*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.110 2005/05/22 22:30:19 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/plan/setrefs.c,v 1.111 2005/06/10 00:28:54 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "utils/lsyscache.h"
+typedef struct
+{
+ Index varno; /* RT index of Var */
+ AttrNumber varattno; /* attr number of Var */
+ AttrNumber resno; /* TLE position of Var */
+} tlist_vinfo;
+
+typedef struct
+{
+ List *tlist; /* underlying target list */
+ int num_vars; /* number of plain Var tlist entries */
+ bool has_non_vars; /* are there non-plain-Var entries? */
+ /* array of num_vars entries: */
+ tlist_vinfo vars[1]; /* VARIABLE LENGTH ARRAY */
+} indexed_tlist; /* VARIABLE LENGTH STRUCT */
+
typedef struct
{
List *rtable;
- List *outer_tlist;
- List *inner_tlist;
+ indexed_tlist *outer_itlist;
+ indexed_tlist *inner_itlist;
Index acceptable_rel;
- bool tlists_have_non_vars;
} join_references_context;
typedef struct
{
+ indexed_tlist *subplan_itlist;
Index subvarno;
- List *subplan_targetlist;
- bool tlist_has_non_vars;
} replace_vars_with_subplan_refs_context;
static Plan *set_subqueryscan_references(SubqueryScan *plan, List *rtable);
static void set_join_references(Join *join, List *rtable);
static void set_inner_join_references(Plan *inner_plan,
List *rtable,
- List *outer_tlist,
- bool tlists_have_non_vars);
+ indexed_tlist *outer_itlist);
static void set_uppernode_references(Plan *plan, Index subvarno);
-static bool targetlist_has_non_vars(List *tlist);
+static indexed_tlist *build_tlist_index(List *tlist);
+static Var *search_indexed_tlist_for_var(Var *var,
+ indexed_tlist *itlist,
+ Index newvarno);
+static Var *search_indexed_tlist_for_non_var(Node *node,
+ indexed_tlist *itlist,
+ Index newvarno);
static List *join_references(List *clauses,
- List *rtable,
- List *outer_tlist,
- List *inner_tlist,
- Index acceptable_rel,
- bool tlists_have_non_vars);
+ List *rtable,
+ indexed_tlist *outer_itlist,
+ indexed_tlist *inner_itlist,
+ Index acceptable_rel);
static Node *join_references_mutator(Node *node,
join_references_context *context);
static Node *replace_vars_with_subplan_refs(Node *node,
- Index subvarno,
- List *subplan_targetlist,
- bool tlist_has_non_vars);
+ indexed_tlist *subplan_itlist,
+ Index subvarno);
static Node *replace_vars_with_subplan_refs_mutator(Node *node,
replace_vars_with_subplan_refs_context *context);
static bool fix_opfuncids_walker(Node *node, void *context);
{
Plan *outer_plan = join->plan.lefttree;
Plan *inner_plan = join->plan.righttree;
- List *outer_tlist = outer_plan->targetlist;
- List *inner_tlist = inner_plan->targetlist;
- bool tlists_have_non_vars;
+ indexed_tlist *outer_itlist;
+ indexed_tlist *inner_itlist;
- tlists_have_non_vars = targetlist_has_non_vars(outer_tlist) ||
- targetlist_has_non_vars(inner_tlist);
+ outer_itlist = build_tlist_index(outer_plan->targetlist);
+ inner_itlist = build_tlist_index(inner_plan->targetlist);
/* All join plans have tlist, qual, and joinqual */
join->plan.targetlist = join_references(join->plan.targetlist,
rtable,
- outer_tlist,
- inner_tlist,
- (Index) 0,
- tlists_have_non_vars);
+ outer_itlist,
+ inner_itlist,
+ (Index) 0);
join->plan.qual = join_references(join->plan.qual,
rtable,
- outer_tlist,
- inner_tlist,
- (Index) 0,
- tlists_have_non_vars);
+ outer_itlist,
+ inner_itlist,
+ (Index) 0);
join->joinqual = join_references(join->joinqual,
rtable,
- outer_tlist,
- inner_tlist,
- (Index) 0,
- tlists_have_non_vars);
+ outer_itlist,
+ inner_itlist,
+ (Index) 0);
/* Now do join-type-specific stuff */
if (IsA(join, NestLoop))
/* This processing is split out to handle possible recursion */
set_inner_join_references(inner_plan,
rtable,
- outer_tlist,
- tlists_have_non_vars);
+ outer_itlist);
}
else if (IsA(join, MergeJoin))
{
mj->mergeclauses = join_references(mj->mergeclauses,
rtable,
- outer_tlist,
- inner_tlist,
- (Index) 0,
- tlists_have_non_vars);
+ outer_itlist,
+ inner_itlist,
+ (Index) 0);
}
else if (IsA(join, HashJoin))
{
hj->hashclauses = join_references(hj->hashclauses,
rtable,
- outer_tlist,
- inner_tlist,
- (Index) 0,
- tlists_have_non_vars);
+ outer_itlist,
+ inner_itlist,
+ (Index) 0);
}
+
+ pfree(outer_itlist);
+ pfree(inner_itlist);
}
/*
static void
set_inner_join_references(Plan *inner_plan,
List *rtable,
- List *outer_tlist,
- bool tlists_have_non_vars)
+ indexed_tlist *outer_itlist)
{
if (IsA(inner_plan, IndexScan))
{
/* only refs to outer vars get changed in the inner qual */
innerscan->indexqualorig = join_references(indexqualorig,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
innerscan->indexqual = join_references(innerscan->indexqual,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
/*
* We must fix the inner qpqual too, if it has join
if (NumRelids((Node *) inner_plan->qual) > 1)
inner_plan->qual = join_references(inner_plan->qual,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
}
}
else if (IsA(inner_plan, BitmapIndexScan))
/* only refs to outer vars get changed in the inner qual */
innerscan->indexqualorig = join_references(indexqualorig,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
innerscan->indexqual = join_references(innerscan->indexqual,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
/* no need to fix inner qpqual */
Assert(inner_plan->qual == NIL);
}
/* only refs to outer vars get changed in the inner qual */
innerscan->bitmapqualorig = join_references(bitmapqualorig,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
/*
* We must fix the inner qpqual too, if it has join
if (NumRelids((Node *) inner_plan->qual) > 1)
inner_plan->qual = join_references(inner_plan->qual,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
/* Now recurse */
set_inner_join_references(inner_plan->lefttree,
rtable,
- outer_tlist,
- tlists_have_non_vars);
+ outer_itlist);
}
}
else if (IsA(inner_plan, BitmapAnd))
{
set_inner_join_references((Plan *) lfirst(l),
rtable,
- outer_tlist,
- tlists_have_non_vars);
+ outer_itlist);
}
}
else if (IsA(inner_plan, BitmapOr))
{
set_inner_join_references((Plan *) lfirst(l),
rtable,
- outer_tlist,
- tlists_have_non_vars);
+ outer_itlist);
}
}
else if (IsA(inner_plan, TidScan))
innerscan->tideval = join_references(innerscan->tideval,
rtable,
- outer_tlist,
- NIL,
- innerrel,
- tlists_have_non_vars);
+ outer_itlist,
+ NULL,
+ innerrel);
}
}
set_uppernode_references(Plan *plan, Index subvarno)
{
Plan *subplan = plan->lefttree;
- List *subplan_targetlist,
- *output_targetlist;
+ indexed_tlist *subplan_itlist;
+ List *output_targetlist;
ListCell *l;
- bool tlist_has_non_vars;
if (subplan != NULL)
- subplan_targetlist = subplan->targetlist;
+ subplan_itlist = build_tlist_index(subplan->targetlist);
else
- subplan_targetlist = NIL;
-
- tlist_has_non_vars = targetlist_has_non_vars(subplan_targetlist);
+ subplan_itlist = build_tlist_index(NIL);
output_targetlist = NIL;
foreach(l, plan->targetlist)
Node *newexpr;
newexpr = replace_vars_with_subplan_refs((Node *) tle->expr,
- subvarno,
- subplan_targetlist,
- tlist_has_non_vars);
+ subplan_itlist,
+ subvarno);
tle = flatCopyTargetEntry(tle);
tle->expr = (Expr *) newexpr;
output_targetlist = lappend(output_targetlist, tle);
plan->qual = (List *)
replace_vars_with_subplan_refs((Node *) plan->qual,
- subvarno,
- subplan_targetlist,
- tlist_has_non_vars);
+ subplan_itlist,
+ subvarno);
+
+ pfree(subplan_itlist);
}
/*
- * targetlist_has_non_vars --- are there any non-Var entries in tlist?
+ * build_tlist_index --- build an index data structure for a child tlist
*
- * In most cases, subplan tlists will be "flat" tlists with only Vars.
- * Checking for this allows us to save comparisons in common cases.
+ * In most cases, subplan tlists will be "flat" tlists with only Vars,
+ * so we try to optimize that case by extracting information about Vars
+ * in advance. Matching a parent tlist to a child is still an O(N^2)
+ * operation, but at least with a much smaller constant factor than plain
+ * tlist_member() searches.
+ *
+ * The result of this function is an indexed_tlist struct to pass to
+ * search_indexed_tlist_for_var() or search_indexed_tlist_for_non_var().
+ * When done, the indexed_tlist may be freed with a single pfree().
*/
-static bool
-targetlist_has_non_vars(List *tlist)
+static indexed_tlist *
+build_tlist_index(List *tlist)
{
+ indexed_tlist *itlist;
+ tlist_vinfo *vinfo;
ListCell *l;
+ /* Create data structure with enough slots for all tlist entries */
+ itlist = (indexed_tlist *)
+ palloc(offsetof(indexed_tlist, vars) +
+ list_length(tlist) * sizeof(tlist_vinfo));
+
+ itlist->tlist = tlist;
+ itlist->has_non_vars = false;
+
+ /* Find the Vars and fill in the index array */
+ vinfo = itlist->vars;
foreach(l, tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
- if (tle->expr && !IsA(tle->expr, Var))
- return true;
+ if (tle->expr && IsA(tle->expr, Var))
+ {
+ Var *var = (Var *) tle->expr;
+
+ vinfo->varno = var->varno;
+ vinfo->varattno = var->varattno;
+ vinfo->resno = tle->resno;
+ vinfo++;
+ }
+ else
+ itlist->has_non_vars = true;
+ }
+
+ itlist->num_vars = (vinfo - itlist->vars);
+
+ return itlist;
+}
+
+/*
+ * search_indexed_tlist_for_var --- find a Var in an indexed tlist
+ *
+ * If a match is found, return a copy of the given Var with suitably
+ * modified varno/varattno (to wit, newvarno and the resno of the TLE entry).
+ * If no match, return NULL.
+ */
+static Var *
+search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist, Index newvarno)
+{
+ Index varno = var->varno;
+ AttrNumber varattno = var->varattno;
+ tlist_vinfo *vinfo;
+ int i;
+
+ vinfo = itlist->vars;
+ i = itlist->num_vars;
+ while (i-- > 0)
+ {
+ if (vinfo->varno == varno && vinfo->varattno == varattno)
+ {
+ /* Found a match */
+ Var *newvar = (Var *) copyObject(var);
+
+ newvar->varno = newvarno;
+ newvar->varattno = vinfo->resno;
+ return newvar;
+ }
+ vinfo++;
}
- return false;
+ return NULL; /* no match */
+}
+
+/*
+ * search_indexed_tlist_for_non_var --- find a non-Var in an indexed tlist
+ *
+ * If a match is found, return a Var constructed to reference the tlist item.
+ * If no match, return NULL.
+ *
+ * NOTE: it is a waste of time to call this if !itlist->has_non_vars
+ */
+static Var *
+search_indexed_tlist_for_non_var(Node *node,
+ indexed_tlist *itlist, Index newvarno)
+{
+ TargetEntry *tle;
+
+ tle = tlist_member(node, itlist->tlist);
+ if (tle)
+ {
+ /* Found a matching subplan output expression */
+ Var *newvar;
+
+ newvar = makeVar(newvarno,
+ tle->resno,
+ exprType((Node *) tle->expr),
+ exprTypmod((Node *) tle->expr),
+ 0);
+ newvar->varnoold = 0; /* wasn't ever a plain Var */
+ newvar->varoattno = 0;
+ return newvar;
+ }
+ return NULL; /* no match */
}
/*
*
* For a normal join, acceptable_rel should be zero so that any failure to
* match a Var will be reported as an error. For the indexscan case,
- * pass inner_tlist = NIL and acceptable_rel = the ID of the inner relation.
+ * pass inner_itlist = NULL and acceptable_rel = the ID of the inner relation.
*
* 'clauses' is the targetlist or list of join clauses
* 'rtable' is the current range table
- * 'outer_tlist' is the target list of the outer join relation
- * 'inner_tlist' is the target list of the inner join relation, or NIL
+ * 'outer_itlist' is the indexed target list of the outer join relation
+ * 'inner_itlist' is the indexed target list of the inner join relation,
+ * or NULL
* 'acceptable_rel' is either zero or the rangetable index of a relation
* whose Vars may appear in the clause without provoking an error.
*
static List *
join_references(List *clauses,
List *rtable,
- List *outer_tlist,
- List *inner_tlist,
- Index acceptable_rel,
- bool tlists_have_non_vars)
+ indexed_tlist *outer_itlist,
+ indexed_tlist *inner_itlist,
+ Index acceptable_rel)
{
join_references_context context;
context.rtable = rtable;
- context.outer_tlist = outer_tlist;
- context.inner_tlist = inner_tlist;
+ context.outer_itlist = outer_itlist;
+ context.inner_itlist = inner_itlist;
context.acceptable_rel = acceptable_rel;
- context.tlists_have_non_vars = tlists_have_non_vars;
return (List *) join_references_mutator((Node *) clauses, &context);
}
join_references_mutator(Node *node,
join_references_context *context)
{
+ Var *newvar;
+
if (node == NULL)
return NULL;
if (IsA(node, Var))
{
Var *var = (Var *) node;
- TargetEntry *tle;
/* First look for the var in the input tlists */
- tle = tlist_member((Node *) var, context->outer_tlist);
- if (tle)
- {
- Var *newvar = (Var *) copyObject(var);
-
- newvar->varno = OUTER;
- newvar->varattno = tle->resno;
+ newvar = search_indexed_tlist_for_var(var,
+ context->outer_itlist,
+ OUTER);
+ if (newvar)
return (Node *) newvar;
- }
- tle = tlist_member((Node *) var, context->inner_tlist);
- if (tle)
+ if (context->inner_itlist)
{
- Var *newvar = (Var *) copyObject(var);
-
- newvar->varno = INNER;
- newvar->varattno = tle->resno;
- return (Node *) newvar;
+ newvar = search_indexed_tlist_for_var(var,
+ context->inner_itlist,
+ INNER);
+ if (newvar)
+ return (Node *) newvar;
}
/* Return the Var unmodified, if it's for acceptable_rel */
elog(ERROR, "variable not found in subplan target lists");
}
/* Try matching more complex expressions too, if tlists have any */
- if (context->tlists_have_non_vars)
+ if (context->outer_itlist->has_non_vars)
{
- TargetEntry *tle;
-
- tle = tlist_member(node, context->outer_tlist);
- if (tle)
- {
- /* Found a matching subplan output expression */
- Var *newvar;
-
- newvar = makeVar(OUTER,
- tle->resno,
- exprType((Node *) tle->expr),
- exprTypmod((Node *) tle->expr),
- 0);
- newvar->varnoold = 0; /* wasn't ever a plain Var */
- newvar->varoattno = 0;
+ newvar = search_indexed_tlist_for_non_var(node,
+ context->outer_itlist,
+ OUTER);
+ if (newvar)
return (Node *) newvar;
- }
- tle = tlist_member(node, context->inner_tlist);
- if (tle)
- {
- /* Found a matching subplan output expression */
- Var *newvar;
-
- newvar = makeVar(INNER,
- tle->resno,
- exprType((Node *) tle->expr),
- exprTypmod((Node *) tle->expr),
- 0);
- newvar->varnoold = 0; /* wasn't ever a plain Var */
- newvar->varoattno = 0;
+ }
+ if (context->inner_itlist && context->inner_itlist->has_non_vars)
+ {
+ newvar = search_indexed_tlist_for_non_var(node,
+ context->inner_itlist,
+ INNER);
+ if (newvar)
return (Node *) newvar;
- }
}
return expression_tree_mutator(node,
join_references_mutator,
* --- so this routine should only be applied to nodes whose subplans'
* targetlists were generated via flatten_tlist() or some such method.
*
- * If tlist_has_non_vars is true, then we try to match whole subexpressions
+ * If itlist->has_non_vars is true, then we try to match whole subexpressions
* against elements of the subplan tlist, so that we can avoid recomputing
* expressions that were already computed by the subplan. (This is relatively
* expensive, so we don't want to try it in the common case where the
* subplan tlist is just a flattened list of Vars.)
*
* 'node': the tree to be fixed (a target item or qual)
+ * 'subplan_itlist': indexed target list for subplan
* 'subvarno': varno to be assigned to all Vars
- * 'subplan_targetlist': target list for subplan
- * 'tlist_has_non_vars': true if subplan_targetlist contains non-Var exprs
*
* The resulting tree is a copy of the original in which all Var nodes have
* varno = subvarno, varattno = resno of corresponding subplan target.
*/
static Node *
replace_vars_with_subplan_refs(Node *node,
- Index subvarno,
- List *subplan_targetlist,
- bool tlist_has_non_vars)
+ indexed_tlist *subplan_itlist,
+ Index subvarno)
{
replace_vars_with_subplan_refs_context context;
+ context.subplan_itlist = subplan_itlist;
context.subvarno = subvarno;
- context.subplan_targetlist = subplan_targetlist;
- context.tlist_has_non_vars = tlist_has_non_vars;
return replace_vars_with_subplan_refs_mutator(node, &context);
}
replace_vars_with_subplan_refs_mutator(Node *node,
replace_vars_with_subplan_refs_context *context)
{
+ Var *newvar;
+
if (node == NULL)
return NULL;
if (IsA(node, Var))
{
Var *var = (Var *) node;
- TargetEntry *tle;
- Var *newvar;
- tle = tlist_member((Node *) var, context->subplan_targetlist);
- if (!tle)
+ newvar = search_indexed_tlist_for_var(var,
+ context->subplan_itlist,
+ context->subvarno);
+ if (!newvar)
elog(ERROR, "variable not found in subplan target list");
- newvar = (Var *) copyObject(var);
- newvar->varno = context->subvarno;
- newvar->varattno = tle->resno;
return (Node *) newvar;
}
/* Try matching more complex expressions too, if tlist has any */
- if (context->tlist_has_non_vars)
+ if (context->subplan_itlist->has_non_vars)
{
- TargetEntry *tle;
-
- tle = tlist_member(node, context->subplan_targetlist);
- if (tle)
- {
- /* Found a matching subplan output expression */
- Var *newvar;
-
- newvar = makeVar(context->subvarno,
- tle->resno,
- exprType((Node *) tle->expr),
- exprTypmod((Node *) tle->expr),
- 0);
- newvar->varnoold = 0; /* wasn't ever a plain Var */
- newvar->varoattno = 0;
+ newvar = search_indexed_tlist_for_non_var(node,
+ context->subplan_itlist,
+ context->subvarno);
+ if (newvar)
return (Node *) newvar;
- }
}
return expression_tree_mutator(node,
replace_vars_with_subplan_refs_mutator,
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