diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 7b003dc095c8446fb4ef0deea1a527c2d36020cc..1237dc7fe642c8797651cce727d689dbbf720845 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.362 2007/01/20 20:45:38 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/nodes/copyfuncs.c,v 1.363 2007/01/22 20:00:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1326,6 +1326,10 @@ _copyRestrictInfo(RestrictInfo *from)
/* EquivalenceClasses are never copied, so shallow-copy the pointers */
COPY_SCALAR_FIELD(left_ec);
COPY_SCALAR_FIELD(right_ec);
+ COPY_SCALAR_FIELD(left_em);
+ COPY_SCALAR_FIELD(right_em);
+ /* MergeScanSelCache isn't a Node, so hard to copy; just reset cache */
+ newnode->scansel_cache = NIL;
COPY_SCALAR_FIELD(outer_is_left);
COPY_SCALAR_FIELD(hashjoinoperator);
COPY_SCALAR_FIELD(left_bucketsize);
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index f0b72ea0f643987a46ad91a2d05bb973254c67d6..b79b7d1a2d8f8a12017cfc17c428f50fe6d6c212 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.294 2007/01/20 20:45:38 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/nodes/outfuncs.c,v 1.295 2007/01/22 20:00:39 tgl Exp $
*
* NOTES
* Every node type that can appear in stored rules' parsetrees *must*
@@ -1304,6 +1304,7 @@ _outEquivalenceClass(StringInfo str, EquivalenceClass *node)
WRITE_NODE_FIELD(ec_opfamilies);
WRITE_NODE_FIELD(ec_members);
WRITE_NODE_FIELD(ec_sources);
+ WRITE_NODE_FIELD(ec_derives);
WRITE_BITMAPSET_FIELD(ec_relids);
WRITE_BOOL_FIELD(ec_has_const);
WRITE_BOOL_FIELD(ec_has_volatile);
@@ -1354,6 +1355,8 @@ _outRestrictInfo(StringInfo str, RestrictInfo *node)
WRITE_NODE_FIELD(mergeopfamilies);
WRITE_NODE_FIELD(left_ec);
WRITE_NODE_FIELD(right_ec);
+ WRITE_NODE_FIELD(left_em);
+ WRITE_NODE_FIELD(right_em);
WRITE_BOOL_FIELD(outer_is_left);
WRITE_OID_FIELD(hashjoinoperator);
}
diff --git a/src/backend/optimizer/path/costsize.c b/src/backend/optimizer/path/costsize.c
index 2d241e774d0174136d203c022141a92bd5f8f9f1..422ef9232226ad82dd22d73f2d712b5eb80a0c90 100644
--- a/src/backend/optimizer/path/costsize.c
+++ b/src/backend/optimizer/path/costsize.c
@@ -54,7 +54,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.176 2007/01/22 01:35:20 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/path/costsize.c,v 1.177 2007/01/22 20:00:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -108,6 +108,9 @@ bool enable_mergejoin = true;
bool enable_hashjoin = true;
+static MergeScanSelCache *cached_scansel(PlannerInfo *root,
+ RestrictInfo *rinfo,
+ PathKey *pathkey);
static bool cost_qual_eval_walker(Node *node, QualCost *total);
static Selectivity approx_selectivity(PlannerInfo *root, List *quals,
JoinType jointype);
@@ -1349,9 +1352,9 @@ cost_mergejoin(MergePath *path, PlannerInfo *root)
* (unless it's an outer join, in which case the outer side has to be
* scanned all the way anyway). Estimate fraction of the left and right
* inputs that will actually need to be scanned. We use only the first
- * (most significant) merge clause for this purpose.
- *
- * XXX mergejoinscansel is a bit expensive, can we cache its results?
+ * (most significant) merge clause for this purpose. Since
+ * mergejoinscansel() is a fairly expensive computation, we cache the
+ * results in the merge clause RestrictInfo.
*/
if (mergeclauses && path->jpath.jointype != JOIN_FULL)
{
@@ -1360,8 +1363,7 @@ cost_mergejoin(MergePath *path, PlannerInfo *root)
List *ipathkeys;
PathKey *opathkey;
PathKey *ipathkey;
- Selectivity leftscansel,
- rightscansel;
+ MergeScanSelCache *cache;
/* Get the input pathkeys to determine the sort-order details */
opathkeys = outersortkeys ? outersortkeys : outer_path->pathkeys;
@@ -1376,22 +1378,21 @@ cost_mergejoin(MergePath *path, PlannerInfo *root)
opathkey->pk_nulls_first != ipathkey->pk_nulls_first)
elog(ERROR, "left and right pathkeys do not match in mergejoin");
- mergejoinscansel(root, (Node *) firstclause->clause,
- opathkey->pk_opfamily, opathkey->pk_strategy,
- &leftscansel, &rightscansel);
+ /* Get the selectivity with caching */
+ cache = cached_scansel(root, firstclause, opathkey);
if (bms_is_subset(firstclause->left_relids,
outer_path->parent->relids))
{
/* left side of clause is outer */
- outerscansel = leftscansel;
- innerscansel = rightscansel;
+ outerscansel = cache->leftscansel;
+ innerscansel = cache->rightscansel;
}
else
{
/* left side of clause is inner */
- outerscansel = rightscansel;
- innerscansel = leftscansel;
+ outerscansel = cache->rightscansel;
+ innerscansel = cache->leftscansel;
}
if (path->jpath.jointype == JOIN_LEFT)
outerscansel = 1.0;
@@ -1493,6 +1494,54 @@ cost_mergejoin(MergePath *path, PlannerInfo *root)
path->jpath.path.total_cost = startup_cost + run_cost;
}
+/*
+ * run mergejoinscansel() with caching
+ */
+static MergeScanSelCache *
+cached_scansel(PlannerInfo *root, RestrictInfo *rinfo, PathKey *pathkey)
+{
+ MergeScanSelCache *cache;
+ ListCell *lc;
+ Selectivity leftscansel,
+ rightscansel;
+ MemoryContext oldcontext;
+
+ /* Do we have this result already? */
+ foreach(lc, rinfo->scansel_cache)
+ {
+ cache = (MergeScanSelCache *) lfirst(lc);
+ if (cache->opfamily == pathkey->pk_opfamily &&
+ cache->strategy == pathkey->pk_strategy &&
+ cache->nulls_first == pathkey->pk_nulls_first)
+ return cache;
+ }
+
+ /* Nope, do the computation */
+ mergejoinscansel(root,
+ (Node *) rinfo->clause,
+ pathkey->pk_opfamily,
+ pathkey->pk_strategy,
+ pathkey->pk_nulls_first,
+ &leftscansel,
+ &rightscansel);
+
+ /* Cache the result in suitably long-lived workspace */
+ oldcontext = MemoryContextSwitchTo(root->planner_cxt);
+
+ cache = (MergeScanSelCache *) palloc(sizeof(MergeScanSelCache));
+ cache->opfamily = pathkey->pk_opfamily;
+ cache->strategy = pathkey->pk_strategy;
+ cache->nulls_first = pathkey->pk_nulls_first;
+ cache->leftscansel = leftscansel;
+ cache->rightscansel = rightscansel;
+
+ rinfo->scansel_cache = lappend(rinfo->scansel_cache, cache);
+
+ MemoryContextSwitchTo(oldcontext);
+
+ return cache;
+}
+
/*
* cost_hashjoin
* Determines and returns the cost of joining two relations using the
diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c
index 063e8d5d014b9037c713253f4977693c64a6e24b..b6503ef193be72ff32c3332e026a1163a9c49897 100644
--- a/src/backend/optimizer/path/equivclass.c
+++ b/src/backend/optimizer/path/equivclass.c
@@ -10,7 +10,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/path/equivclass.c,v 1.1 2007/01/20 20:45:39 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/path/equivclass.c,v 1.2 2007/01/22 20:00:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -26,8 +26,9 @@
#include "utils/lsyscache.h"
-static void add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
- bool is_child, Oid datatype);
+static EquivalenceMember *add_eq_member(EquivalenceClass *ec,
+ Expr *expr, Relids relids,
+ bool is_child, Oid datatype);
static void generate_base_implied_equalities_const(PlannerInfo *root,
EquivalenceClass *ec);
static void generate_base_implied_equalities_no_const(PlannerInfo *root,
@@ -46,6 +47,11 @@ static List *generate_join_implied_equalities_broken(PlannerInfo *root,
RelOptInfo *inner_rel);
static Oid select_equality_operator(EquivalenceClass *ec,
Oid lefttype, Oid righttype);
+static RestrictInfo *create_join_clause(PlannerInfo *root,
+ EquivalenceClass *ec, Oid opno,
+ EquivalenceMember *leftem,
+ EquivalenceMember *rightem,
+ EquivalenceClass *parent_ec);
static void reconsider_outer_join_clause(PlannerInfo *root,
RestrictInfo *rinfo,
bool outer_on_left);
@@ -95,6 +101,8 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
List *opfamilies;
EquivalenceClass *ec1,
*ec2;
+ EquivalenceMember *em1,
+ *em2;
ListCell *lc1;
/* Extract info from given clause */
@@ -152,6 +160,7 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
* there is no shortcut here for item1 and item2 equal.)
*/
ec1 = ec2 = NULL;
+ em1 = em2 = NULL;
foreach(lc1, root->eq_classes)
{
EquivalenceClass *cur_ec = (EquivalenceClass *) lfirst(lc1);
@@ -188,6 +197,7 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
equal(item1, cur_em->em_expr))
{
ec1 = cur_ec;
+ em1 = cur_em;
if (ec2)
break;
}
@@ -197,6 +207,7 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
equal(item2, cur_em->em_expr))
{
ec2 = cur_ec;
+ em2 = cur_em;
if (ec1)
break;
}
@@ -215,6 +226,10 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
{
ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
ec1->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as usable with this pair of EMs */
+ /* NB: can't set left_ec/right_ec until merging is finished */
+ restrictinfo->left_em = em1;
+ restrictinfo->right_em = em2;
return true;
}
@@ -227,6 +242,7 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
*/
ec1->ec_members = list_concat(ec1->ec_members, ec2->ec_members);
ec1->ec_sources = list_concat(ec1->ec_sources, ec2->ec_sources);
+ ec1->ec_derives = list_concat(ec1->ec_derives, ec2->ec_derives);
ec1->ec_relids = bms_join(ec1->ec_relids, ec2->ec_relids);
ec1->ec_has_const |= ec2->ec_has_const;
/* can't need to set has_volatile */
@@ -236,23 +252,33 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
/* just to avoid debugging confusion w/ dangling pointers: */
ec2->ec_members = NIL;
ec2->ec_sources = NIL;
+ ec2->ec_derives = NIL;
ec2->ec_relids = NULL;
ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
ec1->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as usable with this pair of EMs */
+ restrictinfo->left_em = em1;
+ restrictinfo->right_em = em2;
}
else if (ec1)
{
/* Case 3: add item2 to ec1 */
- add_eq_member(ec1, item2, item2_relids, false, item2_type);
+ em2 = add_eq_member(ec1, item2, item2_relids, false, item2_type);
ec1->ec_sources = lappend(ec1->ec_sources, restrictinfo);
ec1->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as usable with this pair of EMs */
+ restrictinfo->left_em = em1;
+ restrictinfo->right_em = em2;
}
else if (ec2)
{
/* Case 3: add item1 to ec2 */
- add_eq_member(ec2, item1, item1_relids, false, item1_type);
+ em1 = add_eq_member(ec2, item1, item1_relids, false, item1_type);
ec2->ec_sources = lappend(ec2->ec_sources, restrictinfo);
ec2->ec_below_outer_join |= below_outer_join;
+ /* mark the RI as usable with this pair of EMs */
+ restrictinfo->left_em = em1;
+ restrictinfo->right_em = em2;
}
else
{
@@ -262,16 +288,21 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
ec->ec_opfamilies = opfamilies;
ec->ec_members = NIL;
ec->ec_sources = list_make1(restrictinfo);
+ ec->ec_derives = NIL;
ec->ec_relids = NULL;
ec->ec_has_const = false;
ec->ec_has_volatile = false;
ec->ec_below_outer_join = below_outer_join;
ec->ec_broken = false;
ec->ec_merged = NULL;
- add_eq_member(ec, item1, item1_relids, false, item1_type);
- add_eq_member(ec, item2, item2_relids, false, item2_type);
+ em1 = add_eq_member(ec, item1, item1_relids, false, item1_type);
+ em2 = add_eq_member(ec, item2, item2_relids, false, item2_type);
root->eq_classes = lappend(root->eq_classes, ec);
+
+ /* mark the RI as usable with this pair of EMs */
+ restrictinfo->left_em = em1;
+ restrictinfo->right_em = em2;
}
return true;
@@ -280,7 +311,7 @@ process_equivalence(PlannerInfo *root, RestrictInfo *restrictinfo,
/*
* add_eq_member - build a new EquivalenceMember and add it to an EC
*/
-static void
+static EquivalenceMember *
add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
bool is_child, Oid datatype)
{
@@ -312,6 +343,8 @@ add_eq_member(EquivalenceClass *ec, Expr *expr, Relids relids,
ec->ec_relids = bms_add_members(ec->ec_relids, relids);
}
ec->ec_members = lappend(ec->ec_members, em);
+
+ return em;
}
@@ -337,6 +370,7 @@ get_eclass_for_sort_expr(PlannerInfo *root,
List *opfamilies)
{
EquivalenceClass *newec;
+ EquivalenceMember *newem;
ListCell *lc1;
MemoryContext oldcontext;
@@ -383,14 +417,15 @@ get_eclass_for_sort_expr(PlannerInfo *root,
newec->ec_opfamilies = list_copy(opfamilies);
newec->ec_members = NIL;
newec->ec_sources = NIL;
+ newec->ec_derives = NIL;
newec->ec_relids = NULL;
newec->ec_has_const = false;
newec->ec_has_volatile = contain_volatile_functions((Node *) expr);
newec->ec_below_outer_join = false;
newec->ec_broken = false;
newec->ec_merged = NULL;
- add_eq_member(newec, expr, pull_varnos((Node *) expr),
- false, expr_datatype);
+ newem = add_eq_member(newec, expr, pull_varnos((Node *) expr),
+ false, expr_datatype);
/*
* add_eq_member doesn't check for volatile functions or aggregates,
@@ -402,7 +437,7 @@ get_eclass_for_sort_expr(PlannerInfo *root,
if (newec->ec_has_volatile || contain_agg_clause((Node *) expr))
{
newec->ec_has_const = false;
- ((EquivalenceMember *) linitial(newec->ec_members))->em_is_const = false;
+ newem->em_is_const = false;
}
}
@@ -455,6 +490,12 @@ get_eclass_for_sort_expr(PlannerInfo *root,
* process_implied_equality (in plan/initsplan.c) to be inserted into the
* restrictinfo datastructures. Note that this must be called after initial
* scanning of the quals and before Path construction begins.
+ *
+ * We make no attempt to avoid generating duplicate RestrictInfos here: we
+ * don't search ec_sources for matches, nor put the created RestrictInfos
+ * into ec_derives. Doing so would require some slightly ugly changes in
+ * initsplan.c's API, and there's no real advantage, because the clauses
+ * generated here can't duplicate anything we will generate for joins anyway.
*/
void
generate_base_implied_equalities(PlannerInfo *root)
@@ -664,6 +705,13 @@ generate_base_implied_equalities_broken(PlannerInfo *root,
* for use in a nestloop-with-inner-indexscan join, however. indxpath.c makes
* its own selections of clauses to use, and if the ones we pick here are
* redundant with those, the extras will be eliminated in createplan.c.
+ *
+ * Because the same join clauses are likely to be needed multiple times as
+ * we consider different join paths, we avoid generating multiple copies:
+ * whenever we select a particular pair of EquivalenceMembers to join,
+ * we check to see if the pair matches any original clause (in ec_sources)
+ * or previously-built clause (in ec_derives). This saves memory and allows
+ * re-use of information cached in RestrictInfos.
*/
List *
generate_join_implied_equalities(PlannerInfo *root,
@@ -818,15 +866,13 @@ generate_join_implied_equalities_normal(PlannerInfo *root,
return NIL;
}
- rinfo = build_implied_join_equality(best_eq_op,
- best_outer_em->em_expr,
- best_inner_em->em_expr,
- ec->ec_relids);
- /* mark restrictinfo as redundant with other joinclauses */
- rinfo->parent_ec = ec;
- /* we can set these too, rather than letting them be looked up later */
- rinfo->left_ec = ec;
- rinfo->right_ec = ec;
+ /*
+ * Create clause, setting parent_ec to mark it as redundant with other
+ * joinclauses
+ */
+ rinfo = create_join_clause(root, ec, best_eq_op,
+ best_outer_em, best_inner_em,
+ ec);
result = lappend(result, rinfo);
}
@@ -867,16 +913,10 @@ generate_join_implied_equalities_normal(PlannerInfo *root,
ec->ec_broken = true;
return NIL;
}
- rinfo = build_implied_join_equality(eq_op,
- prev_em->em_expr,
- cur_em->em_expr,
- ec->ec_relids);
-
/* do NOT set parent_ec, this qual is not redundant! */
-
- /* we can set these, though */
- rinfo->left_ec = ec;
- rinfo->right_ec = ec;
+ rinfo = create_join_clause(root, ec, eq_op,
+ prev_em, cur_em,
+ NULL);
result = lappend(result, rinfo);
}
@@ -941,6 +981,86 @@ select_equality_operator(EquivalenceClass *ec, Oid lefttype, Oid righttype)
}
+/*
+ * create_join_clause
+ * Find or make a RestrictInfo comparing the two given EC members
+ * with the given operator.
+ *
+ * parent_ec is either equal to ec (if the clause is a potentially-redundant
+ * join clause) or NULL (if not). We have to treat this as part of the
+ * match requirements --- it's possible that a clause comparing the same two
+ * EMs is a join clause in one join path and a restriction clause in another.
+ */
+static RestrictInfo *
+create_join_clause(PlannerInfo *root,
+ EquivalenceClass *ec, Oid opno,
+ EquivalenceMember *leftem,
+ EquivalenceMember *rightem,
+ EquivalenceClass *parent_ec)
+{
+ RestrictInfo *rinfo;
+ ListCell *lc;
+ MemoryContext oldcontext;
+
+ /*
+ * Search to see if we already built a RestrictInfo for this pair of
+ * EquivalenceMembers. We can use either original source clauses or
+ * previously-derived clauses. The check on opno is probably redundant,
+ * but be safe ...
+ */
+ foreach(lc, ec->ec_sources)
+ {
+ rinfo = (RestrictInfo *) lfirst(lc);
+ if (rinfo->left_em == leftem &&
+ rinfo->right_em == rightem &&
+ rinfo->parent_ec == parent_ec &&
+ opno == ((OpExpr *) rinfo->clause)->opno)
+ return rinfo;
+ }
+
+ foreach(lc, ec->ec_derives)
+ {
+ rinfo = (RestrictInfo *) lfirst(lc);
+ if (rinfo->left_em == leftem &&
+ rinfo->right_em == rightem &&
+ rinfo->parent_ec == parent_ec &&
+ opno == ((OpExpr *) rinfo->clause)->opno)
+ return rinfo;
+ }
+
+ /*
+ * Not there, so build it, in planner context so we can re-use it.
+ * (Not important in normal planning, but definitely so in GEQO.)
+ */
+ oldcontext = MemoryContextSwitchTo(root->planner_cxt);
+
+ rinfo = build_implied_join_equality(opno,
+ leftem->em_expr,
+ rightem->em_expr,
+ ec->ec_relids);
+
+ /* Mark the clause as redundant, or not */
+ rinfo->parent_ec = parent_ec;
+
+ /*
+ * We can set these now, rather than letting them be looked up later,
+ * since this is only used after EC merging is complete.
+ */
+ rinfo->left_ec = ec;
+ rinfo->right_ec = ec;
+
+ /* Mark it as usable with these EMs */
+ rinfo->left_em = leftem;
+ rinfo->right_em = rightem;
+ /* and save it for possible re-use */
+ ec->ec_derives = lappend(ec->ec_derives, rinfo);
+
+ MemoryContextSwitchTo(oldcontext);
+
+ return rinfo;
+}
+
+
/*
* reconsider_outer_join_clauses
* Re-examine any outer-join clauses that were set aside by
@@ -1364,8 +1484,8 @@ add_child_rel_equivalences(PlannerInfo *root,
child_expr = (Expr *)
adjust_appendrel_attrs((Node *) cur_em->em_expr,
appinfo);
- add_eq_member(cur_ec, child_expr, child_rel->relids,
- true, cur_em->em_datatype);
+ (void) add_eq_member(cur_ec, child_expr, child_rel->relids,
+ true, cur_em->em_datatype);
}
}
}
@@ -1451,15 +1571,10 @@ find_eclass_clauses_for_index_join(PlannerInfo *root, RelOptInfo *rel,
/* Found a suitable joinclause */
RestrictInfo *rinfo;
- rinfo = build_implied_join_equality(best_eq_op,
- cur_em->em_expr,
- best_outer_em->em_expr,
- cur_ec->ec_relids);
- /* mark restrictinfo as redundant with other joinclauses */
- rinfo->parent_ec = cur_ec;
- /* we can set these too */
- rinfo->left_ec = cur_ec;
- rinfo->right_ec = cur_ec;
+ /* set parent_ec to mark as redundant with other joinclauses */
+ rinfo = create_join_clause(root, cur_ec, best_eq_op,
+ cur_em, best_outer_em,
+ cur_ec);
result = lappend(result, rinfo);
/*
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c
index ec93b0dad07ba5b9f87429f1d4ea2431b8b86917..5ee03b75cffd7e87e9d1322eda94390cb5f8f710 100644
--- a/src/backend/optimizer/prep/prepunion.c
+++ b/src/backend/optimizer/prep/prepunion.c
@@ -22,7 +22,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.136 2007/01/20 20:45:39 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/prep/prepunion.c,v 1.137 2007/01/22 20:00:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1197,6 +1197,9 @@ adjust_appendrel_attrs_mutator(Node *node, AppendRelInfo *context)
newinfo->this_selec = -1;
newinfo->left_ec = NULL;
newinfo->right_ec = NULL;
+ newinfo->left_em = NULL;
+ newinfo->right_em = NULL;
+ newinfo->scansel_cache = NIL;
newinfo->left_bucketsize = -1;
newinfo->right_bucketsize = -1;
diff --git a/src/backend/optimizer/util/restrictinfo.c b/src/backend/optimizer/util/restrictinfo.c
index ea8bb5c970b3b376b0c7c4924158398f092751f7..8251e75d650a66bf8cefe98394bc6894788b659b 100644
--- a/src/backend/optimizer/util/restrictinfo.c
+++ b/src/backend/optimizer/util/restrictinfo.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.52 2007/01/20 20:45:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.53 2007/01/22 20:00:39 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -344,6 +344,9 @@ make_restrictinfo_internal(Expr *clause,
restrictinfo->left_ec = NULL;
restrictinfo->right_ec = NULL;
+ restrictinfo->left_em = NULL;
+ restrictinfo->right_em = NULL;
+ restrictinfo->scansel_cache = NIL;
restrictinfo->outer_is_left = false;
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 493df17b6c22ed9a8b811655430aa9a54740b09f..85e66a3b1c47beaa1fe79fb027b4d1ea0b9c004a 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.220 2007/01/20 20:45:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/utils/adt/selfuncs.c,v 1.221 2007/01/22 20:00:40 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -2112,8 +2112,8 @@ icnlikejoinsel(PG_FUNCTION_ARGS)
* we can estimate how much of the input will actually be read. This
* can have a considerable impact on the cost when using indexscans.
*
- * clause should be a clause already known to be mergejoinable. opfamily and
- * strategy specify the sort ordering being used.
+ * clause should be a clause already known to be mergejoinable. opfamily,
+ * strategy, and nulls_first specify the sort ordering being used.
*
* *leftscan is set to the fraction of the left-hand variable expected
* to be scanned (0 to 1), and similarly *rightscan for the right-hand
@@ -2121,7 +2121,7 @@ icnlikejoinsel(PG_FUNCTION_ARGS)
*/
void
mergejoinscansel(PlannerInfo *root, Node *clause,
- Oid opfamily, int strategy,
+ Oid opfamily, int strategy, bool nulls_first,
Selectivity *leftscan,
Selectivity *rightscan)
{
@@ -2214,18 +2214,39 @@ mergejoinscansel(PlannerInfo *root, Node *clause,
/*
* Now, the fraction of the left variable that will be scanned is the
* fraction that's <= the right-side maximum value. But only believe
- * non-default estimates, else stick with our 1.0.
+ * non-default estimates, else stick with our 1.0. Also, if the sort
+ * order is nulls-first, we're going to have to read over any nulls too.
*/
selec = scalarineqsel(root, leop, false, &leftvar,
rightmax, op_righttype);
if (selec != DEFAULT_INEQ_SEL)
+ {
+ if (nulls_first && HeapTupleIsValid(leftvar.statsTuple))
+ {
+ Form_pg_statistic stats;
+
+ stats = (Form_pg_statistic) GETSTRUCT(leftvar.statsTuple);
+ selec += stats->stanullfrac;
+ CLAMP_PROBABILITY(selec);
+ }
*leftscan = selec;
+ }
/* And similarly for the right variable. */
selec = scalarineqsel(root, revleop, false, &rightvar,
leftmax, op_lefttype);
if (selec != DEFAULT_INEQ_SEL)
+ {
+ if (nulls_first && HeapTupleIsValid(rightvar.statsTuple))
+ {
+ Form_pg_statistic stats;
+
+ stats = (Form_pg_statistic) GETSTRUCT(rightvar.statsTuple);
+ selec += stats->stanullfrac;
+ CLAMP_PROBABILITY(selec);
+ }
*rightscan = selec;
+ }
/*
* Only one of the two fractions can really be less than 1.0; believe the
diff --git a/src/include/nodes/relation.h b/src/include/nodes/relation.h
index a83a20d21b59cec6f4c9086cfb360078bf0ce508..c67c067a5f239e9d6de844d21452f402af4fa92b 100644
--- a/src/include/nodes/relation.h
+++ b/src/include/nodes/relation.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.133 2007/01/20 20:45:40 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/relation.h,v 1.134 2007/01/22 20:00:40 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -397,6 +397,7 @@ typedef struct EquivalenceClass
List *ec_opfamilies; /* btree operator family OIDs */
List *ec_members; /* list of EquivalenceMembers */
List *ec_sources; /* list of generating RestrictInfos */
+ List *ec_derives; /* list of derived RestrictInfos */
Relids ec_relids; /* all relids appearing in ec_members */
bool ec_has_const; /* any pseudoconstants in ec_members? */
bool ec_has_volatile; /* the (sole) member is a volatile expr */
@@ -890,6 +891,9 @@ typedef struct RestrictInfo
/* cache space for mergeclause processing; NULL if not yet set */
EquivalenceClass *left_ec; /* EquivalenceClass containing lefthand */
EquivalenceClass *right_ec; /* EquivalenceClass containing righthand */
+ EquivalenceMember *left_em; /* EquivalenceMember for lefthand */
+ EquivalenceMember *right_em; /* EquivalenceMember for righthand */
+ List *scansel_cache; /* list of MergeScanSelCache structs */
/* transient workspace for use while considering a specific join path */
bool outer_is_left; /* T = outer var on left, F = on right */
@@ -902,6 +906,24 @@ typedef struct RestrictInfo
Selectivity right_bucketsize; /* avg bucketsize of right side */
} RestrictInfo;
+/*
+ * Since mergejoinscansel() is a relatively expensive function, and would
+ * otherwise be invoked many times while planning a large join tree,
+ * we go out of our way to cache its results. Each mergejoinable
+ * RestrictInfo carries a list of the specific sort orderings that have
+ * been considered for use with it, and the resulting selectivities.
+ */
+typedef struct MergeScanSelCache
+{
+ /* Ordering details (cache lookup key) */
+ Oid opfamily; /* btree opfamily defining the ordering */
+ int strategy; /* sort direction (ASC or DESC) */
+ bool nulls_first; /* do NULLs come before normal values? */
+ /* Results */
+ Selectivity leftscansel; /* scan fraction for clause left side */
+ Selectivity rightscansel; /* scan fraction for clause right side */
+} MergeScanSelCache;
+
/*
* Inner indexscan info.
*
diff --git a/src/include/utils/selfuncs.h b/src/include/utils/selfuncs.h
index 84549ca1d32092a2f0cfaa6bcfe2ca307ee8dfff..f0c6f20427c23e57b230f3d1f164e36d0f32e115 100644
--- a/src/include/utils/selfuncs.h
+++ b/src/include/utils/selfuncs.h
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/utils/selfuncs.h,v 1.38 2007/01/05 22:19:59 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/utils/selfuncs.h,v 1.39 2007/01/22 20:00:40 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -160,7 +160,7 @@ extern Selectivity rowcomparesel(PlannerInfo *root,
int varRelid, JoinType jointype);
extern void mergejoinscansel(PlannerInfo *root, Node *clause,
- Oid opfamily, int strategy,
+ Oid opfamily, int strategy, bool nulls_first,
Selectivity *leftscan,
Selectivity *rightscan);