varno)
+			return false;
+		return true;
+	}
+	if (!is_funcclause(node))	return false;
+	expr = (Expr *)node;
+	foreach (lst, expr->args)
+	{
+		if (!isEvaluable(varno, lfirst(lst)))
+			return false;
+	}
+
+	return true;
+}
+
+/*
+ *	The 2nd parameter should be an opclause
+ *	Extract the right node if the opclause is CTID= ....
+ *	  or    the left  node if the opclause is ....=CTID
+ */
+static
+Node *TidequalClause(int varno, Expr *node)
+{
+	Node	*rnode = 0, *arg1, *arg2, *arg;
+	Oper	*oper;
+	Var	*var;
+	Const	*aconst;
+	Param	*param;
+	Expr	*expr;
+
+	if (!node->oper)		return rnode;
+	if (!node->args)		return rnode;
+	if (length(node->args) != 2)	return rnode;
+        oper = (Oper *) node->oper;
+	if (oper->opno != TIDEqualOperator)
+		return rnode;
+	arg1 = lfirst(node->args);
+	arg2 = lsecond(node->args);
+
+	arg = (Node *)0;
+	if (IsA(arg1, Var))
+	{
+		var = (Var *) arg1;
+		if (var->varno == varno &&
+		    var->varattno == SelfItemPointerAttributeNumber &&
+		    var->vartype == TIDOID)
+			arg = arg2;
+		else if (var->varnoold == varno &&
+		    	var->varoattno == SelfItemPointerAttributeNumber &&
+		    	var->vartype == TIDOID)
+			arg = arg2;
+	}
+	if ((!arg) && IsA(arg2, Var))
+	{
+		var = (Var *) arg2;
+		if (var->varno == varno &&
+		    var->varattno == SelfItemPointerAttributeNumber &&
+		    var->vartype == TIDOID)
+			arg = arg1;
+	}
+	if (!arg)
+		return rnode;
+	switch (nodeTag(arg))
+	{
+	 	case T_Const:
+			aconst = (Const *) arg;
+			if (aconst->consttype != TIDOID)
+				return rnode;
+			if (aconst->constbyval)
+				return rnode;
+			rnode = arg;
+			break;
+	 	case T_Param:
+			param = (Param *) arg;
+			if (param->paramtype != TIDOID)
+				return rnode;
+			rnode = arg;
+			break;
+	 	case T_Var:
+			var = (Var *) arg;
+			if (var->varno == varno ||
+			    var->vartype != TIDOID)
+				return rnode;
+			rnode = arg;
+			break;
+	 	case T_Expr:
+			expr = (Expr *) arg;
+			if (expr->typeOid != TIDOID)	return rnode;
+			if (expr->opType != FUNC_EXPR)	return rnode;
+			if (isEvaluable(varno, (Node *)expr))
+				rnode = arg;
+			break;
+	 	default:
+			break;
+	}
+	return rnode;
+}
+
+/*
+ *	Extract the list of CTID values from a specified expr node.
+ *	When the expr node is an or_clause,we try to extract CTID
+ *	values from all member nodes. However we would discard them
+ *	all if we couldn't extract CTID values from a member node.
+ *	When the expr node is an and_clause,we return the list of
+ *	CTID values if we could extract the CTID values from a member
+ *	node.
+ */ 
+static
+List *TidqualFromExpr(int varno, Expr *expr)
+{
+	List	*rlst = NIL, *lst, *frtn;
+	Node	*node = (Node *) expr, *rnode;
+
+	if (is_opclause(node))
+	{
+		rnode = TidequalClause(varno, expr);
+		if (rnode)
+		{
+			rlst = lcons(rnode, rlst);
+		} 
+	}
+	else if (and_clause(node))
+	{
+		foreach (lst, expr->args)
+		{
+			node = lfirst(lst);
+			if (!IsA(node, Expr))	
+				continue;
+			rlst = TidqualFromExpr(varno, (Expr *)node);
+			if (rlst)
+				break;
+		}
+	}
+	else if (or_clause(node))
+	{
+		foreach (lst, expr->args)
+		{
+			node = lfirst(lst);
+			if (IsA(node, Expr) &&
+			    (frtn = TidqualFromExpr(varno, (Expr *)node)) )
+			{
+				rlst = nconc(rlst, frtn);
+			}
+			else
+			{
+				if (rlst)
+					freeList(rlst);
+				rlst = NIL;
+				break;
+			}
+		}
+	}
+	return rlst;
+} 
+
+static
+List *TidqualFromRestrictinfo(List *relids, List * restrictinfo)
+{
+	List	*lst, *rlst = NIL;
+	int	varno;
+	Node	*node;
+	Expr	*expr;
+
+	if (length(relids)>1)	return NIL;
+	varno = (int)lfirst(relids);
+	foreach (lst, restrictinfo)
+	{
+		node = lfirst(lst);
+		if (!IsA(node, RestrictInfo))	continue;
+		expr = ((RestrictInfo *)node)->clause;
+		rlst = TidqualFromExpr(varno, expr);
+		if (rlst)
+		{
+			break;
+		}
+	}
+	return rlst;
+}
+
+/*
+ * create_tidscan_joinpaths
+ *	  Creates a path corresponding to a tid_direct scan, returning the
+ *	  pathnode.
+ *
+ */
+List *
+create_tidscan_joinpaths(RelOptInfo *rel)
+{
+	List		*rlst = NIL, *lst;
+	TidPath		*pathnode = (TidPath *)0;
+	List		*restinfo, *tideval;
+
+	foreach (lst, rel->joininfo)
+	{
+		JoinInfo *joininfo = (JoinInfo *)lfirst(lst);
+		restinfo = joininfo->jinfo_restrictinfo;
+		tideval = TidqualFromRestrictinfo(rel->relids, restinfo);
+		if (tideval && length(tideval) == 1)
+		{
+			pathnode = makeNode(TidPath);
+
+			pathnode->path.pathtype = T_TidScan;
+			pathnode->path.parent = rel;
+			pathnode->path.path_cost = 0.0;
+			pathnode->path.pathkeys = NIL;
+
+			pathnode->path.path_cost = cost_tidscan(tideval);
+			pathnode->tideval = tideval;
+			/*
+			pathnode->tideval = copyObject(tideval);
+			freeList(tideval);
+			*/
+			pathnode->unjoined_relids = joininfo->unjoined_relids;
+			rlst = lappend(rlst, pathnode);
+		}
+	}
+	rel->innerjoin = nconc(rel->innerjoin, rlst);
+	return rlst;
+}
+
+/*
+ * create_tidscan_paths
+ *	  Creates a path corresponding to a tid direct scan, returning the
+ *	  pathnode List.
+ *
+ */
+List *
+create_tidscan_paths(Query *root, RelOptInfo *rel)
+{
+	List	*rlst = NIL;
+	TidPath	*pathnode = (TidPath *)0;
+	List	*tideval = TidqualFromRestrictinfo(rel->relids, rel->restrictinfo);
+	
+	if (tideval)
+		pathnode = create_tidscan_path(rel, tideval);
+	if (pathnode)
+		rlst = lcons(pathnode, rlst);
+	create_tidscan_joinpaths(rel);
+
+	return rlst;
+}