Header And Logo
|
#include "nodes/plannodes.h"#include "nodes/relation.h"
Go to the source code of this file.
Functions | |
| void | SS_process_ctes (PlannerInfo *root) |
| JoinExpr * | convert_ANY_sublink_to_join (PlannerInfo *root, SubLink *sublink, Relids available_rels) |
| JoinExpr * | convert_EXISTS_sublink_to_join (PlannerInfo *root, SubLink *sublink, bool under_not, Relids available_rels) |
| Node * | SS_replace_correlation_vars (PlannerInfo *root, Node *expr) |
| Node * | SS_process_sublinks (PlannerInfo *root, Node *expr, bool isQual) |
| void | SS_finalize_plan (PlannerInfo *root, Plan *plan, bool attach_initplans) |
| Param * | SS_make_initplan_from_plan (PlannerInfo *root, Plan *plan, Oid resulttype, int32 resulttypmod, Oid resultcollation) |
| Param * | assign_nestloop_param_var (PlannerInfo *root, Var *var) |
| Param * | assign_nestloop_param_placeholdervar (PlannerInfo *root, PlaceHolderVar *phv) |
| int | SS_assign_special_param (PlannerInfo *root) |
| Param* assign_nestloop_param_placeholdervar | ( | PlannerInfo * | root, | |
| PlaceHolderVar * | phv | |||
| ) |
Definition at line 275 of file subselect.c.
References Assert, assign_param_for_placeholdervar(), exprCollation(), exprType(), exprTypmod(), i, Param::location, makeNode, Param::paramcollid, Param::paramid, Param::paramkind, Param::paramtype, Param::paramtypmod, PlaceHolderVar::phexpr, and PlaceHolderVar::phlevelsup.
Referenced by replace_nestloop_params_mutator().
{
Param *retval;
int i;
Assert(phv->phlevelsup == 0);
i = assign_param_for_placeholdervar(root, phv);
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
retval->paramid = i;
retval->paramtype = exprType((Node *) phv->phexpr);
retval->paramtypmod = exprTypmod((Node *) phv->phexpr);
retval->paramcollid = exprCollation((Node *) phv->phexpr);
retval->location = -1;
return retval;
}
| Param* assign_nestloop_param_var | ( | PlannerInfo * | root, | |
| Var * | var | |||
| ) |
Definition at line 171 of file subselect.c.
References Assert, assign_param_for_var(), i, Var::location, Param::location, makeNode, Param::paramcollid, Param::paramid, Param::paramkind, Param::paramtype, Param::paramtypmod, Var::varcollid, Var::varlevelsup, Var::vartype, and Var::vartypmod.
Referenced by replace_nestloop_params_mutator().
{
Param *retval;
int i;
Assert(var->varlevelsup == 0);
i = assign_param_for_var(root, var);
retval = makeNode(Param);
retval->paramkind = PARAM_EXEC;
retval->paramid = i;
retval->paramtype = var->vartype;
retval->paramtypmod = var->vartypmod;
retval->paramcollid = var->varcollid;
retval->location = var->location;
return retval;
}
| JoinExpr* convert_ANY_sublink_to_join | ( | PlannerInfo * | root, | |
| SubLink * | sublink, | |||
| Relids | available_rels | |||
| ) |
Definition at line 1165 of file subselect.c.
References addRangeTableEntryForSubquery(), JoinExpr::alias, ANY_SUBLINK, Assert, bms_is_empty(), bms_is_subset(), contain_vars_of_level(), contain_volatile_functions(), convert_testexpr(), generate_subquery_vars(), JoinExpr::isNatural, JoinExpr::jointype, lappend(), JoinExpr::larg, list_length(), makeAlias(), makeNode, NIL, NULL, PlannerInfo::parse, parse(), pull_varnos(), JoinExpr::quals, JoinExpr::rarg, Query::rtable, JoinExpr::rtindex, SubLink::subLinkType, SubLink::subselect, SubLink::testexpr, and JoinExpr::usingClause.
Referenced by pull_up_sublinks_qual_recurse().
{
JoinExpr *result;
Query *parse = root->parse;
Query *subselect = (Query *) sublink->subselect;
Relids upper_varnos;
int rtindex;
RangeTblEntry *rte;
RangeTblRef *rtr;
List *subquery_vars;
Node *quals;
Assert(sublink->subLinkType == ANY_SUBLINK);
/*
* The sub-select must not refer to any Vars of the parent query. (Vars of
* higher levels should be okay, though.)
*/
if (contain_vars_of_level((Node *) subselect, 1))
return NULL;
/*
* The test expression must contain some Vars of the parent query, else
* it's not gonna be a join. (Note that it won't have Vars referring to
* the subquery, rather Params.)
*/
upper_varnos = pull_varnos(sublink->testexpr);
if (bms_is_empty(upper_varnos))
return NULL;
/*
* However, it can't refer to anything outside available_rels.
*/
if (!bms_is_subset(upper_varnos, available_rels))
return NULL;
/*
* The combining operators and left-hand expressions mustn't be volatile.
*/
if (contain_volatile_functions(sublink->testexpr))
return NULL;
/*
* Okay, pull up the sub-select into upper range table.
*
* We rely here on the assumption that the outer query has no references
* to the inner (necessarily true, other than the Vars that we build
* below). Therefore this is a lot easier than what pull_up_subqueries has
* to go through.
*/
rte = addRangeTableEntryForSubquery(NULL,
subselect,
makeAlias("ANY_subquery", NIL),
false,
false);
parse->rtable = lappend(parse->rtable, rte);
rtindex = list_length(parse->rtable);
/*
* Form a RangeTblRef for the pulled-up sub-select.
*/
rtr = makeNode(RangeTblRef);
rtr->rtindex = rtindex;
/*
* Build a list of Vars representing the subselect outputs.
*/
subquery_vars = generate_subquery_vars(root,
subselect->targetList,
rtindex);
/*
* Build the new join's qual expression, replacing Params with these Vars.
*/
quals = convert_testexpr(root, sublink->testexpr, subquery_vars);
/*
* And finally, build the JoinExpr node.
*/
result = makeNode(JoinExpr);
result->jointype = JOIN_SEMI;
result->isNatural = false;
result->larg = NULL; /* caller must fill this in */
result->rarg = (Node *) rtr;
result->usingClause = NIL;
result->quals = quals;
result->alias = NULL;
result->rtindex = 0; /* we don't need an RTE for it */
return result;
}
| JoinExpr* convert_EXISTS_sublink_to_join | ( | PlannerInfo * | root, | |
| SubLink * | sublink, | |||
| bool | under_not, | |||
| Relids | available_rels | |||
| ) |
Definition at line 1266 of file subselect.c.
References JoinExpr::alias, Assert, bms_add_member(), bms_first_member(), bms_free(), bms_is_empty(), bms_is_subset(), contain_vars_of_level(), contain_volatile_functions(), copyObject(), Query::cteList, EXISTS_SUBLINK, FromExpr::fromlist, IncrementVarSublevelsUp(), JoinExpr::isNatural, JOIN_ANTI, Query::jointree, JoinExpr::jointype, JoinExpr::larg, linitial, list_concat(), list_length(), makeNode, NIL, NULL, OffsetVarNodes(), PlannerInfo::parse, parse(), pull_varnos(), JoinExpr::quals, FromExpr::quals, JoinExpr::rarg, Query::rtable, JoinExpr::rtindex, simplify_EXISTS_query(), SubLink::subLinkType, SubLink::subselect, and JoinExpr::usingClause.
Referenced by pull_up_sublinks_qual_recurse().
{
JoinExpr *result;
Query *parse = root->parse;
Query *subselect = (Query *) sublink->subselect;
Node *whereClause;
int rtoffset;
int varno;
Relids clause_varnos;
Relids upper_varnos;
Assert(sublink->subLinkType == EXISTS_SUBLINK);
/*
* Can't flatten if it contains WITH. (We could arrange to pull up the
* WITH into the parent query's cteList, but that risks changing the
* semantics, since a WITH ought to be executed once per associated query
* call.) Note that convert_ANY_sublink_to_join doesn't have to reject
* this case, since it just produces a subquery RTE that doesn't have to
* get flattened into the parent query.
*/
if (subselect->cteList)
return NULL;
/*
* Copy the subquery so we can modify it safely (see comments in
* make_subplan).
*/
subselect = (Query *) copyObject(subselect);
/*
* See if the subquery can be simplified based on the knowledge that it's
* being used in EXISTS(). If we aren't able to get rid of its
* targetlist, we have to fail, because the pullup operation leaves us
* with noplace to evaluate the targetlist.
*/
if (!simplify_EXISTS_query(subselect))
return NULL;
/*
* The subquery must have a nonempty jointree, else we won't have a join.
*/
if (subselect->jointree->fromlist == NIL)
return NULL;
/*
* Separate out the WHERE clause. (We could theoretically also remove
* top-level plain JOIN/ON clauses, but it's probably not worth the
* trouble.)
*/
whereClause = subselect->jointree->quals;
subselect->jointree->quals = NULL;
/*
* The rest of the sub-select must not refer to any Vars of the parent
* query. (Vars of higher levels should be okay, though.)
*/
if (contain_vars_of_level((Node *) subselect, 1))
return NULL;
/*
* On the other hand, the WHERE clause must contain some Vars of the
* parent query, else it's not gonna be a join.
*/
if (!contain_vars_of_level(whereClause, 1))
return NULL;
/*
* We don't risk optimizing if the WHERE clause is volatile, either.
*/
if (contain_volatile_functions(whereClause))
return NULL;
/*
* Prepare to pull up the sub-select into top range table.
*
* We rely here on the assumption that the outer query has no references
* to the inner (necessarily true). Therefore this is a lot easier than
* what pull_up_subqueries has to go through.
*
* In fact, it's even easier than what convert_ANY_sublink_to_join has to
* do. The machinations of simplify_EXISTS_query ensured that there is
* nothing interesting in the subquery except an rtable and jointree, and
* even the jointree FromExpr no longer has quals. So we can just append
* the rtable to our own and use the FromExpr in our jointree. But first,
* adjust all level-zero varnos in the subquery to account for the rtable
* merger.
*/
rtoffset = list_length(parse->rtable);
OffsetVarNodes((Node *) subselect, rtoffset, 0);
OffsetVarNodes(whereClause, rtoffset, 0);
/*
* Upper-level vars in subquery will now be one level closer to their
* parent than before; in particular, anything that had been level 1
* becomes level zero.
*/
IncrementVarSublevelsUp((Node *) subselect, -1, 1);
IncrementVarSublevelsUp(whereClause, -1, 1);
/*
* Now that the WHERE clause is adjusted to match the parent query
* environment, we can easily identify all the level-zero rels it uses.
* The ones <= rtoffset belong to the upper query; the ones > rtoffset do
* not.
*/
clause_varnos = pull_varnos(whereClause);
upper_varnos = NULL;
while ((varno = bms_first_member(clause_varnos)) >= 0)
{
if (varno <= rtoffset)
upper_varnos = bms_add_member(upper_varnos, varno);
}
bms_free(clause_varnos);
Assert(!bms_is_empty(upper_varnos));
/*
* Now that we've got the set of upper-level varnos, we can make the last
* check: only available_rels can be referenced.
*/
if (!bms_is_subset(upper_varnos, available_rels))
return NULL;
/* Now we can attach the modified subquery rtable to the parent */
parse->rtable = list_concat(parse->rtable, subselect->rtable);
/*
* And finally, build the JoinExpr node.
*/
result = makeNode(JoinExpr);
result->jointype = under_not ? JOIN_ANTI : JOIN_SEMI;
result->isNatural = false;
result->larg = NULL; /* caller must fill this in */
/* flatten out the FromExpr node if it's useless */
if (list_length(subselect->jointree->fromlist) == 1)
result->rarg = (Node *) linitial(subselect->jointree->fromlist);
else
result->rarg = (Node *) subselect->jointree;
result->usingClause = NIL;
result->quals = whereClause;
result->alias = NULL;
result->rtindex = 0; /* we don't need an RTE for it */
return result;
}
| int SS_assign_special_param | ( | PlannerInfo * | root | ) |
Definition at line 370 of file subselect.c.
References PlannerInfo::glob, and PlannerGlobal::nParamExec.
Referenced by inheritance_planner(), SS_process_ctes(), and subquery_planner().
{
return root->glob->nParamExec++;
}
| void SS_finalize_plan | ( | PlannerInfo * | root, | |
| Plan * | plan, | |||
| bool | attach_initplans | |||
| ) |
Definition at line 1913 of file subselect.c.
References Plan::allParam, bms_add_member(), bms_add_members(), bms_copy(), bms_del_members(), bms_free(), bms_is_empty(), Plan::extParam, finalize_plan(), PlannerInfo::init_plans, Plan::initPlan, lfirst, lfirst_int, NULL, PlannerParamItem::paramId, PlannerInfo::parent_root, SubPlan::per_call_cost, PlannerInfo::plan_params, planner_subplan_get_plan, SubPlan::setParam, Plan::startup_cost, SubPlan::startup_cost, Plan::total_cost, and PlannerInfo::wt_param_id.
Referenced by SS_make_initplan_from_plan(), and subquery_planner().
{
Bitmapset *valid_params,
*initExtParam,
*initSetParam;
Cost initplan_cost;
PlannerInfo *proot;
ListCell *l;
/*
* Examine any initPlans to determine the set of external params they
* reference, the set of output params they supply, and their total cost.
* We'll use at least some of this info below. (Note we are assuming that
* finalize_plan doesn't touch the initPlans.)
*
* In the case where attach_initplans is false, we are assuming that the
* existing initPlans are siblings that might supply params needed by the
* current plan.
*/
initExtParam = initSetParam = NULL;
initplan_cost = 0;
foreach(l, root->init_plans)
{
SubPlan *initsubplan = (SubPlan *) lfirst(l);
Plan *initplan = planner_subplan_get_plan(root, initsubplan);
ListCell *l2;
initExtParam = bms_add_members(initExtParam, initplan->extParam);
foreach(l2, initsubplan->setParam)
{
initSetParam = bms_add_member(initSetParam, lfirst_int(l2));
}
initplan_cost += initsubplan->startup_cost + initsubplan->per_call_cost;
}
/*
* Now determine the set of params that are validly referenceable in this
* query level; to wit, those available from outer query levels plus the
* output parameters of any local initPlans. (We do not include output
* parameters of regular subplans. Those should only appear within the
* testexpr of SubPlan nodes, and are taken care of locally within
* finalize_primnode. Likewise, special parameters that are generated by
* nodes such as ModifyTable are handled within finalize_plan.)
*/
valid_params = bms_copy(initSetParam);
for (proot = root->parent_root; proot != NULL; proot = proot->parent_root)
{
/* Include ordinary Var/PHV/Aggref params */
foreach(l, proot->plan_params)
{
PlannerParamItem *pitem = (PlannerParamItem *) lfirst(l);
valid_params = bms_add_member(valid_params, pitem->paramId);
}
/* Include any outputs of outer-level initPlans */
foreach(l, proot->init_plans)
{
SubPlan *initsubplan = (SubPlan *) lfirst(l);
ListCell *l2;
foreach(l2, initsubplan->setParam)
{
valid_params = bms_add_member(valid_params, lfirst_int(l2));
}
}
/* Include worktable ID, if a recursive query is being planned */
if (proot->wt_param_id >= 0)
valid_params = bms_add_member(valid_params, proot->wt_param_id);
}
/*
* Now recurse through plan tree.
*/
(void) finalize_plan(root, plan, valid_params, NULL);
bms_free(valid_params);
/*
* Finally, attach any initPlans to the topmost plan node, and add their
* extParams to the topmost node's, too. However, any setParams of the
* initPlans should not be present in the topmost node's extParams, only
* in its allParams. (As of PG 8.1, it's possible that some initPlans
* have extParams that are setParams of other initPlans, so we have to
* take care of this situation explicitly.)
*
* We also add the eval cost of each initPlan to the startup cost of the
* top node. This is a conservative overestimate, since in fact each
* initPlan might be executed later than plan startup, or even not at all.
*/
if (attach_initplans)
{
plan->initPlan = root->init_plans;
root->init_plans = NIL; /* make sure they're not attached twice */
/* allParam must include all these params */
plan->allParam = bms_add_members(plan->allParam, initExtParam);
plan->allParam = bms_add_members(plan->allParam, initSetParam);
/* extParam must include any child extParam */
plan->extParam = bms_add_members(plan->extParam, initExtParam);
/* but extParam shouldn't include any setParams */
plan->extParam = bms_del_members(plan->extParam, initSetParam);
/* ensure extParam is exactly NULL if it's empty */
if (bms_is_empty(plan->extParam))
plan->extParam = NULL;
plan->startup_cost += initplan_cost;
plan->total_cost += initplan_cost;
}
}
| Param* SS_make_initplan_from_plan | ( | PlannerInfo * | root, | |
| Plan * | plan, | |||
| Oid | resulttype, | |||
| int32 | resulttypmod, | |||
| Oid | resultcollation | |||
| ) |
Definition at line 2505 of file subselect.c.
References cost_subplan(), SubPlan::firstColCollation, SubPlan::firstColType, SubPlan::firstColTypmod, generate_new_param(), get_first_col_type(), PlannerInfo::glob, PlannerInfo::init_plans, lappend(), list_length(), list_make1_int, makeNode, palloc(), Param::paramid, SubPlan::plan_id, SubPlan::plan_name, SubPlan::setParam, SS_finalize_plan(), SubPlan::subLinkType, PlannerGlobal::subplans, and PlannerGlobal::subroots.
Referenced by make_agg_subplan().
{
SubPlan *node;
Param *prm;
/*
* We must run SS_finalize_plan(), since that's normally done before a
* subplan gets put into the initplan list. Tell it not to attach any
* pre-existing initplans to this one, since they are siblings not
* children of this initplan. (This is something else that could perhaps
* be cleaner if we did extParam/allParam processing in setrefs.c instead
* of here? See notes for materialize_finished_plan.)
*/
/*
* Build extParam/allParam sets for plan nodes.
*/
SS_finalize_plan(root, plan, false);
/*
* Add the subplan and its PlannerInfo to the global lists.
*/
root->glob->subplans = lappend(root->glob->subplans, plan);
root->glob->subroots = lappend(root->glob->subroots, root);
/*
* Create a SubPlan node and add it to the outer list of InitPlans. Note
* it has to appear after any other InitPlans it might depend on (see
* comments in ExecReScan).
*/
node = makeNode(SubPlan);
node->subLinkType = EXPR_SUBLINK;
get_first_col_type(plan, &node->firstColType, &node->firstColTypmod,
&node->firstColCollation);
node->plan_id = list_length(root->glob->subplans);
root->init_plans = lappend(root->init_plans, node);
/*
* The node can't have any inputs (since it's an initplan), so the
* parParam and args lists remain empty.
*/
cost_subplan(root, node, plan);
/*
* Make a Param that will be the subplan's output.
*/
prm = generate_new_param(root, resulttype, resulttypmod, resultcollation);
node->setParam = list_make1_int(prm->paramid);
/* Label the subplan for EXPLAIN purposes */
node->plan_name = palloc(64);
sprintf(node->plan_name, "InitPlan %d (returns $%d)",
node->plan_id, prm->paramid);
return prm;
}
| void SS_process_ctes | ( | PlannerInfo * | root | ) |
Definition at line 1022 of file subselect.c.
References SubPlan::args, Assert, CMD_SELECT, copyObject(), cost_subplan(), PlannerInfo::cte_plan_ids, Query::cteList, CommonTableExpr::ctename, CommonTableExpr::ctequery, CommonTableExpr::cterecursive, CommonTableExpr::cterefcount, elog, ERROR, SubPlan::firstColCollation, SubPlan::firstColType, SubPlan::firstColTypmod, get_first_col_type(), PlannerInfo::glob, PlannerInfo::init_plans, lappend(), lappend_int(), lfirst, list_length(), list_make1_int, makeNode, NIL, palloc(), SubPlan::paramIds, SubPlan::parParam, PlannerInfo::parse, SubPlan::plan_id, SubPlan::plan_name, PlannerInfo::plan_params, SubPlan::setParam, splan, SS_assign_special_param(), SubPlan::subLinkType, PlannerGlobal::subplans, subquery_planner(), PlannerGlobal::subroots, SubPlan::testexpr, SubPlan::unknownEqFalse, and SubPlan::useHashTable.
Referenced by subquery_planner().
{
ListCell *lc;
Assert(root->cte_plan_ids == NIL);
foreach(lc, root->parse->cteList)
{
CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
CmdType cmdType = ((Query *) cte->ctequery)->commandType;
Query *subquery;
Plan *plan;
PlannerInfo *subroot;
SubPlan *splan;
int paramid;
/*
* Ignore SELECT CTEs that are not actually referenced anywhere.
*/
if (cte->cterefcount == 0 && cmdType == CMD_SELECT)
{
/* Make a dummy entry in cte_plan_ids */
root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
continue;
}
/*
* Copy the source Query node. Probably not necessary, but let's keep
* this similar to make_subplan.
*/
subquery = (Query *) copyObject(cte->ctequery);
/* plan_params should not be in use in current query level */
Assert(root->plan_params == NIL);
/*
* Generate the plan for the CTE query. Always plan for full
* retrieval --- we don't have enough info to predict otherwise.
*/
plan = subquery_planner(root->glob, subquery,
root,
cte->cterecursive, 0.0,
&subroot);
/*
* Since the current query level doesn't yet contain any RTEs, it
* should not be possible for the CTE to have requested parameters of
* this level.
*/
if (root->plan_params)
elog(ERROR, "unexpected outer reference in CTE query");
/*
* Make a SubPlan node for it. This is just enough unlike
* build_subplan that we can't share code.
*
* Note plan_id, plan_name, and cost fields are set further down.
*/
splan = makeNode(SubPlan);
splan->subLinkType = CTE_SUBLINK;
splan->testexpr = NULL;
splan->paramIds = NIL;
get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod,
&splan->firstColCollation);
splan->useHashTable = false;
splan->unknownEqFalse = false;
splan->setParam = NIL;
splan->parParam = NIL;
splan->args = NIL;
/*
* The node can't have any inputs (since it's an initplan), so the
* parParam and args lists remain empty. (It could contain references
* to earlier CTEs' output param IDs, but CTE outputs are not
* propagated via the args list.)
*/
/*
* Assign a param ID to represent the CTE's output. No ordinary
* "evaluation" of this param slot ever happens, but we use the param
* ID for setParam/chgParam signaling just as if the CTE plan were
* returning a simple scalar output. (Also, the executor abuses the
* ParamExecData slot for this param ID for communication among
* multiple CteScan nodes that might be scanning this CTE.)
*/
paramid = SS_assign_special_param(root);
splan->setParam = list_make1_int(paramid);
/*
* Add the subplan and its PlannerInfo to the global lists.
*/
root->glob->subplans = lappend(root->glob->subplans, plan);
root->glob->subroots = lappend(root->glob->subroots, subroot);
splan->plan_id = list_length(root->glob->subplans);
root->init_plans = lappend(root->init_plans, splan);
root->cte_plan_ids = lappend_int(root->cte_plan_ids, splan->plan_id);
/* Label the subplan for EXPLAIN purposes */
splan->plan_name = palloc(4 + strlen(cte->ctename) + 1);
sprintf(splan->plan_name, "CTE %s", cte->ctename);
/* Lastly, fill in the cost estimates for use later */
cost_subplan(root, splan, plan);
}
}
| Node* SS_process_sublinks | ( | PlannerInfo * | root, | |
| Node * | expr, | |||
| bool | isQual | |||
| ) |
Definition at line 1770 of file subselect.c.
References process_sublinks_context::isTopQual, process_sublinks_mutator(), and process_sublinks_context::root.
Referenced by build_subplan(), and preprocess_expression().
{
process_sublinks_context context;
context.root = root;
context.isTopQual = isQual;
return process_sublinks_mutator(expr, &context);
}
| Node* SS_replace_correlation_vars | ( | PlannerInfo * | root, | |
| Node * | expr | |||
| ) |
Definition at line 1730 of file subselect.c.
References replace_correlation_vars_mutator().
Referenced by preprocess_expression().
{
/* No setup needed for tree walk, so away we go */
return replace_correlation_vars_mutator(expr, root);
}
1.7.1