*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.38 1999/08/22 20:14:47 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/initsplan.c,v 1.39 1999/08/26 05:07:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
void
make_var_only_tlist(Query *root, List *tlist)
{
- List *tlist_vars = pull_var_clause((Node *) tlist);
+ List *tlist_vars = pull_var_clause((Node *) tlist, false);
add_vars_to_targetlist(root, tlist_vars);
freeList(tlist_vars);
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.65 1999/08/22 23:56:45 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.66 1999/08/26 05:07:41 tgl Exp $
*
*-------------------------------------------------------------------------
*/
/*
* If we have a HAVING clause, do the necessary things with it.
+ * This code should parallel query_planner()'s initial processing
+ * of the WHERE clause.
*/
if (parse->havingQual)
{
List *ql;
- /* convert the havingQual to conjunctive normal form (cnf) */
- parse->havingQual = (Node *) cnfify((Expr *) parse->havingQual, true);
+ /* Replace uplevel Vars with Params */
+ if (PlannerQueryLevel > 1)
+ parse->havingQual = SS_replace_correlation_vars(parse->havingQual);
if (parse->hasSubLinks)
{
- /*
- * There may be a subselect in the havingQual, so we have to
- * process it using the same function as for a subselect in
- * 'where'
- */
+ /* Expand SubLinks to SubPlans */
parse->havingQual = SS_process_sublinks(parse->havingQual);
/*
* Check for ungrouped variables passed to subplans. (Probably
- * this should be done for the targetlist as well???)
+ * this should be done for the targetlist as well??? But we
+ * should NOT do it for the WHERE qual, since WHERE is
+ * evaluated pre-GROUP.)
*/
if (check_subplans_for_ungrouped_vars(parse->havingQual,
parse->groupClause,
elog(ERROR, "Sub-SELECT in HAVING clause must use only GROUPed attributes from outer SELECT");
}
+ /* convert the havingQual to conjunctive normal form (cnf) */
+ parse->havingQual = (Node *) cnfify((Expr *) parse->havingQual, true);
+
/*
* Require an aggregate function to appear in each clause of the
* havingQual (else it could have been done as a WHERE constraint).
/*
* Otherwise, start with a "flattened" tlist (having just the vars
- * mentioned in the targetlist and HAVING qual).
+ * mentioned in the targetlist and HAVING qual --- but not upper-
+ * level Vars; they will be replaced by Params later on).
*/
sub_tlist = flatten_tlist(tlist);
- extravars = pull_var_clause(parse->havingQual);
+ extravars = pull_var_clause(parse->havingQual, false);
sub_tlist = add_to_flat_tlist(sub_tlist, extravars);
freeList(extravars);
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.49 1999/08/25 23:21:41 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.50 1999/08/26 05:09:05 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
/*
* pull_constant_clauses
* Scans through a list of qualifications and find those that
- * contain no variables.
+ * contain no variables (of the current query level).
*
* Returns a list of the constant clauses in constantQual and the remaining
* quals as the return value.
* Var nodes are considered distinct if they have different varno
* or varattno values. If there are several occurrences of the same
* varno/varattno, you get a randomly chosen one...
+ *
+ * Note that upper-level vars are ignored, since they normally will
+ * become Params with respect to this query level.
*/
void
clause_get_relids_vars(Node *clause, Relids *relids, List **vars)
{
- List *clvars = pull_var_clause(clause);
+ List *clvars = pull_var_clause(clause, false);
List *varno_list = NIL;
List *var_list = NIL;
List *i;
Var *var = (Var *) lfirst(i);
List *vi;
- Assert(var->varlevelsup == 0);
if (!intMember(var->varno, varno_list))
varno_list = lconsi(var->varno, varno_list);
foreach(vi, var_list)
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/tlist.c,v 1.40 1999/08/22 20:14:54 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/tlist.c,v 1.41 1999/08/26 05:09:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
* flatten_tlist
* Create a target list that only contains unique variables.
*
+ * Note that Vars with varlevelsup > 0 are not included in the output
+ * tlist. We expect that those will eventually be replaced with Params,
+ * but that probably has not happened at the time this routine is called.
+ *
* 'tlist' is the current target list
*
* Returns the "flattened" new target list.
List *
flatten_tlist(List *tlist)
{
- List *vlist = pull_var_clause((Node *) tlist);
+ List *vlist = pull_var_clause((Node *) tlist, false);
List *new_tlist;
new_tlist = add_to_flat_tlist(NIL, vlist);
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.23 1999/08/22 20:14:54 tgl Exp $
+ * $Header: /cvsroot/pgsql/src/backend/optimizer/util/var.c,v 1.24 1999/08/26 05:09:06 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "optimizer/var.h"
+typedef struct {
+ List *varlist;
+ bool includeUpperVars;
+} pull_var_clause_context;
+
static bool pull_varnos_walker(Node *node, List **listptr);
static bool contain_var_clause_walker(Node *node, void *context);
-static bool pull_var_clause_walker(Node *node, List **listptr);
+static bool pull_var_clause_walker(Node *node,
+ pull_var_clause_context *context);
/*
* pull_varnos
*
* Create a list of all the distinct varnos present in a parsetree
- * (tlist or qual).
+ * (tlist or qual). Note that only varnos attached to level-zero
+ * Vars are considered --- upper Vars refer to some other rtable!
*/
List *
pull_varnos(Node *node)
if (IsA(node, Var))
{
Var *var = (Var *) node;
- if (!intMember(var->varno, *listptr))
+ if (var->varlevelsup == 0 && !intMember(var->varno, *listptr))
*listptr = lconsi(var->varno, *listptr);
return false;
}
/*
* contain_var_clause
- * Recursively scan a clause to discover whether it contains any Var nodes.
+ * Recursively scan a clause to discover whether it contains any Var nodes
+ * (of the current query level).
*
* Returns true if any varnode found.
*/
if (node == NULL)
return false;
if (IsA(node, Var))
- return true; /* abort the tree traversal and return true */
+ {
+ if (((Var *) node)->varlevelsup == 0)
+ return true; /* abort the tree traversal and return true */
+ return false;
+ }
return expression_tree_walker(node, contain_var_clause_walker, context);
}
* pull_var_clause
* Recursively pulls all var nodes from an expression clause.
*
+ * Upper-level vars (with varlevelsup > 0) are included only
+ * if includeUpperVars is true. Most callers probably want
+ * to ignore upper-level vars.
+ *
* Returns list of varnodes found. Note the varnodes themselves are not
* copied, only referenced.
*/
List *
-pull_var_clause(Node *clause)
+pull_var_clause(Node *clause, bool includeUpperVars)
{
- List *result = NIL;
+ pull_var_clause_context context;
- pull_var_clause_walker(clause, &result);
- return result;
+ context.varlist = NIL;
+ context.includeUpperVars = includeUpperVars;
+
+ pull_var_clause_walker(clause, &context);
+ return context.varlist;
}
static bool
-pull_var_clause_walker(Node *node, List **listptr)
+pull_var_clause_walker(Node *node, pull_var_clause_context *context)
{
if (node == NULL)
return false;
if (IsA(node, Var))
{
- *listptr = lappend(*listptr, node);
+ if (((Var *) node)->varlevelsup == 0 || context->includeUpperVars)
+ context->varlist = lappend(context->varlist, node);
return false;
}
return expression_tree_walker(node, pull_var_clause_walker,
- (void *) listptr);
+ (void *) context);
}
*
* Copyright (c) 1994, Regents of the University of California
*
- * $Id: var.h,v 1.9 1999/08/22 20:14:57 tgl Exp $
+ * $Id: var.h,v 1.10 1999/08/26 05:06:17 tgl Exp $
*
*-------------------------------------------------------------------------
*/
extern List *pull_varnos(Node *me);
extern bool contain_var_clause(Node *clause);
-extern List *pull_var_clause(Node *clause);
+extern List *pull_var_clause(Node *clause, bool includeUpperVars);
#endif /* VAR_H */
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