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Further tweaking of parsetree & plantree representation of SubLinks.

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Simplify SubLink by storing just a List of operator OIDs, instead of
a list of incomplete OpExprs --- that was a bizarre and bulky choice,
with no redeeming social value since we have to build new OpExprs
anyway when forming the plan tree.
This commit is contained in:
Tom Lane
2003-01-10 21:08:15 +00:00
parent 36ea26793a
commit e69785debf
17 changed files with 407 additions and 246 deletions
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66
src/backend/optimizer/util/clauses.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.120 2002/12/15 16:17:50 tgl Exp $
* $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.121 2003/01/10 21:08:13 tgl Exp $
*
* HISTORY
* AUTHOR DATE MAJOR EVENT
@@ -721,7 +721,7 @@ check_subplans_for_ungrouped_vars_walker(Node *node,
* mistakenly think that something like "WHERE random() < 0.5" can be treated
* as a constant qualification.
*
* XXX we do not examine sublinks/subplans to see if they contain uses of
* XXX we do not examine sub-selects to see if they contain uses of
* mutable functions. It's not real clear if that is correct or not...
*/
bool
@@ -759,6 +759,18 @@ contain_mutable_functions_walker(Node *node, void *context)
return true;
/* else fall through to check args */
}
if (IsA(node, SubLink))
{
SubLink *sublink = (SubLink *) node;
List *opid;
foreach(opid, sublink->operOids)
{
if (op_volatile((Oid) lfirsti(opid)) != PROVOLATILE_IMMUTABLE)
return true;
}
/* else fall through to check args */
}
return expression_tree_walker(node, contain_mutable_functions_walker,
context);
}
@@ -776,7 +788,7 @@ contain_mutable_functions_walker(Node *node, void *context)
* volatile function) is found. This test prevents invalid conversions
* of volatile expressions into indexscan quals.
*
* XXX we do not examine sublinks/subplans to see if they contain uses of
* XXX we do not examine sub-selects to see if they contain uses of
* volatile functions. It's not real clear if that is correct or not...
*/
bool
@@ -814,6 +826,18 @@ contain_volatile_functions_walker(Node *node, void *context)
return true;
/* else fall through to check args */
}
if (IsA(node, SubLink))
{
SubLink *sublink = (SubLink *) node;
List *opid;
foreach(opid, sublink->operOids)
{
if (op_volatile((Oid) lfirsti(opid)) == PROVOLATILE_VOLATILE)
return true;
}
/* else fall through to check args */
}
return expression_tree_walker(node, contain_volatile_functions_walker,
context);
}
@@ -830,7 +854,7 @@ contain_volatile_functions_walker(Node *node, void *context)
* Returns true if any nonstrict construct is found --- ie, anything that
* could produce non-NULL output with a NULL input.
*
* XXX we do not examine sublinks/subplans to see if they contain uses of
* XXX we do not examine sub-selects to see if they contain uses of
* nonstrict functions. It's not real clear if that is correct or not...
* for the current usage it does not matter, since inline_function()
* rejects cases with sublinks.
@@ -887,6 +911,18 @@ contain_nonstrict_functions_walker(Node *node, void *context)
return true;
if (IsA(node, BooleanTest))
return true;
if (IsA(node, SubLink))
{
SubLink *sublink = (SubLink *) node;
List *opid;
foreach(opid, sublink->operOids)
{
if (!op_strict((Oid) lfirsti(opid)))
return true;
}
/* else fall through to check args */
}
return expression_tree_walker(node, contain_nonstrict_functions_walker,
context);
}
@@ -2130,8 +2166,8 @@ substitute_actual_parameters_mutator(Node *node,
* walker on all the expression subtrees of the given Query node.
*
* expression_tree_walker will handle SubPlan nodes by recursing normally
* into the "oper" and "args" lists (which are expressions belonging to the
* outer plan). It will not touch the completed subplan, however. Since
* into the "exprs" and "args" lists (which are expressions belonging to
* the outer plan). It will not touch the completed subplan, however. Since
* there is no link to the original Query, it is not possible to recurse into
* subselects of an already-planned expression tree. This is OK for current
* uses, but may need to be revisited in future.
@@ -2224,11 +2260,6 @@ expression_tree_walker(Node *node,
{
SubLink *sublink = (SubLink *) node;
/*
* We only recurse into the lefthand list (the incomplete
* OpExpr nodes in the oper list are deemed uninteresting,
* perhaps even confusing).
*/
if (expression_tree_walker((Node *) sublink->lefthand,
walker, context))
return true;
@@ -2243,8 +2274,8 @@ expression_tree_walker(Node *node,
{
SubPlan *subplan = (SubPlan *) node;
/* recurse into the oper list, but not into the Plan */
if (expression_tree_walker((Node *) subplan->oper,
/* recurse into the exprs list, but not into the Plan */
if (expression_tree_walker((Node *) subplan->exprs,
walker, context))
return true;
/* also examine args list */
@@ -2451,7 +2482,7 @@ query_tree_walker(Query *query,
* and qualifier clauses during the planning stage.
*
* expression_tree_mutator will handle a SubPlan node by recursing into
* the "oper" and "args" lists (which belong to the outer plan), but it
* the "exprs" and "args" lists (which belong to the outer plan), but it
* will simply copy the link to the inner plan, since that's typically what
* expression tree mutators want. A mutator that wants to modify the subplan
* can force appropriate behavior by recognizing SubPlan expression nodes
@@ -2567,8 +2598,7 @@ expression_tree_mutator(Node *node,
case T_SubLink:
{
/*
* We transform the lefthand side, but not the oper list nor
* the subquery.
* We transform the lefthand side, but not the subquery.
*/
SubLink *sublink = (SubLink *) node;
SubLink *newnode;
@@ -2584,10 +2614,10 @@ expression_tree_mutator(Node *node,
SubPlan *newnode;
FLATCOPY(newnode, subplan, SubPlan);
/* transform exprs list */
MUTATE(newnode->exprs, subplan->exprs, List *);
/* transform args list (params to be passed to subplan) */
MUTATE(newnode->args, subplan->args, List *);
/* transform oper list as well */
MUTATE(newnode->oper, subplan->oper, List *);
/* but not the sub-Plan itself, which is referenced as-is */
return (Node *) newnode;
}