diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c
index e896b479018b718d2094e8d6d8a53c45e25e35ec..bf9e5c10d6f0c3f6531a71643275b733d9126259 100644
--- a/src/backend/nodes/list.c
+++ b/src/backend/nodes/list.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.44 2003/01/20 18:54:47 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.45 2003/01/24 03:58:34 tgl Exp $
*
* NOTES
* XXX a few of the following functions are duplicated to handle
@@ -357,6 +357,7 @@ set_union(List *l1, List *l2)
return retval;
}
+/* set_union for integer lists */
List *
set_unioni(List *l1, List *l2)
{
@@ -371,6 +372,21 @@ set_unioni(List *l1, List *l2)
return retval;
}
+/* set_union when pointer-equality comparison is sufficient */
+List *
+set_ptrUnion(List *l1, List *l2)
+{
+ List *retval = listCopy(l1);
+ List *i;
+
+ foreach(i, l2)
+ {
+ if (!ptrMember(lfirst(i), retval))
+ retval = lappend(retval, lfirst(i));
+ }
+ return retval;
+}
+
/*
* Generate the intersection of two lists,
* ie, all members of both l1 and l2.
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
index 02a92fd99605d5ef26dc13c0e50dc3b288d45b10..443d54c64733ba0ed20edaf1151257e5460e6a49 100644
--- a/src/backend/optimizer/path/indxpath.c
+++ b/src/backend/optimizer/path/indxpath.c
@@ -9,7 +9,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.132 2003/01/20 18:54:49 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/indxpath.c,v 1.133 2003/01/24 03:58:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1596,12 +1596,14 @@ make_innerjoin_index_path(Query *root,
* nconc the two lists; then we might have some restriction
* clauses appearing twice, which'd mislead
* restrictlist_selectivity into double-counting their
- * selectivity.)
+ * selectivity. However, since RestrictInfo nodes aren't copied when
+ * linking them into different lists, it should be sufficient to use
+ * pointer comparison to remove duplicates.)
*/
pathnode->rows = rel->tuples *
restrictlist_selectivity(root,
- set_union(rel->baserestrictinfo,
- clausegroup),
+ set_ptrUnion(rel->baserestrictinfo,
+ clausegroup),
lfirsti(rel->relids));
/* Like costsize.c, force estimate to be at least one row */
if (pathnode->rows < 1.0)
diff --git a/src/backend/optimizer/path/pathkeys.c b/src/backend/optimizer/path/pathkeys.c
index 194bdddc2f09c1b151b3f64053331e9c3b0e7157..b99a44a440420d99b0c995fa8ea04ac20e486999 100644
--- a/src/backend/optimizer/path/pathkeys.c
+++ b/src/backend/optimizer/path/pathkeys.c
@@ -11,7 +11,7 @@
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.44 2003/01/15 19:35:40 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/path/pathkeys.c,v 1.45 2003/01/24 03:58:35 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -23,6 +23,7 @@
#include "optimizer/paths.h"
#include "optimizer/planmain.h"
#include "optimizer/tlist.h"
+#include "optimizer/var.h"
#include "parser/parsetree.h"
#include "parser/parse_func.h"
#include "utils/lsyscache.h"
@@ -147,14 +148,30 @@ add_equijoined_keys(Query *root, RestrictInfo *restrictinfo)
* generate_implied_equalities
* Scan the completed equi_key_list for the query, and generate explicit
* qualifications (WHERE clauses) for all the pairwise equalities not
- * already mentioned in the quals. This is useful because the additional
- * clauses help the selectivity-estimation code, and in fact it's
- * *necessary* to ensure that sort keys we think are equivalent really
- * are (see src/backend/optimizer/README for more info).
+ * already mentioned in the quals; or remove qualifications found to be
+ * redundant.
+ *
+ * Adding deduced equalities is useful because the additional clauses help
+ * the selectivity-estimation code and may allow better joins to be chosen;
+ * and in fact it's *necessary* to ensure that sort keys we think are
+ * equivalent really are (see src/backend/optimizer/README for more info).
+ *
+ * If an equi_key_list set includes any constants then we adopt a different
+ * strategy: we record all the "var = const" deductions we can make, and
+ * actively remove all the "var = var" clauses that are implied by the set
+ * (including the clauses that originally gave rise to the set!). The reason
+ * is that given input like "a = b AND b = 42", once we have deduced "a = 42"
+ * there is no longer any need to apply the clause "a = b"; not only is
+ * it a waste of time to check it, but we will misestimate selectivity if the
+ * clause is left in. So we must remove it. For this purpose, any pathkey
+ * item that mentions no Vars of the current level can be taken as a constant.
+ * (The only case where this would be risky is if the item contains volatile
+ * functions; but we will never consider such an expression to be a pathkey
+ * at all, because check_mergejoinable() will reject it.)
*
* This routine just walks the equi_key_list to find all pairwise equalities.
- * We call process_implied_equality (in plan/initsplan.c) to determine whether
- * each is already known and add it to the proper restrictinfo list if not.
+ * We call process_implied_equality (in plan/initsplan.c) to adjust the
+ * restrictinfo datastructures for each pair.
*/
void
generate_implied_equalities(Query *root)
@@ -164,35 +181,119 @@ generate_implied_equalities(Query *root)
foreach(cursetlink, root->equi_key_list)
{
List *curset = lfirst(cursetlink);
+ int nitems = length(curset);
+ Relids *relids;
+ bool have_consts;
List *ptr1;
+ int i1;
/*
* A set containing only two items cannot imply any equalities
* beyond the one that created the set, so we can skip it.
*/
- if (length(curset) < 3)
+ if (nitems < 3)
continue;
+ /*
+ * Collect info about relids mentioned in each item. For this
+ * routine we only really care whether there are any at all in
+ * each item, but process_implied_equality() needs the exact
+ * lists, so we may as well pull them here.
+ */
+ relids = (Relids *) palloc(nitems * sizeof(Relids));
+ have_consts = false;
+ i1 = 0;
+ foreach(ptr1, curset)
+ {
+ PathKeyItem *item1 = (PathKeyItem *) lfirst(ptr1);
+
+ relids[i1] = pull_varnos(item1->key);
+ if (relids[i1] == NIL)
+ have_consts = true;
+ i1++;
+ }
+
/*
* Match each item in the set with all that appear after it (it's
* sufficient to generate A=B, need not process B=A too).
*/
+ i1 = 0;
foreach(ptr1, curset)
{
PathKeyItem *item1 = (PathKeyItem *) lfirst(ptr1);
List *ptr2;
+ int i2 = i1 + 1;
foreach(ptr2, lnext(ptr1))
{
PathKeyItem *item2 = (PathKeyItem *) lfirst(ptr2);
- process_implied_equality(root, item1->key, item2->key,
- item1->sortop, item2->sortop);
+ /*
+ * If it's "const = const" then just ignore it altogether.
+ * There is no place in the restrictinfo structure to store
+ * it. (If the two consts are in fact unequal, then
+ * propagating the comparison to Vars will cause us to
+ * produce zero rows out, as expected.)
+ */
+ if (relids[i1] != NIL || relids[i2] != NIL)
+ {
+ /*
+ * Tell process_implied_equality to delete the clause,
+ * not add it, if it's "var = var" and we have constants
+ * present in the list.
+ */
+ bool delete_it = (have_consts &&
+ relids[i1] != NIL &&
+ relids[i2] != NIL);
+ process_implied_equality(root,
+ item1->key, item2->key,
+ item1->sortop, item2->sortop,
+ relids[i1], relids[i2],
+ delete_it);
+ }
+ i2++;
}
+ i1++;
+ }
+ }
+}
+
+/*
+ * exprs_known_equal
+ * Detect whether two expressions are known equal due to equijoin clauses.
+ *
+ * Note: does not bother to check for "equal(item1, item2)"; caller must
+ * check that case if it's possible to pass identical items.
+ */
+bool
+exprs_known_equal(Query *root, Node *item1, Node *item2)
+{
+ List *cursetlink;
+
+ foreach(cursetlink, root->equi_key_list)
+ {
+ List *curset = lfirst(cursetlink);
+ bool item1member = false;
+ bool item2member = false;
+ List *ptr;
+
+ foreach(ptr, curset)
+ {
+ PathKeyItem *pitem = (PathKeyItem *) lfirst(ptr);
+
+ if (equal(item1, pitem->key))
+ item1member = true;
+ else if (equal(item2, pitem->key))
+ item2member = true;
+ /* Exit as soon as equality is proven */
+ if (item1member && item2member)
+ return true;
}
}
+ return false;
}
+
/*
* make_canonical_pathkey
* Given a PathKeyItem, find the equi_key_list subset it is a member of,
diff --git a/src/backend/optimizer/plan/initsplan.c b/src/backend/optimizer/plan/initsplan.c
index 037ed3314cf866e6087164187c6a36fa4587f7e9..3a824d55d72b7bd1c6d2d06bd33f96770efb118f 100644
--- a/src/backend/optimizer/plan/initsplan.c
+++ b/src/backend/optimizer/plan/initsplan.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.82 2003/01/20 18:54:52 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.83 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -40,8 +40,6 @@ static void distribute_qual_to_rels(Query *root, Node *clause,
bool isouterjoin,
bool isdeduced,
Relids qualscope);
-static void add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo,
- Relids join_relids);
static void add_vars_to_targetlist(Query *root, List *vars);
static bool qual_is_redundant(Query *root, RestrictInfo *restrictinfo,
List *restrictlist);
@@ -539,7 +537,7 @@ distribute_qual_to_rels(Query *root, Node *clause,
/*
* Add clause to the join lists of all the relevant relations.
*/
- add_join_info_to_rels(root, restrictinfo, relids);
+ add_join_clause_to_rels(root, restrictinfo, relids);
/*
* Add vars used in the join clause to targetlists of their
@@ -572,79 +570,96 @@ distribute_qual_to_rels(Query *root, Node *clause,
add_equijoined_keys(root, restrictinfo);
}
-/*
- * add_join_info_to_rels
- * For every relation participating in a join clause, add 'restrictinfo' to
- * the appropriate joininfo list (creating a new list and adding it to the
- * appropriate rel node if necessary).
- *
- * Note that the same copy of the restrictinfo node is linked to by all the
- * lists it is in. This allows us to exploit caching of information about
- * the restriction clause (but we must be careful that the information does
- * not depend on context).
- *
- * 'restrictinfo' describes the join clause
- * 'join_relids' is the list of relations participating in the join clause
- */
-static void
-add_join_info_to_rels(Query *root, RestrictInfo *restrictinfo,
- Relids join_relids)
-{
- List *join_relid;
-
- /* For every relid, find the joininfo, and add the proper join entries */
- foreach(join_relid, join_relids)
- {
- int cur_relid = lfirsti(join_relid);
- Relids unjoined_relids = NIL;
- JoinInfo *joininfo;
- List *otherrel;
-
- /* Get the relids not equal to the current relid */
- foreach(otherrel, join_relids)
- {
- if (lfirsti(otherrel) != cur_relid)
- unjoined_relids = lappendi(unjoined_relids, lfirsti(otherrel));
- }
- Assert(unjoined_relids != NIL);
-
- /*
- * Find or make the joininfo node for this combination of rels,
- * and add the restrictinfo node to it.
- */
- joininfo = make_joininfo_node(find_base_rel(root, cur_relid),
- unjoined_relids);
- joininfo->jinfo_restrictinfo = lappend(joininfo->jinfo_restrictinfo,
- restrictinfo);
- }
-}
-
/*
* process_implied_equality
* Check to see whether we already have a restrictinfo item that says
- * item1 = item2, and create one if not. This is a consequence of
- * transitivity of mergejoin equality: if we have mergejoinable
- * clauses A = B and B = C, we can deduce A = C (where = is an
- * appropriate mergejoinable operator).
+ * item1 = item2, and create one if not; or if delete_it is true,
+ * remove any such restrictinfo item.
+ *
+ * This processing is a consequence of transitivity of mergejoin equality:
+ * if we have mergejoinable clauses A = B and B = C, we can deduce A = C
+ * (where = is an appropriate mergejoinable operator). See path/pathkeys.c
+ * for more details.
*/
void
-process_implied_equality(Query *root, Node *item1, Node *item2,
- Oid sortop1, Oid sortop2)
+process_implied_equality(Query *root,
+ Node *item1, Node *item2,
+ Oid sortop1, Oid sortop2,
+ Relids item1_relids, Relids item2_relids,
+ bool delete_it)
{
+ Relids relids;
+ RelOptInfo *rel1;
+ List *restrictlist;
+ List *itm;
Oid ltype,
rtype;
Operator eq_operator;
Form_pg_operator pgopform;
Expr *clause;
+ /* Get list of relids referenced in the two expressions */
+ relids = set_unioni(item1_relids, item2_relids);
+
/*
- * Forget it if this equality is already recorded.
- *
- * Note: if only a single relation is involved, we may fall through
- * here and end up rejecting the equality later on in qual_is_redundant.
- * This is a tad slow but should be okay.
+ * generate_implied_equalities() shouldn't call me on two constants.
+ */
+ Assert(relids != NIL);
+
+ /*
+ * If the exprs involve a single rel, we need to look at that rel's
+ * baserestrictinfo list. If multiple rels, any one will have a
+ * joininfo node for the rest, and we can scan any of 'em.
*/
- if (exprs_known_equal(root, item1, item2))
+ rel1 = find_base_rel(root, lfirsti(relids));
+ if (lnext(relids) == NIL)
+ restrictlist = rel1->baserestrictinfo;
+ else
+ {
+ JoinInfo *joininfo = find_joininfo_node(rel1, lnext(relids));
+
+ restrictlist = joininfo ? joininfo->jinfo_restrictinfo : NIL;
+ }
+
+ /*
+ * Scan to see if equality is already known. If so, we're done in
+ * the add case, and done after removing it in the delete case.
+ */
+ foreach(itm, restrictlist)
+ {
+ RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(itm);
+ Node *left,
+ *right;
+
+ if (restrictinfo->mergejoinoperator == InvalidOid)
+ continue; /* ignore non-mergejoinable clauses */
+ /* We now know the restrictinfo clause is a binary opclause */
+ left = get_leftop(restrictinfo->clause);
+ right = get_rightop(restrictinfo->clause);
+ if ((equal(item1, left) && equal(item2, right)) ||
+ (equal(item2, left) && equal(item1, right)))
+ {
+ /* found a matching clause */
+ if (delete_it)
+ {
+ if (lnext(relids) == NIL)
+ {
+ /* delete it from local restrictinfo list */
+ rel1->baserestrictinfo = lremove(restrictinfo,
+ rel1->baserestrictinfo);
+ }
+ else
+ {
+ /* let joininfo.c do it */
+ remove_join_clause_from_rels(root, restrictinfo, relids);
+ }
+ }
+ return; /* done */
+ }
+ }
+
+ /* Didn't find it. Done if deletion requested */
+ if (delete_it)
return;
/*
@@ -692,73 +707,7 @@ process_implied_equality(Query *root, Node *item1, Node *item2,
*/
distribute_qual_to_rels(root, (Node *) clause,
true, false, true,
- pull_varnos((Node *) clause));
-}
-
-/*
- * exprs_known_equal
- * Detect whether two expressions are known equal due to equijoin clauses.
- *
- * This is not completely accurate since we avoid adding redundant restriction
- * clauses to individual base rels (see qual_is_redundant). However, after
- * the implied-equality-deduction phase, it is complete for expressions
- * involving Vars of multiple rels; that's sufficient for planned uses.
- */
-bool
-exprs_known_equal(Query *root, Node *item1, Node *item2)
-{
- List *relids;
- RelOptInfo *rel1;
- List *restrictlist;
- List *itm;
-
- /* Get list of relids referenced in the two expressions */
- relids = set_unioni(pull_varnos(item1), pull_varnos(item2));
-
- /*
- * If there are no Vars at all, say "true". This prevents
- * process_implied_equality from trying to store "const = const"
- * deductions.
- */
- if (relids == NIL)
- return true;
-
- /*
- * If the exprs involve a single rel, we need to look at that rel's
- * baserestrictinfo list. If multiple rels, any one will have a
- * joininfo node for the rest, and we can scan any of 'em.
- */
- rel1 = find_base_rel(root, lfirsti(relids));
- relids = lnext(relids);
- if (relids == NIL)
- restrictlist = rel1->baserestrictinfo;
- else
- {
- JoinInfo *joininfo = find_joininfo_node(rel1, relids);
-
- restrictlist = joininfo ? joininfo->jinfo_restrictinfo : NIL;
- }
-
- /*
- * Scan to see if equality is known.
- */
- foreach(itm, restrictlist)
- {
- RestrictInfo *restrictinfo = (RestrictInfo *) lfirst(itm);
- Node *left,
- *right;
-
- if (restrictinfo->mergejoinoperator == InvalidOid)
- continue; /* ignore non-mergejoinable clauses */
- /* We now know the restrictinfo clause is a binary opclause */
- left = get_leftop(restrictinfo->clause);
- right = get_rightop(restrictinfo->clause);
- if ((equal(item1, left) && equal(item2, right)) ||
- (equal(item2, left) && equal(item1, right)))
- return true; /* found a matching clause */
- }
-
- return false;
+ relids);
}
/*
@@ -770,19 +719,32 @@ exprs_known_equal(Query *root, Node *item1, Node *item2)
* SELECT * FROM tab WHERE f1 = f2 AND f2 = f3;
* We need to suppress the redundant condition to avoid computing
* too-small selectivity, not to mention wasting time at execution.
+ *
+ * Note: quals of the form "var = const" are never considered redundant,
+ * only those of the form "var = var". This is needed because when we
+ * have constants in an implied-equality set, we use a different strategy
+ * that suppresses all "var = var" deductions. We must therefore keep
+ * all the "var = const" quals.
*/
static bool
qual_is_redundant(Query *root,
RestrictInfo *restrictinfo,
List *restrictlist)
{
- List *oldquals;
- List *olditem;
Node *newleft;
Node *newright;
+ List *oldquals;
+ List *olditem;
List *equalexprs;
bool someadded;
+ newleft = get_leftop(restrictinfo->clause);
+ newright = get_rightop(restrictinfo->clause);
+
+ /* Never redundant unless vars appear on both sides */
+ if (!contain_var_clause(newleft) || !contain_var_clause(newright))
+ return false;
+
/*
* Set cached pathkeys. NB: it is okay to do this now because this
* routine is only invoked while we are generating implied equalities.
@@ -822,8 +784,6 @@ qual_is_redundant(Query *root,
* we find we can reach the right-side expr of the new qual, we are
* done. We give up when we can't expand the equalexprs list any more.
*/
- newleft = get_leftop(restrictinfo->clause);
- newright = get_rightop(restrictinfo->clause);
equalexprs = makeList1(newleft);
do
{
diff --git a/src/backend/optimizer/util/joininfo.c b/src/backend/optimizer/util/joininfo.c
index c202615b1f5d8304edfd1fe3f6f9976cad80000a..79a9f7a3bac35d7d67dc21f228324c60fcdc3678 100644
--- a/src/backend/optimizer/util/joininfo.c
+++ b/src/backend/optimizer/util/joininfo.c
@@ -8,13 +8,14 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/joininfo.c,v 1.32 2003/01/20 18:54:56 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/joininfo.c,v 1.33 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "optimizer/joininfo.h"
+#include "optimizer/pathnode.h"
/*
@@ -63,3 +64,110 @@ make_joininfo_node(RelOptInfo *this_rel, Relids join_relids)
}
return joininfo;
}
+
+
+/*
+ * add_join_clause_to_rels
+ * For every relation participating in a join clause, add 'restrictinfo' to
+ * the appropriate joininfo list (creating a new list and adding it to the
+ * appropriate rel node if necessary).
+ *
+ * Note that the same copy of the restrictinfo node is linked to by all the
+ * lists it is in. This allows us to exploit caching of information about
+ * the restriction clause (but we must be careful that the information does
+ * not depend on context).
+ *
+ * 'restrictinfo' describes the join clause
+ * 'join_relids' is the list of relations participating in the join clause
+ * (there must be more than one)
+ */
+void
+add_join_clause_to_rels(Query *root,
+ RestrictInfo *restrictinfo,
+ Relids join_relids)
+{
+ List *join_relid;
+
+ /* For every relid, find the joininfo, and add the proper join entries */
+ foreach(join_relid, join_relids)
+ {
+ int cur_relid = lfirsti(join_relid);
+ Relids unjoined_relids = NIL;
+ JoinInfo *joininfo;
+ List *otherrel;
+
+ /* Get the relids not equal to the current relid */
+ foreach(otherrel, join_relids)
+ {
+ if (lfirsti(otherrel) != cur_relid)
+ unjoined_relids = lappendi(unjoined_relids, lfirsti(otherrel));
+ }
+ Assert(unjoined_relids != NIL);
+
+ /*
+ * Find or make the joininfo node for this combination of rels,
+ * and add the restrictinfo node to it.
+ */
+ joininfo = make_joininfo_node(find_base_rel(root, cur_relid),
+ unjoined_relids);
+ joininfo->jinfo_restrictinfo = lappend(joininfo->jinfo_restrictinfo,
+ restrictinfo);
+ /*
+ * Can't freeList(unjoined_relids) because new joininfo node may
+ * link to it. We could avoid leaking memory by doing listCopy()
+ * in make_joininfo_node, but for now speed seems better.
+ */
+ }
+}
+
+/*
+ * remove_join_clause_from_rels
+ * Delete 'restrictinfo' from all the joininfo lists it is in
+ *
+ * This reverses the effect of add_join_clause_to_rels. It's used when we
+ * discover that a join clause is redundant.
+ *
+ * 'restrictinfo' describes the join clause
+ * 'join_relids' is the list of relations participating in the join clause
+ * (there must be more than one)
+ */
+void
+remove_join_clause_from_rels(Query *root,
+ RestrictInfo *restrictinfo,
+ Relids join_relids)
+{
+ List *join_relid;
+
+ /* For every relid, find the joininfo */
+ foreach(join_relid, join_relids)
+ {
+ int cur_relid = lfirsti(join_relid);
+ Relids unjoined_relids = NIL;
+ JoinInfo *joininfo;
+ List *otherrel;
+
+ /* Get the relids not equal to the current relid */
+ foreach(otherrel, join_relids)
+ {
+ if (lfirsti(otherrel) != cur_relid)
+ unjoined_relids = lappendi(unjoined_relids, lfirsti(otherrel));
+ }
+ Assert(unjoined_relids != NIL);
+
+ /*
+ * Find the joininfo node for this combination of rels; it should
+ * exist already, if add_join_clause_to_rels was called.
+ */
+ joininfo = find_joininfo_node(find_base_rel(root, cur_relid),
+ unjoined_relids);
+ Assert(joininfo);
+ /*
+ * Remove the restrictinfo from the list. Pointer comparison
+ * is sufficient.
+ */
+ Assert(ptrMember(restrictinfo, joininfo->jinfo_restrictinfo));
+ joininfo->jinfo_restrictinfo = lremove(restrictinfo,
+ joininfo->jinfo_restrictinfo);
+ freeList(unjoined_relids);
+ }
+}
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index 144fac75501947bfd5c511489f26e7eceb934319..06a73bf4e9e3a26021dfde3d6490c579feb26dc7 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/relnode.c,v 1.44 2003/01/20 18:54:56 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/relnode.c,v 1.45 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -549,14 +549,19 @@ subbuild_joinrel_joinlist(RelOptInfo *joinrel,
/*
* These clauses are still join clauses at this level, so find
* or make the appropriate JoinInfo item for the joinrel, and
- * add the clauses to it (eliminating duplicates).
+ * add the clauses to it, eliminating duplicates. (Since
+ * RestrictInfo nodes are normally multiply-linked rather than
+ * copied, pointer equality should be a sufficient test. If
+ * two equal() nodes should happen to sneak in, no great harm
+ * is done --- they'll be detected by redundant-clause testing
+ * when they reach a restriction list.)
*/
JoinInfo *new_joininfo;
new_joininfo = make_joininfo_node(joinrel, new_unjoined_relids);
new_joininfo->jinfo_restrictinfo =
- set_union(new_joininfo->jinfo_restrictinfo,
- joininfo->jinfo_restrictinfo);
+ set_ptrUnion(new_joininfo->jinfo_restrictinfo,
+ joininfo->jinfo_restrictinfo);
}
}
}
diff --git a/src/backend/optimizer/util/restrictinfo.c b/src/backend/optimizer/util/restrictinfo.c
index bc1fcc36464207c76fe16b177384c9174939d28f..bdcc338d609a22fa50f24fb409cdcc896a52b9e1 100644
--- a/src/backend/optimizer/util/restrictinfo.c
+++ b/src/backend/optimizer/util/restrictinfo.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.15 2002/11/24 21:52:14 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/restrictinfo.c,v 1.16 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -17,6 +17,7 @@
#include "optimizer/clauses.h"
#include "optimizer/paths.h"
#include "optimizer/restrictinfo.h"
+#include "optimizer/var.h"
/*
@@ -101,6 +102,13 @@ get_actual_join_clauses(List *restrictinfo_list,
* equality between any set member on the left and any member on the right;
* by transitivity, all the rest are then equal.
*
+ * However, clauses that are of the form "var expr = const expr" cannot be
+ * eliminated as redundant. This is because when there are const expressions
+ * in a pathkey set, generate_implied_equalities() suppresses "var = var"
+ * clauses in favor of "var = const" clauses. We cannot afford to drop any
+ * of the latter, even though they might seem redundant by the pathkey
+ * membership test.
+ *
* Weird special case: if we have two clauses that seem redundant
* except one is pushed down into an outer join and the other isn't,
* then they're not really redundant, because one constrains the
@@ -120,7 +128,7 @@ remove_redundant_join_clauses(Query *root, List *restrictinfo_list,
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(item);
- /* eliminate duplicates */
+ /* always eliminate duplicates */
if (member(rinfo, result))
continue;
@@ -132,6 +140,7 @@ remove_redundant_join_clauses(Query *root, List *restrictinfo_list,
cache_mergeclause_pathkeys(root, rinfo);
+ /* do the cheap tests first */
foreach(olditem, result)
{
RestrictInfo *oldrinfo = (RestrictInfo *) lfirst(olditem);
@@ -148,7 +157,20 @@ remove_redundant_join_clauses(Query *root, List *restrictinfo_list,
}
if (redundant)
- continue;
+ {
+ /*
+ * It looks redundant, now check for "var = const" case.
+ * If left_relids/right_relids are set, then there are
+ * definitely vars on both sides; else we must check the
+ * hard way.
+ */
+ if (rinfo->left_relids)
+ continue; /* var = var, so redundant */
+ if (contain_var_clause(get_leftop(rinfo->clause)) &&
+ contain_var_clause(get_rightop(rinfo->clause)))
+ continue; /* var = var, so redundant */
+ /* else var = const, not redundant */
+ }
}
/* otherwise, add it to result list */
diff --git a/src/backend/utils/adt/selfuncs.c b/src/backend/utils/adt/selfuncs.c
index 20d353a0a5099f88efd517e2d50c4d6bdb390459..62e0b8b32a9c2f5e8b94fe09d215265678484dc4 100644
--- a/src/backend/utils/adt/selfuncs.c
+++ b/src/backend/utils/adt/selfuncs.c
@@ -15,7 +15,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.128 2003/01/22 20:16:42 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/utils/adt/selfuncs.c,v 1.129 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -84,8 +84,8 @@
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/pathnode.h"
+#include "optimizer/paths.h"
#include "optimizer/plancat.h"
-#include "optimizer/planmain.h"
#include "optimizer/prep.h"
#include "optimizer/tlist.h"
#include "optimizer/var.h"
diff --git a/src/include/nodes/pg_list.h b/src/include/nodes/pg_list.h
index d3b01b7fed0ad00f4c7bc5ca06ae077d38303ac8..56a6640916113066d9053378be3f569a923c4f19 100644
--- a/src/include/nodes/pg_list.h
+++ b/src/include/nodes/pg_list.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: pg_list.h,v 1.31 2003/01/20 18:55:04 tgl Exp $
+ * $Id: pg_list.h,v 1.32 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -141,6 +141,7 @@ extern List *set_differencei(List *list1, List *list2);
extern List *lreverse(List *l);
extern List *set_union(List *list1, List *list2);
extern List *set_unioni(List *list1, List *list2);
+extern List *set_ptrUnion(List *list1, List *list2);
extern List *set_intersecti(List *list1, List *list2);
extern bool equali(List *list1, List *list2);
diff --git a/src/include/optimizer/joininfo.h b/src/include/optimizer/joininfo.h
index 37131b722d2799567e9182c7320f17d1f4c93ffd..6fd806bbaf1bb571a6302abbf29171ccebb19f05 100644
--- a/src/include/optimizer/joininfo.h
+++ b/src/include/optimizer/joininfo.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: joininfo.h,v 1.22 2003/01/20 18:55:04 tgl Exp $
+ * $Id: joininfo.h,v 1.23 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -16,7 +16,15 @@
#include "nodes/relation.h"
-extern JoinInfo *find_joininfo_node(RelOptInfo *this_rel, List *join_relids);
-extern JoinInfo *make_joininfo_node(RelOptInfo *this_rel, List *join_relids);
+
+extern JoinInfo *find_joininfo_node(RelOptInfo *this_rel, Relids join_relids);
+extern JoinInfo *make_joininfo_node(RelOptInfo *this_rel, Relids join_relids);
+
+extern void add_join_clause_to_rels(Query *root,
+ RestrictInfo *restrictinfo,
+ Relids join_relids);
+extern void remove_join_clause_from_rels(Query *root,
+ RestrictInfo *restrictinfo,
+ Relids join_relids);
#endif /* JOININFO_H */
diff --git a/src/include/optimizer/paths.h b/src/include/optimizer/paths.h
index 7ed5b403a87c1bc1f2b1798b412c7c35f01d5a4b..76285bac408c63d53bde46e517fd935f2ac7b304 100644
--- a/src/include/optimizer/paths.h
+++ b/src/include/optimizer/paths.h
@@ -8,7 +8,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: paths.h,v 1.63 2002/12/16 21:30:30 tgl Exp $
+ * $Id: paths.h,v 1.64 2003/01/24 03:58:43 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -17,6 +17,7 @@
#include "nodes/relation.h"
+
/* default GEQO threshold (default value for geqo_rels) */
/* If you change this, update backend/utils/misc/postgresql.sample.conf */
#define DEFAULT_GEQO_RELS 11
@@ -92,6 +93,7 @@ typedef enum
} PathKeysComparison;
extern void add_equijoined_keys(Query *root, RestrictInfo *restrictinfo);
+extern bool exprs_known_equal(Query *root, Node *item1, Node *item2);
extern void generate_implied_equalities(Query *root);
extern List *canonicalize_pathkeys(Query *root, List *pathkeys);
extern PathKeysComparison compare_pathkeys(List *keys1, List *keys2);
diff --git a/src/include/optimizer/planmain.h b/src/include/optimizer/planmain.h
index cf9c2ddeb64315b0e8d2e2b69fab1318075c6b43..399b3bb1310eaafd512c1f33a21cedae04c9dacd 100644
--- a/src/include/optimizer/planmain.h
+++ b/src/include/optimizer/planmain.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $Id: planmain.h,v 1.67 2003/01/20 18:55:05 tgl Exp $
+ * $Id: planmain.h,v 1.68 2003/01/24 03:58:44 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -57,9 +57,11 @@ extern Result *make_result(List *tlist, Node *resconstantqual, Plan *subplan);
extern void add_base_rels_to_query(Query *root, Node *jtnode);
extern void build_base_rel_tlists(Query *root, List *tlist);
extern Relids distribute_quals_to_rels(Query *root, Node *jtnode);
-extern void process_implied_equality(Query *root, Node *item1, Node *item2,
- Oid sortop1, Oid sortop2);
-extern bool exprs_known_equal(Query *root, Node *item1, Node *item2);
+extern void process_implied_equality(Query *root,
+ Node *item1, Node *item2,
+ Oid sortop1, Oid sortop2,
+ Relids item1_relids, Relids item2_relids,
+ bool delete_it);
/*
* prototypes for plan/setrefs.c