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subselect.h File Reference
#include "nodes/pathnodes.h"
#include "nodes/plannodes.h"
Include dependency graph for subselect.h:
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Functions

void SS_process_ctes (PlannerInfo *root)
 
JoinExprconvert_ANY_sublink_to_join (PlannerInfo *root, SubLink *sublink, Relids available_rels)
 
JoinExprconvert_EXISTS_sublink_to_join (PlannerInfo *root, SubLink *sublink, bool under_not, Relids available_rels)
 
NodeSS_replace_correlation_vars (PlannerInfo *root, Node *expr)
 
NodeSS_process_sublinks (PlannerInfo *root, Node *expr, bool isQual)
 
void SS_identify_outer_params (PlannerInfo *root)
 
void SS_charge_for_initplans (PlannerInfo *root, RelOptInfo *final_rel)
 
void SS_compute_initplan_cost (List *init_plans, Cost *initplan_cost_p, bool *unsafe_initplans_p)
 
void SS_attach_initplans (PlannerInfo *root, Plan *plan)
 
void SS_finalize_plan (PlannerInfo *root, Plan *plan)
 
ParamSS_make_initplan_output_param (PlannerInfo *root, Oid resulttype, int32 resulttypmod, Oid resultcollation)
 
void SS_make_initplan_from_plan (PlannerInfo *root, PlannerInfo *subroot, Plan *plan, Param *prm)
 

Function Documentation

◆ convert_ANY_sublink_to_join()

JoinExpr * convert_ANY_sublink_to_join ( PlannerInfo root,
SubLink sublink,
Relids  available_rels 
)

Definition at line 1251 of file subselect.c.

1253{
1254 JoinExpr *result;
1255 Query *parse = root->parse;
1256 Query *subselect = (Query *) sublink->subselect;
1257 Relids upper_varnos;
1258 int rtindex;
1259 ParseNamespaceItem *nsitem;
1260 RangeTblEntry *rte;
1261 RangeTblRef *rtr;
1262 List *subquery_vars;
1263 Node *quals;
1264 ParseState *pstate;
1265 Relids sub_ref_outer_relids;
1266 bool use_lateral;
1267
1268 Assert(sublink->subLinkType == ANY_SUBLINK);
1269
1270 /*
1271 * If the sub-select contains any Vars of the parent query, we treat it as
1272 * LATERAL. (Vars from higher levels don't matter here.)
1273 */
1274 sub_ref_outer_relids = pull_varnos_of_level(NULL, (Node *) subselect, 1);
1275 use_lateral = !bms_is_empty(sub_ref_outer_relids);
1276
1277 /*
1278 * Can't convert if the sub-select contains parent-level Vars of relations
1279 * not in available_rels.
1280 */
1281 if (!bms_is_subset(sub_ref_outer_relids, available_rels))
1282 return NULL;
1283
1284 /*
1285 * The test expression must contain some Vars of the parent query, else
1286 * it's not gonna be a join. (Note that it won't have Vars referring to
1287 * the subquery, rather Params.)
1288 */
1289 upper_varnos = pull_varnos(root, sublink->testexpr);
1290 if (bms_is_empty(upper_varnos))
1291 return NULL;
1292
1293 /*
1294 * However, it can't refer to anything outside available_rels.
1295 */
1296 if (!bms_is_subset(upper_varnos, available_rels))
1297 return NULL;
1298
1299 /*
1300 * The combining operators and left-hand expressions mustn't be volatile.
1301 */
1303 return NULL;
1304
1305 /* Create a dummy ParseState for addRangeTableEntryForSubquery */
1306 pstate = make_parsestate(NULL);
1307
1308 /*
1309 * Okay, pull up the sub-select into upper range table.
1310 *
1311 * We rely here on the assumption that the outer query has no references
1312 * to the inner (necessarily true, other than the Vars that we build
1313 * below). Therefore this is a lot easier than what pull_up_subqueries has
1314 * to go through.
1315 */
1316 nsitem = addRangeTableEntryForSubquery(pstate,
1317 subselect,
1318 makeAlias("ANY_subquery", NIL),
1319 use_lateral,
1320 false);
1321 rte = nsitem->p_rte;
1322 parse->rtable = lappend(parse->rtable, rte);
1323 rtindex = list_length(parse->rtable);
1324
1325 /*
1326 * Form a RangeTblRef for the pulled-up sub-select.
1327 */
1328 rtr = makeNode(RangeTblRef);
1329 rtr->rtindex = rtindex;
1330
1331 /*
1332 * Build a list of Vars representing the subselect outputs.
1333 */
1334 subquery_vars = generate_subquery_vars(root,
1335 subselect->targetList,
1336 rtindex);
1337
1338 /*
1339 * Build the new join's qual expression, replacing Params with these Vars.
1340 */
1341 quals = convert_testexpr(root, sublink->testexpr, subquery_vars);
1342
1343 /*
1344 * And finally, build the JoinExpr node.
1345 */
1346 result = makeNode(JoinExpr);
1347 result->jointype = JOIN_SEMI;
1348 result->isNatural = false;
1349 result->larg = NULL; /* caller must fill this in */
1350 result->rarg = (Node *) rtr;
1351 result->usingClause = NIL;
1352 result->join_using_alias = NULL;
1353 result->quals = quals;
1354 result->alias = NULL;
1355 result->rtindex = 0; /* we don't need an RTE for it */
1356
1357 return result;
1358}
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:412
#define bms_is_empty(a)
Definition: bitmapset.h:118
#define Assert(condition)
Definition: c.h:812
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:537
List * lappend(List *list, void *datum)
Definition: list.c:339
Alias * makeAlias(const char *aliasname, List *colnames)
Definition: makefuncs.c:389
#define makeNode(_type_)
Definition: nodes.h:155
@ JOIN_SEMI
Definition: nodes.h:307
ParseState * make_parsestate(ParseState *parentParseState)
Definition: parse_node.c:39
ParseNamespaceItem * addRangeTableEntryForSubquery(ParseState *pstate, Query *subquery, Alias *alias, bool lateral, bool inFromCl)
static int list_length(const List *l)
Definition: pg_list.h:152
#define NIL
Definition: pg_list.h:68
@ ANY_SUBLINK
Definition: primnodes.h:999
tree ctl root
Definition: radixtree.h:1857
static struct subre * parse(struct vars *v, int stopper, int type, struct state *init, struct state *final)
Definition: regcomp.c:717
Node * quals
Definition: primnodes.h:2289
JoinType jointype
Definition: primnodes.h:2280
int rtindex
Definition: primnodes.h:2293
Node * larg
Definition: primnodes.h:2282
bool isNatural
Definition: primnodes.h:2281
Node * rarg
Definition: primnodes.h:2283
Definition: pg_list.h:54
Definition: nodes.h:129
List * targetList
Definition: parsenodes.h:193
static List * generate_subquery_vars(PlannerInfo *root, List *tlist, Index varno)
Definition: subselect.c:613
static Node * convert_testexpr(PlannerInfo *root, Node *testexpr, List *subst_nodes)
Definition: subselect.c:642
Relids pull_varnos_of_level(PlannerInfo *root, Node *node, int levelsup)
Definition: var.c:139
Relids pull_varnos(PlannerInfo *root, Node *node)
Definition: var.c:113

References addRangeTableEntryForSubquery(), ANY_SUBLINK, Assert, bms_is_empty, bms_is_subset(), contain_volatile_functions(), convert_testexpr(), generate_subquery_vars(), JoinExpr::isNatural, JOIN_SEMI, JoinExpr::jointype, lappend(), JoinExpr::larg, list_length(), make_parsestate(), makeAlias(), makeNode, NIL, parse(), pull_varnos(), pull_varnos_of_level(), JoinExpr::quals, JoinExpr::rarg, root, JoinExpr::rtindex, SubLink::subLinkType, SubLink::subselect, Query::targetList, and SubLink::testexpr.

Referenced by pull_up_sublinks_qual_recurse().

◆ convert_EXISTS_sublink_to_join()

JoinExpr * convert_EXISTS_sublink_to_join ( PlannerInfo root,
SubLink sublink,
bool  under_not,
Relids  available_rels 
)

Definition at line 1368 of file subselect.c.

1370{
1371 JoinExpr *result;
1372 Query *parse = root->parse;
1373 Query *subselect = (Query *) sublink->subselect;
1374 Node *whereClause;
1375 int rtoffset;
1376 int varno;
1377 Relids clause_varnos;
1378 Relids upper_varnos;
1379
1380 Assert(sublink->subLinkType == EXISTS_SUBLINK);
1381
1382 /*
1383 * Can't flatten if it contains WITH. (We could arrange to pull up the
1384 * WITH into the parent query's cteList, but that risks changing the
1385 * semantics, since a WITH ought to be executed once per associated query
1386 * call.) Note that convert_ANY_sublink_to_join doesn't have to reject
1387 * this case, since it just produces a subquery RTE that doesn't have to
1388 * get flattened into the parent query.
1389 */
1390 if (subselect->cteList)
1391 return NULL;
1392
1393 /*
1394 * Copy the subquery so we can modify it safely (see comments in
1395 * make_subplan).
1396 */
1397 subselect = copyObject(subselect);
1398
1399 /*
1400 * See if the subquery can be simplified based on the knowledge that it's
1401 * being used in EXISTS(). If we aren't able to get rid of its
1402 * targetlist, we have to fail, because the pullup operation leaves us
1403 * with noplace to evaluate the targetlist.
1404 */
1405 if (!simplify_EXISTS_query(root, subselect))
1406 return NULL;
1407
1408 /*
1409 * Separate out the WHERE clause. (We could theoretically also remove
1410 * top-level plain JOIN/ON clauses, but it's probably not worth the
1411 * trouble.)
1412 */
1413 whereClause = subselect->jointree->quals;
1414 subselect->jointree->quals = NULL;
1415
1416 /*
1417 * The rest of the sub-select must not refer to any Vars of the parent
1418 * query. (Vars of higher levels should be okay, though.)
1419 */
1420 if (contain_vars_of_level((Node *) subselect, 1))
1421 return NULL;
1422
1423 /*
1424 * On the other hand, the WHERE clause must contain some Vars of the
1425 * parent query, else it's not gonna be a join.
1426 */
1427 if (!contain_vars_of_level(whereClause, 1))
1428 return NULL;
1429
1430 /*
1431 * We don't risk optimizing if the WHERE clause is volatile, either.
1432 */
1433 if (contain_volatile_functions(whereClause))
1434 return NULL;
1435
1436 /*
1437 * The subquery must have a nonempty jointree, but we can make it so.
1438 */
1439 replace_empty_jointree(subselect);
1440
1441 /*
1442 * Prepare to pull up the sub-select into top range table.
1443 *
1444 * We rely here on the assumption that the outer query has no references
1445 * to the inner (necessarily true). Therefore this is a lot easier than
1446 * what pull_up_subqueries has to go through.
1447 *
1448 * In fact, it's even easier than what convert_ANY_sublink_to_join has to
1449 * do. The machinations of simplify_EXISTS_query ensured that there is
1450 * nothing interesting in the subquery except an rtable and jointree, and
1451 * even the jointree FromExpr no longer has quals. So we can just append
1452 * the rtable to our own and use the FromExpr in our jointree. But first,
1453 * adjust all level-zero varnos in the subquery to account for the rtable
1454 * merger.
1455 */
1456 rtoffset = list_length(parse->rtable);
1457 OffsetVarNodes((Node *) subselect, rtoffset, 0);
1458 OffsetVarNodes(whereClause, rtoffset, 0);
1459
1460 /*
1461 * Upper-level vars in subquery will now be one level closer to their
1462 * parent than before; in particular, anything that had been level 1
1463 * becomes level zero.
1464 */
1465 IncrementVarSublevelsUp((Node *) subselect, -1, 1);
1466 IncrementVarSublevelsUp(whereClause, -1, 1);
1467
1468 /*
1469 * Now that the WHERE clause is adjusted to match the parent query
1470 * environment, we can easily identify all the level-zero rels it uses.
1471 * The ones <= rtoffset belong to the upper query; the ones > rtoffset do
1472 * not.
1473 */
1474 clause_varnos = pull_varnos(root, whereClause);
1475 upper_varnos = NULL;
1476 varno = -1;
1477 while ((varno = bms_next_member(clause_varnos, varno)) >= 0)
1478 {
1479 if (varno <= rtoffset)
1480 upper_varnos = bms_add_member(upper_varnos, varno);
1481 }
1482 bms_free(clause_varnos);
1483 Assert(!bms_is_empty(upper_varnos));
1484
1485 /*
1486 * Now that we've got the set of upper-level varnos, we can make the last
1487 * check: only available_rels can be referenced.
1488 */
1489 if (!bms_is_subset(upper_varnos, available_rels))
1490 return NULL;
1491
1492 /*
1493 * Now we can attach the modified subquery rtable to the parent. This also
1494 * adds subquery's RTEPermissionInfos into the upper query.
1495 */
1496 CombineRangeTables(&parse->rtable, &parse->rteperminfos,
1497 subselect->rtable, subselect->rteperminfos);
1498
1499 /*
1500 * And finally, build the JoinExpr node.
1501 */
1502 result = makeNode(JoinExpr);
1503 result->jointype = under_not ? JOIN_ANTI : JOIN_SEMI;
1504 result->isNatural = false;
1505 result->larg = NULL; /* caller must fill this in */
1506 /* flatten out the FromExpr node if it's useless */
1507 if (list_length(subselect->jointree->fromlist) == 1)
1508 result->rarg = (Node *) linitial(subselect->jointree->fromlist);
1509 else
1510 result->rarg = (Node *) subselect->jointree;
1511 result->usingClause = NIL;
1512 result->join_using_alias = NULL;
1513 result->quals = whereClause;
1514 result->alias = NULL;
1515 result->rtindex = 0; /* we don't need an RTE for it */
1516
1517 return result;
1518}
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1306
void bms_free(Bitmapset *a)
Definition: bitmapset.c:239
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:815
#define copyObject(obj)
Definition: nodes.h:224
@ JOIN_ANTI
Definition: nodes.h:308
#define linitial(l)
Definition: pg_list.h:178
void replace_empty_jointree(Query *parse)
Definition: prepjointree.c:395
@ EXISTS_SUBLINK
Definition: primnodes.h:997
void OffsetVarNodes(Node *node, int offset, int sublevels_up)
Definition: rewriteManip.c:476
void CombineRangeTables(List **dst_rtable, List **dst_perminfos, List *src_rtable, List *src_perminfos)
Definition: rewriteManip.c:347
void IncrementVarSublevelsUp(Node *node, int delta_sublevels_up, int min_sublevels_up)
Definition: rewriteManip.c:841
Node * quals
Definition: primnodes.h:2309
FromExpr * jointree
Definition: parsenodes.h:177
List * cteList
Definition: parsenodes.h:168
static bool simplify_EXISTS_query(PlannerInfo *root, Query *query)
Definition: subselect.c:1537
bool contain_vars_of_level(Node *node, int levelsup)
Definition: var.c:443

References Assert, bms_add_member(), bms_free(), bms_is_empty, bms_is_subset(), bms_next_member(), CombineRangeTables(), contain_vars_of_level(), contain_volatile_functions(), copyObject, Query::cteList, EXISTS_SUBLINK, FromExpr::fromlist, IncrementVarSublevelsUp(), JoinExpr::isNatural, JOIN_ANTI, JOIN_SEMI, Query::jointree, JoinExpr::jointype, JoinExpr::larg, linitial, list_length(), makeNode, NIL, OffsetVarNodes(), parse(), pull_varnos(), JoinExpr::quals, FromExpr::quals, JoinExpr::rarg, replace_empty_jointree(), root, Query::rtable, JoinExpr::rtindex, simplify_EXISTS_query(), SubLink::subLinkType, and SubLink::subselect.

Referenced by pull_up_sublinks_qual_recurse().

◆ SS_attach_initplans()

void SS_attach_initplans ( PlannerInfo root,
Plan plan 
)

Definition at line 2258 of file subselect.c.

2259{
2260 plan->initPlan = root->init_plans;
2261}
#define plan(x)
Definition: pg_regress.c:161

References plan, and root.

Referenced by create_plan().

◆ SS_charge_for_initplans()

void SS_charge_for_initplans ( PlannerInfo root,
RelOptInfo final_rel 
)

Definition at line 2153 of file subselect.c.

2154{
2155 Cost initplan_cost;
2156 bool unsafe_initplans;
2157 ListCell *lc;
2158
2159 /* Nothing to do if no initPlans */
2160 if (root->init_plans == NIL)
2161 return;
2162
2163 /*
2164 * Compute the cost increment just once, since it will be the same for all
2165 * Paths. Also check for parallel-unsafe initPlans.
2166 */
2167 SS_compute_initplan_cost(root->init_plans,
2168 &initplan_cost, &unsafe_initplans);
2169
2170 /*
2171 * Now adjust the costs and parallel_safe flags.
2172 */
2173 foreach(lc, final_rel->pathlist)
2174 {
2175 Path *path = (Path *) lfirst(lc);
2176
2177 path->startup_cost += initplan_cost;
2178 path->total_cost += initplan_cost;
2179 if (unsafe_initplans)
2180 path->parallel_safe = false;
2181 }
2182
2183 /*
2184 * Adjust partial paths' costs too, or forget them entirely if we must
2185 * consider the rel parallel-unsafe.
2186 */
2187 if (unsafe_initplans)
2188 {
2189 final_rel->partial_pathlist = NIL;
2190 final_rel->consider_parallel = false;
2191 }
2192 else
2193 {
2194 foreach(lc, final_rel->partial_pathlist)
2195 {
2196 Path *path = (Path *) lfirst(lc);
2197
2198 path->startup_cost += initplan_cost;
2199 path->total_cost += initplan_cost;
2200 }
2201 }
2202
2203 /* We needn't do set_cheapest() here, caller will do it */
2204}
double Cost
Definition: nodes.h:251
#define lfirst(lc)
Definition: pg_list.h:172
Cost startup_cost
Definition: pathnodes.h:1673
Cost total_cost
Definition: pathnodes.h:1674
bool parallel_safe
Definition: pathnodes.h:1666
bool consider_parallel
Definition: pathnodes.h:887
List * pathlist
Definition: pathnodes.h:898
List * partial_pathlist
Definition: pathnodes.h:900
void SS_compute_initplan_cost(List *init_plans, Cost *initplan_cost_p, bool *unsafe_initplans_p)
Definition: subselect.c:2217

References RelOptInfo::consider_parallel, lfirst, NIL, Path::parallel_safe, RelOptInfo::partial_pathlist, RelOptInfo::pathlist, root, SS_compute_initplan_cost(), Path::startup_cost, and Path::total_cost.

Referenced by build_minmax_path(), and subquery_planner().

◆ SS_compute_initplan_cost()

void SS_compute_initplan_cost ( List init_plans,
Cost initplan_cost_p,
bool *  unsafe_initplans_p 
)

Definition at line 2217 of file subselect.c.

2220{
2221 Cost initplan_cost;
2222 bool unsafe_initplans;
2223 ListCell *lc;
2224
2225 /*
2226 * We assume each initPlan gets run once during top plan startup. This is
2227 * a conservative overestimate, since in fact an initPlan might be
2228 * executed later than plan startup, or even not at all.
2229 */
2230 initplan_cost = 0;
2231 unsafe_initplans = false;
2232 foreach(lc, init_plans)
2233 {
2234 SubPlan *initsubplan = lfirst_node(SubPlan, lc);
2235
2236 initplan_cost += initsubplan->startup_cost + initsubplan->per_call_cost;
2237 if (!initsubplan->parallel_safe)
2238 unsafe_initplans = true;
2239 }
2240 *initplan_cost_p = initplan_cost;
2241 *unsafe_initplans_p = unsafe_initplans;
2242}
#define lfirst_node(type, lc)
Definition: pg_list.h:176
bool parallel_safe
Definition: primnodes.h:1084
Cost startup_cost
Definition: primnodes.h:1093
Cost per_call_cost
Definition: primnodes.h:1094

References lfirst_node, SubPlan::parallel_safe, SubPlan::per_call_cost, and SubPlan::startup_cost.

Referenced by clean_up_removed_plan_level(), materialize_finished_plan(), SS_charge_for_initplans(), and standard_planner().

◆ SS_finalize_plan()

void SS_finalize_plan ( PlannerInfo root,
Plan plan 
)

Definition at line 2273 of file subselect.c.

2274{
2275 /* No setup needed, just recurse through plan tree. */
2276 (void) finalize_plan(root, plan, -1, root->outer_params, NULL);
2277}
static Bitmapset * finalize_plan(PlannerInfo *root, Plan *plan, int gather_param, Bitmapset *valid_params, Bitmapset *scan_params)
Definition: subselect.c:2311

References finalize_plan(), plan, and root.

Referenced by standard_planner().

◆ SS_identify_outer_params()

void SS_identify_outer_params ( PlannerInfo root)

Definition at line 2091 of file subselect.c.

2092{
2093 Bitmapset *outer_params;
2094 PlannerInfo *proot;
2095 ListCell *l;
2096
2097 /*
2098 * If no parameters have been assigned anywhere in the tree, we certainly
2099 * don't need to do anything here.
2100 */
2101 if (root->glob->paramExecTypes == NIL)
2102 return;
2103
2104 /*
2105 * Scan all query levels above this one to see which parameters are due to
2106 * be available from them, either because lower query levels have
2107 * requested them (via plan_params) or because they will be available from
2108 * initPlans of those levels.
2109 */
2110 outer_params = NULL;
2111 for (proot = root->parent_root; proot != NULL; proot = proot->parent_root)
2112 {
2113 /* Include ordinary Var/PHV/Aggref/GroupingFunc params */
2114 foreach(l, proot->plan_params)
2115 {
2117
2118 outer_params = bms_add_member(outer_params, pitem->paramId);
2119 }
2120 /* Include any outputs of outer-level initPlans */
2121 foreach(l, proot->init_plans)
2122 {
2123 SubPlan *initsubplan = (SubPlan *) lfirst(l);
2124 ListCell *l2;
2125
2126 foreach(l2, initsubplan->setParam)
2127 {
2128 outer_params = bms_add_member(outer_params, lfirst_int(l2));
2129 }
2130 }
2131 /* Include worktable ID, if a recursive query is being planned */
2132 if (proot->wt_param_id >= 0)
2133 outer_params = bms_add_member(outer_params, proot->wt_param_id);
2134 }
2135 root->outer_params = outer_params;
2136}
#define lfirst_int(lc)
Definition: pg_list.h:173
List * init_plans
Definition: pathnodes.h:299
int wt_param_id
Definition: pathnodes.h:536
List * plan_params
Definition: pathnodes.h:220
List * setParam
Definition: primnodes.h:1088

References bms_add_member(), PlannerInfo::init_plans, lfirst, lfirst_int, NIL, PlannerParamItem::paramId, PlannerInfo::plan_params, root, SubPlan::setParam, and PlannerInfo::wt_param_id.

Referenced by build_minmax_path(), and subquery_planner().

◆ SS_make_initplan_from_plan()

void SS_make_initplan_from_plan ( PlannerInfo root,
PlannerInfo subroot,
Plan plan,
Param prm 
)

Definition at line 3034 of file subselect.c.

3037{
3038 SubPlan *node;
3039
3040 /*
3041 * Add the subplan and its PlannerInfo, as well as a dummy path entry, to
3042 * the global lists. Ideally we'd save a real path, but right now our
3043 * sole caller doesn't build a path that exactly matches the plan. Since
3044 * we're not currently going to need the path for an initplan, it's not
3045 * worth requiring construction of such a path.
3046 */
3047 root->glob->subplans = lappend(root->glob->subplans, plan);
3048 root->glob->subpaths = lappend(root->glob->subpaths, NULL);
3049 root->glob->subroots = lappend(root->glob->subroots, subroot);
3050
3051 /*
3052 * Create a SubPlan node and add it to the outer list of InitPlans. Note
3053 * it has to appear after any other InitPlans it might depend on (see
3054 * comments in ExecReScan).
3055 */
3056 node = makeNode(SubPlan);
3057 node->subLinkType = EXPR_SUBLINK;
3058 node->plan_id = list_length(root->glob->subplans);
3059 node->plan_name = psprintf("InitPlan %d", node->plan_id);
3061 &node->firstColCollation);
3062 node->parallel_safe = plan->parallel_safe;
3063 node->setParam = list_make1_int(prm->paramid);
3064
3065 root->init_plans = lappend(root->init_plans, node);
3066
3067 /*
3068 * The node can't have any inputs (since it's an initplan), so the
3069 * parParam and args lists remain empty.
3070 */
3071
3072 /* Set costs of SubPlan using info from the plan tree */
3073 cost_subplan(subroot, node, plan);
3074}
void cost_subplan(PlannerInfo *root, SubPlan *subplan, Plan *plan)
Definition: costsize.c:4524
#define list_make1_int(x1)
Definition: pg_list.h:227
@ EXPR_SUBLINK
Definition: primnodes.h:1001
char * psprintf(const char *fmt,...)
Definition: psprintf.c:43
int paramid
Definition: primnodes.h:377
int plan_id
Definition: primnodes.h:1070
char * plan_name
Definition: primnodes.h:1072
int32 firstColTypmod
Definition: primnodes.h:1075
Oid firstColCollation
Definition: primnodes.h:1076
SubLinkType subLinkType
Definition: primnodes.h:1065
Oid firstColType
Definition: primnodes.h:1074
static void get_first_col_type(Plan *plan, Oid *coltype, int32 *coltypmod, Oid *colcollation)
Definition: subselect.c:118

References cost_subplan(), EXPR_SUBLINK, SubPlan::firstColCollation, SubPlan::firstColType, SubPlan::firstColTypmod, get_first_col_type(), lappend(), list_length(), list_make1_int, makeNode, SubPlan::parallel_safe, Param::paramid, plan, SubPlan::plan_id, SubPlan::plan_name, psprintf(), root, SubPlan::setParam, and SubPlan::subLinkType.

Referenced by create_minmaxagg_plan().

◆ SS_make_initplan_output_param()

Param * SS_make_initplan_output_param ( PlannerInfo root,
Oid  resulttype,
int32  resulttypmod,
Oid  resultcollation 
)

Definition at line 3018 of file subselect.c.

3021{
3022 return generate_new_exec_param(root, resulttype,
3023 resulttypmod, resultcollation);
3024}
Param * generate_new_exec_param(PlannerInfo *root, Oid paramtype, int32 paramtypmod, Oid paramcollation)
Definition: paramassign.c:637

References generate_new_exec_param(), and root.

Referenced by preprocess_minmax_aggregates().

◆ SS_process_ctes()

void SS_process_ctes ( PlannerInfo root)

Definition at line 878 of file subselect.c.

879{
880 ListCell *lc;
881
882 Assert(root->cte_plan_ids == NIL);
883
884 foreach(lc, root->parse->cteList)
885 {
887 CmdType cmdType = ((Query *) cte->ctequery)->commandType;
888 Query *subquery;
889 PlannerInfo *subroot;
890 RelOptInfo *final_rel;
891 Path *best_path;
892 Plan *plan;
893 SubPlan *splan;
894 int paramid;
895
896 /*
897 * Ignore SELECT CTEs that are not actually referenced anywhere.
898 */
899 if (cte->cterefcount == 0 && cmdType == CMD_SELECT)
900 {
901 /* Make a dummy entry in cte_plan_ids */
902 root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
903 continue;
904 }
905
906 /*
907 * Consider inlining the CTE (creating RTE_SUBQUERY RTE(s)) instead of
908 * implementing it as a separately-planned CTE.
909 *
910 * We cannot inline if any of these conditions hold:
911 *
912 * 1. The user said not to (the CTEMaterializeAlways option).
913 *
914 * 2. The CTE is recursive.
915 *
916 * 3. The CTE has side-effects; this includes either not being a plain
917 * SELECT, or containing volatile functions. Inlining might change
918 * the side-effects, which would be bad.
919 *
920 * 4. The CTE is multiply-referenced and contains a self-reference to
921 * a recursive CTE outside itself. Inlining would result in multiple
922 * recursive self-references, which we don't support.
923 *
924 * Otherwise, we have an option whether to inline or not. That should
925 * always be a win if there's just a single reference, but if the CTE
926 * is multiply-referenced then it's unclear: inlining adds duplicate
927 * computations, but the ability to absorb restrictions from the outer
928 * query level could outweigh that. We do not have nearly enough
929 * information at this point to tell whether that's true, so we let
930 * the user express a preference. Our default behavior is to inline
931 * only singly-referenced CTEs, but a CTE marked CTEMaterializeNever
932 * will be inlined even if multiply referenced.
933 *
934 * Note: we check for volatile functions last, because that's more
935 * expensive than the other tests needed.
936 */
939 cte->cterefcount == 1)) &&
940 !cte->cterecursive &&
941 cmdType == CMD_SELECT &&
942 !contain_dml(cte->ctequery) &&
943 (cte->cterefcount <= 1 ||
946 {
947 inline_cte(root, cte);
948 /* Make a dummy entry in cte_plan_ids */
949 root->cte_plan_ids = lappend_int(root->cte_plan_ids, -1);
950 continue;
951 }
952
953 /*
954 * Copy the source Query node. Probably not necessary, but let's keep
955 * this similar to make_subplan.
956 */
957 subquery = (Query *) copyObject(cte->ctequery);
958
959 /* plan_params should not be in use in current query level */
960 Assert(root->plan_params == NIL);
961
962 /*
963 * Generate Paths for the CTE query. Always plan for full retrieval
964 * --- we don't have enough info to predict otherwise.
965 */
966 subroot = subquery_planner(root->glob, subquery, root,
967 cte->cterecursive, 0.0, NULL);
968
969 /*
970 * Since the current query level doesn't yet contain any RTEs, it
971 * should not be possible for the CTE to have requested parameters of
972 * this level.
973 */
974 if (root->plan_params)
975 elog(ERROR, "unexpected outer reference in CTE query");
976
977 /*
978 * Select best Path and turn it into a Plan. At least for now, there
979 * seems no reason to postpone doing that.
980 */
981 final_rel = fetch_upper_rel(subroot, UPPERREL_FINAL, NULL);
982 best_path = final_rel->cheapest_total_path;
983
984 plan = create_plan(subroot, best_path);
985
986 /*
987 * Make a SubPlan node for it. This is just enough unlike
988 * build_subplan that we can't share code.
989 *
990 * Note plan_id, plan_name, and cost fields are set further down.
991 */
993 splan->subLinkType = CTE_SUBLINK;
994 splan->testexpr = NULL;
995 splan->paramIds = NIL;
996 get_first_col_type(plan, &splan->firstColType, &splan->firstColTypmod,
997 &splan->firstColCollation);
998 splan->useHashTable = false;
999 splan->unknownEqFalse = false;
1000
1001 /*
1002 * CTE scans are not considered for parallelism (cf
1003 * set_rel_consider_parallel).
1004 */
1005 splan->parallel_safe = false;
1006 splan->setParam = NIL;
1007 splan->parParam = NIL;
1008 splan->args = NIL;
1009
1010 /*
1011 * The node can't have any inputs (since it's an initplan), so the
1012 * parParam and args lists remain empty. (It could contain references
1013 * to earlier CTEs' output param IDs, but CTE outputs are not
1014 * propagated via the args list.)
1015 */
1016
1017 /*
1018 * Assign a param ID to represent the CTE's output. No ordinary
1019 * "evaluation" of this param slot ever happens, but we use the param
1020 * ID for setParam/chgParam signaling just as if the CTE plan were
1021 * returning a simple scalar output. (Also, the executor abuses the
1022 * ParamExecData slot for this param ID for communication among
1023 * multiple CteScan nodes that might be scanning this CTE.)
1024 */
1026 splan->setParam = list_make1_int(paramid);
1027
1028 /*
1029 * Add the subplan, its path, and its PlannerInfo to the global lists.
1030 */
1031 root->glob->subplans = lappend(root->glob->subplans, plan);
1032 root->glob->subpaths = lappend(root->glob->subpaths, best_path);
1033 root->glob->subroots = lappend(root->glob->subroots, subroot);
1034 splan->plan_id = list_length(root->glob->subplans);
1035
1036 root->init_plans = lappend(root->init_plans, splan);
1037
1038 root->cte_plan_ids = lappend_int(root->cte_plan_ids, splan->plan_id);
1039
1040 /* Label the subplan for EXPLAIN purposes */
1041 splan->plan_name = psprintf("CTE %s", cte->ctename);
1042
1043 /* Lastly, fill in the cost estimates for use later */
1045 }
1046}
Plan * create_plan(PlannerInfo *root, Path *best_path)
Definition: createplan.c:340
#define ERROR
Definition: elog.h:39
#define elog(elevel,...)
Definition: elog.h:225
List * lappend_int(List *list, int datum)
Definition: list.c:357
CmdType
Definition: nodes.h:263
@ CMD_SELECT
Definition: nodes.h:265
int assign_special_exec_param(PlannerInfo *root)
Definition: paramassign.c:664
@ CTEMaterializeNever
Definition: parsenodes.h:1640
@ CTEMaterializeDefault
Definition: parsenodes.h:1638
@ UPPERREL_FINAL
Definition: pathnodes.h:79
PlannerInfo * subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root, bool hasRecursion, double tuple_fraction, SetOperationStmt *setops)
Definition: planner.c:638
@ CTE_SUBLINK
Definition: primnodes.h:1004
static SPIPlanPtr splan
Definition: regress.c:267
RelOptInfo * fetch_upper_rel(PlannerInfo *root, UpperRelationKind kind, Relids relids)
Definition: relnode.c:1458
CTEMaterialize ctematerialized
Definition: parsenodes.h:1679
struct Path * cheapest_total_path
Definition: pathnodes.h:902
static bool contain_outer_selfref(Node *node)
Definition: subselect.c:1081
static bool contain_dml(Node *node)
Definition: subselect.c:1054
static void inline_cte(PlannerInfo *root, CommonTableExpr *cte)
Definition: subselect.c:1135

References Assert, assign_special_exec_param(), RelOptInfo::cheapest_total_path, CMD_SELECT, contain_dml(), contain_outer_selfref(), contain_volatile_functions(), copyObject, cost_subplan(), create_plan(), CTE_SUBLINK, CommonTableExpr::ctematerialized, CTEMaterializeDefault, CTEMaterializeNever, CommonTableExpr::ctename, CommonTableExpr::ctequery, elog, ERROR, fetch_upper_rel(), get_first_col_type(), inline_cte(), lappend(), lappend_int(), lfirst, list_length(), list_make1_int, makeNode, NIL, plan, psprintf(), root, splan, subquery_planner(), and UPPERREL_FINAL.

Referenced by subquery_planner().

◆ SS_process_sublinks()

Node * SS_process_sublinks ( PlannerInfo root,
Node expr,
bool  isQual 
)

Definition at line 1938 of file subselect.c.

1939{
1941
1942 context.root = root;
1943 context.isTopQual = isQual;
1944 return process_sublinks_mutator(expr, &context);
1945}
static Node * process_sublinks_mutator(Node *node, process_sublinks_context *context)
Definition: subselect.c:1948

References process_sublinks_context::isTopQual, process_sublinks_mutator(), process_sublinks_context::root, and root.

Referenced by build_subplan(), and preprocess_expression().

◆ SS_replace_correlation_vars()

Node * SS_replace_correlation_vars ( PlannerInfo root,
Node expr 
)

Definition at line 1889 of file subselect.c.

1890{
1891 /* No setup needed for tree walk, so away we go */
1893}
static Node * replace_correlation_vars_mutator(Node *node, PlannerInfo *root)
Definition: subselect.c:1896

References replace_correlation_vars_mutator(), and root.

Referenced by preprocess_expression().