PostgreSQL Source Code  git master
allpaths.c File Reference
#include "postgres.h"
#include <limits.h>
#include <math.h>
#include "access/sysattr.h"
#include "access/tsmapi.h"
#include "catalog/pg_class.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/appendinfo.h"
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/geqo.h"
#include "optimizer/inherit.h"
#include "optimizer/optimizer.h"
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/plancat.h"
#include "optimizer/planner.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/tlist.h"
#include "parser/parse_clause.h"
#include "parser/parsetree.h"
#include "partitioning/partbounds.h"
#include "partitioning/partprune.h"
#include "rewrite/rewriteManip.h"
#include "utils/lsyscache.h"
Include dependency graph for allpaths.c:

Go to the source code of this file.

Data Structures

struct  pushdown_safety_info
 

Typedefs

typedef struct pushdown_safety_info pushdown_safety_info
 

Functions

static void set_base_rel_consider_startup (PlannerInfo *root)
 
static void set_base_rel_sizes (PlannerInfo *root)
 
static void set_base_rel_pathlists (PlannerInfo *root)
 
static void set_rel_size (PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
 
static void set_rel_pathlist (PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
 
static void set_plain_rel_size (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void create_plain_partial_paths (PlannerInfo *root, RelOptInfo *rel)
 
static void set_rel_consider_parallel (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_plain_rel_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_tablesample_rel_size (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_tablesample_rel_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_foreign_size (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_foreign_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_append_rel_size (PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
 
static void set_append_rel_pathlist (PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
 
static void generate_orderedappend_paths (PlannerInfo *root, RelOptInfo *rel, List *live_childrels, List *all_child_pathkeys, List *partitioned_rels)
 
static Pathget_cheapest_parameterized_child_path (PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
 
static void accumulate_append_subpath (Path *path, List **subpaths, List **special_subpaths)
 
static Pathget_singleton_append_subpath (Path *path)
 
static void set_dummy_rel_pathlist (RelOptInfo *rel)
 
static void set_subquery_pathlist (PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
 
static void set_function_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_values_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_tablefunc_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_cte_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_namedtuplestore_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_result_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static void set_worktable_pathlist (PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
 
static RelOptInfomake_rel_from_joinlist (PlannerInfo *root, List *joinlist)
 
static bool subquery_is_pushdown_safe (Query *subquery, Query *topquery, pushdown_safety_info *safetyInfo)
 
static bool recurse_pushdown_safe (Node *setOp, Query *topquery, pushdown_safety_info *safetyInfo)
 
static void check_output_expressions (Query *subquery, pushdown_safety_info *safetyInfo)
 
static void compare_tlist_datatypes (List *tlist, List *colTypes, pushdown_safety_info *safetyInfo)
 
static bool targetIsInAllPartitionLists (TargetEntry *tle, Query *query)
 
static bool qual_is_pushdown_safe (Query *subquery, Index rti, Node *qual, pushdown_safety_info *safetyInfo)
 
static void subquery_push_qual (Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
 
static void recurse_push_qual (Node *setOp, Query *topquery, RangeTblEntry *rte, Index rti, Node *qual)
 
static void remove_unused_subquery_outputs (Query *subquery, RelOptInfo *rel)
 
RelOptInfomake_one_rel (PlannerInfo *root, List *joinlist)
 
void add_paths_to_append_rel (PlannerInfo *root, RelOptInfo *rel, List *live_childrels)
 
static bool has_multiple_baserels (PlannerInfo *root)
 
void generate_gather_paths (PlannerInfo *root, RelOptInfo *rel, bool override_rows)
 
static Listget_useful_pathkeys_for_relation (PlannerInfo *root, RelOptInfo *rel)
 
void generate_useful_gather_paths (PlannerInfo *root, RelOptInfo *rel, bool override_rows)
 
RelOptInfostandard_join_search (PlannerInfo *root, int levels_needed, List *initial_rels)
 
void create_partial_bitmap_paths (PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual)
 
int compute_parallel_worker (RelOptInfo *rel, double heap_pages, double index_pages, int max_workers)
 
void generate_partitionwise_join_paths (PlannerInfo *root, RelOptInfo *rel)
 

Variables

bool enable_geqo = false
 
int geqo_threshold
 
int min_parallel_table_scan_size
 
int min_parallel_index_scan_size
 
set_rel_pathlist_hook_type set_rel_pathlist_hook = NULL
 
join_search_hook_type join_search_hook = NULL
 

Typedef Documentation

◆ pushdown_safety_info

Function Documentation

◆ accumulate_append_subpath()

static void accumulate_append_subpath ( Path path,
List **  subpaths,
List **  special_subpaths 
)
static

Definition at line 2045 of file allpaths.c.

References AppendPath::first_partial_path, IsA, lappend(), list_concat(), list_copy(), list_copy_tail(), list_truncate(), Path::parallel_aware, AppendPath::path, AppendPath::subpaths, and MergeAppendPath::subpaths.

Referenced by add_paths_to_append_rel(), and generate_orderedappend_paths().

2046 {
2047  if (IsA(path, AppendPath))
2048  {
2049  AppendPath *apath = (AppendPath *) path;
2050 
2051  if (!apath->path.parallel_aware || apath->first_partial_path == 0)
2052  {
2053  *subpaths = list_concat(*subpaths, apath->subpaths);
2054  return;
2055  }
2056  else if (special_subpaths != NULL)
2057  {
2058  List *new_special_subpaths;
2059 
2060  /* Split Parallel Append into partial and non-partial subpaths */
2061  *subpaths = list_concat(*subpaths,
2062  list_copy_tail(apath->subpaths,
2063  apath->first_partial_path));
2064  new_special_subpaths =
2066  apath->first_partial_path);
2067  *special_subpaths = list_concat(*special_subpaths,
2068  new_special_subpaths);
2069  return;
2070  }
2071  }
2072  else if (IsA(path, MergeAppendPath))
2073  {
2074  MergeAppendPath *mpath = (MergeAppendPath *) path;
2075 
2076  *subpaths = list_concat(*subpaths, mpath->subpaths);
2077  return;
2078  }
2079 
2080  *subpaths = lappend(*subpaths, path);
2081 }
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
List * list_truncate(List *list, int new_size)
Definition: list.c:585
List * list_copy(const List *oldlist)
Definition: list.c:1403
List * list_concat(List *list1, const List *list2)
Definition: list.c:515
List * list_copy_tail(const List *oldlist, int nskip)
Definition: list.c:1422
int first_partial_path
Definition: pathnodes.h:1406
List * subpaths
Definition: pathnodes.h:1404
List * lappend(List *list, void *datum)
Definition: list.c:321
bool parallel_aware
Definition: pathnodes.h:1149
Definition: pg_list.h:50

◆ add_paths_to_append_rel()

void add_paths_to_append_rel ( PlannerInfo root,
RelOptInfo rel,
List live_childrels 
)

Definition at line 1297 of file allpaths.c.

References accumulate_append_subpath(), add_partial_path(), add_path(), Assert, bms_equal(), bms_next_member(), RelOptInfo::cheapest_total_path, compare_pathkeys(), RelOptInfo::consider_parallel, create_append_path(), enable_parallel_append, fls(), generate_orderedappend_paths(), get_cheapest_parallel_safe_total_inner(), get_cheapest_parameterized_child_path(), IS_JOIN_REL, IS_SIMPLE_REL, lappend(), lfirst, linitial, list_concat(), list_length(), list_make1, Max, max_parallel_workers_per_gather, Min, NIL, Path::parallel_workers, Path::param_info, RelOptInfo::part_scheme, RelOptInfo::partial_pathlist, RelOptInfo::partitioned_child_rels, AppendPath::path, PATH_REQ_OUTER, Path::pathkeys, PATHKEYS_EQUAL, RelOptInfo::pathlist, RelOptInfo::relids, Path::rows, RTE_SUBQUERY, RelOptInfo::rtekind, PlannerInfo::simple_rel_array, subpath(), and Path::total_cost.

Referenced by apply_scanjoin_target_to_paths(), create_partitionwise_grouping_paths(), generate_partitionwise_join_paths(), and set_append_rel_pathlist().

1299 {
1300  List *subpaths = NIL;
1301  bool subpaths_valid = true;
1302  List *partial_subpaths = NIL;
1303  List *pa_partial_subpaths = NIL;
1304  List *pa_nonpartial_subpaths = NIL;
1305  bool partial_subpaths_valid = true;
1306  bool pa_subpaths_valid;
1307  List *all_child_pathkeys = NIL;
1308  List *all_child_outers = NIL;
1309  ListCell *l;
1310  List *partitioned_rels = NIL;
1311  double partial_rows = -1;
1312 
1313  /* If appropriate, consider parallel append */
1314  pa_subpaths_valid = enable_parallel_append && rel->consider_parallel;
1315 
1316  /*
1317  * AppendPath generated for partitioned tables must record the RT indexes
1318  * of partitioned tables that are direct or indirect children of this
1319  * Append rel.
1320  *
1321  * AppendPath may be for a sub-query RTE (UNION ALL), in which case, 'rel'
1322  * itself does not represent a partitioned relation, but the child sub-
1323  * queries may contain references to partitioned relations. The loop
1324  * below will look for such children and collect them in a list to be
1325  * passed to the path creation function. (This assumes that we don't need
1326  * to look through multiple levels of subquery RTEs; if we ever do, we
1327  * could consider stuffing the list we generate here into sub-query RTE's
1328  * RelOptInfo, just like we do for partitioned rels, which would be used
1329  * when populating our parent rel with paths. For the present, that
1330  * appears to be unnecessary.)
1331  */
1332  if (rel->part_scheme != NULL)
1333  {
1334  if (IS_SIMPLE_REL(rel))
1335  partitioned_rels = list_make1(rel->partitioned_child_rels);
1336  else if (IS_JOIN_REL(rel))
1337  {
1338  int relid = -1;
1339  List *partrels = NIL;
1340 
1341  /*
1342  * For a partitioned joinrel, concatenate the component rels'
1343  * partitioned_child_rels lists.
1344  */
1345  while ((relid = bms_next_member(rel->relids, relid)) >= 0)
1346  {
1347  RelOptInfo *component;
1348 
1349  Assert(relid >= 1 && relid < root->simple_rel_array_size);
1350  component = root->simple_rel_array[relid];
1351  Assert(component->part_scheme != NULL);
1352  Assert(list_length(component->partitioned_child_rels) >= 1);
1353  partrels = list_concat(partrels,
1354  component->partitioned_child_rels);
1355  }
1356 
1357  partitioned_rels = list_make1(partrels);
1358  }
1359 
1360  Assert(list_length(partitioned_rels) >= 1);
1361  }
1362 
1363  /*
1364  * For every non-dummy child, remember the cheapest path. Also, identify
1365  * all pathkeys (orderings) and parameterizations (required_outer sets)
1366  * available for the non-dummy member relations.
1367  */
1368  foreach(l, live_childrels)
1369  {
1370  RelOptInfo *childrel = lfirst(l);
1371  ListCell *lcp;
1372  Path *cheapest_partial_path = NULL;
1373 
1374  /*
1375  * For UNION ALLs with non-empty partitioned_child_rels, accumulate
1376  * the Lists of child relations.
1377  */
1378  if (rel->rtekind == RTE_SUBQUERY && childrel->partitioned_child_rels != NIL)
1379  partitioned_rels = lappend(partitioned_rels,
1380  childrel->partitioned_child_rels);
1381 
1382  /*
1383  * If child has an unparameterized cheapest-total path, add that to
1384  * the unparameterized Append path we are constructing for the parent.
1385  * If not, there's no workable unparameterized path.
1386  *
1387  * With partitionwise aggregates, the child rel's pathlist may be
1388  * empty, so don't assume that a path exists here.
1389  */
1390  if (childrel->pathlist != NIL &&
1391  childrel->cheapest_total_path->param_info == NULL)
1393  &subpaths, NULL);
1394  else
1395  subpaths_valid = false;
1396 
1397  /* Same idea, but for a partial plan. */
1398  if (childrel->partial_pathlist != NIL)
1399  {
1400  cheapest_partial_path = linitial(childrel->partial_pathlist);
1401  accumulate_append_subpath(cheapest_partial_path,
1402  &partial_subpaths, NULL);
1403  }
1404  else
1405  partial_subpaths_valid = false;
1406 
1407  /*
1408  * Same idea, but for a parallel append mixing partial and non-partial
1409  * paths.
1410  */
1411  if (pa_subpaths_valid)
1412  {
1413  Path *nppath = NULL;
1414 
1415  nppath =
1417 
1418  if (cheapest_partial_path == NULL && nppath == NULL)
1419  {
1420  /* Neither a partial nor a parallel-safe path? Forget it. */
1421  pa_subpaths_valid = false;
1422  }
1423  else if (nppath == NULL ||
1424  (cheapest_partial_path != NULL &&
1425  cheapest_partial_path->total_cost < nppath->total_cost))
1426  {
1427  /* Partial path is cheaper or the only option. */
1428  Assert(cheapest_partial_path != NULL);
1429  accumulate_append_subpath(cheapest_partial_path,
1430  &pa_partial_subpaths,
1431  &pa_nonpartial_subpaths);
1432 
1433  }
1434  else
1435  {
1436  /*
1437  * Either we've got only a non-partial path, or we think that
1438  * a single backend can execute the best non-partial path
1439  * faster than all the parallel backends working together can
1440  * execute the best partial path.
1441  *
1442  * It might make sense to be more aggressive here. Even if
1443  * the best non-partial path is more expensive than the best
1444  * partial path, it could still be better to choose the
1445  * non-partial path if there are several such paths that can
1446  * be given to different workers. For now, we don't try to
1447  * figure that out.
1448  */
1450  &pa_nonpartial_subpaths,
1451  NULL);
1452  }
1453  }
1454 
1455  /*
1456  * Collect lists of all the available path orderings and
1457  * parameterizations for all the children. We use these as a
1458  * heuristic to indicate which sort orderings and parameterizations we
1459  * should build Append and MergeAppend paths for.
1460  */
1461  foreach(lcp, childrel->pathlist)
1462  {
1463  Path *childpath = (Path *) lfirst(lcp);
1464  List *childkeys = childpath->pathkeys;
1465  Relids childouter = PATH_REQ_OUTER(childpath);
1466 
1467  /* Unsorted paths don't contribute to pathkey list */
1468  if (childkeys != NIL)
1469  {
1470  ListCell *lpk;
1471  bool found = false;
1472 
1473  /* Have we already seen this ordering? */
1474  foreach(lpk, all_child_pathkeys)
1475  {
1476  List *existing_pathkeys = (List *) lfirst(lpk);
1477 
1478  if (compare_pathkeys(existing_pathkeys,
1479  childkeys) == PATHKEYS_EQUAL)
1480  {
1481  found = true;
1482  break;
1483  }
1484  }
1485  if (!found)
1486  {
1487  /* No, so add it to all_child_pathkeys */
1488  all_child_pathkeys = lappend(all_child_pathkeys,
1489  childkeys);
1490  }
1491  }
1492 
1493  /* Unparameterized paths don't contribute to param-set list */
1494  if (childouter)
1495  {
1496  ListCell *lco;
1497  bool found = false;
1498 
1499  /* Have we already seen this param set? */
1500  foreach(lco, all_child_outers)
1501  {
1502  Relids existing_outers = (Relids) lfirst(lco);
1503 
1504  if (bms_equal(existing_outers, childouter))
1505  {
1506  found = true;
1507  break;
1508  }
1509  }
1510  if (!found)
1511  {
1512  /* No, so add it to all_child_outers */
1513  all_child_outers = lappend(all_child_outers,
1514  childouter);
1515  }
1516  }
1517  }
1518  }
1519 
1520  /*
1521  * If we found unparameterized paths for all children, build an unordered,
1522  * unparameterized Append path for the rel. (Note: this is correct even
1523  * if we have zero or one live subpath due to constraint exclusion.)
1524  */
1525  if (subpaths_valid)
1526  add_path(rel, (Path *) create_append_path(root, rel, subpaths, NIL,
1527  NIL, NULL, 0, false,
1528  partitioned_rels, -1));
1529 
1530  /*
1531  * Consider an append of unordered, unparameterized partial paths. Make
1532  * it parallel-aware if possible.
1533  */
1534  if (partial_subpaths_valid && partial_subpaths != NIL)
1535  {
1536  AppendPath *appendpath;
1537  ListCell *lc;
1538  int parallel_workers = 0;
1539 
1540  /* Find the highest number of workers requested for any subpath. */
1541  foreach(lc, partial_subpaths)
1542  {
1543  Path *path = lfirst(lc);
1544 
1545  parallel_workers = Max(parallel_workers, path->parallel_workers);
1546  }
1547  Assert(parallel_workers > 0);
1548 
1549  /*
1550  * If the use of parallel append is permitted, always request at least
1551  * log2(# of children) workers. We assume it can be useful to have
1552  * extra workers in this case because they will be spread out across
1553  * the children. The precise formula is just a guess, but we don't
1554  * want to end up with a radically different answer for a table with N
1555  * partitions vs. an unpartitioned table with the same data, so the
1556  * use of some kind of log-scaling here seems to make some sense.
1557  */
1559  {
1560  parallel_workers = Max(parallel_workers,
1561  fls(list_length(live_childrels)));
1562  parallel_workers = Min(parallel_workers,
1564  }
1565  Assert(parallel_workers > 0);
1566 
1567  /* Generate a partial append path. */
1568  appendpath = create_append_path(root, rel, NIL, partial_subpaths,
1569  NIL, NULL, parallel_workers,
1571  partitioned_rels, -1);
1572 
1573  /*
1574  * Make sure any subsequent partial paths use the same row count
1575  * estimate.
1576  */
1577  partial_rows = appendpath->path.rows;
1578 
1579  /* Add the path. */
1580  add_partial_path(rel, (Path *) appendpath);
1581  }
1582 
1583  /*
1584  * Consider a parallel-aware append using a mix of partial and non-partial
1585  * paths. (This only makes sense if there's at least one child which has
1586  * a non-partial path that is substantially cheaper than any partial path;
1587  * otherwise, we should use the append path added in the previous step.)
1588  */
1589  if (pa_subpaths_valid && pa_nonpartial_subpaths != NIL)
1590  {
1591  AppendPath *appendpath;
1592  ListCell *lc;
1593  int parallel_workers = 0;
1594 
1595  /*
1596  * Find the highest number of workers requested for any partial
1597  * subpath.
1598  */
1599  foreach(lc, pa_partial_subpaths)
1600  {
1601  Path *path = lfirst(lc);
1602 
1603  parallel_workers = Max(parallel_workers, path->parallel_workers);
1604  }
1605 
1606  /*
1607  * Same formula here as above. It's even more important in this
1608  * instance because the non-partial paths won't contribute anything to
1609  * the planned number of parallel workers.
1610  */
1611  parallel_workers = Max(parallel_workers,
1612  fls(list_length(live_childrels)));
1613  parallel_workers = Min(parallel_workers,
1615  Assert(parallel_workers > 0);
1616 
1617  appendpath = create_append_path(root, rel, pa_nonpartial_subpaths,
1618  pa_partial_subpaths,
1619  NIL, NULL, parallel_workers, true,
1620  partitioned_rels, partial_rows);
1621  add_partial_path(rel, (Path *) appendpath);
1622  }
1623 
1624  /*
1625  * Also build unparameterized ordered append paths based on the collected
1626  * list of child pathkeys.
1627  */
1628  if (subpaths_valid)
1629  generate_orderedappend_paths(root, rel, live_childrels,
1630  all_child_pathkeys,
1631  partitioned_rels);
1632 
1633  /*
1634  * Build Append paths for each parameterization seen among the child rels.
1635  * (This may look pretty expensive, but in most cases of practical
1636  * interest, the child rels will expose mostly the same parameterizations,
1637  * so that not that many cases actually get considered here.)
1638  *
1639  * The Append node itself cannot enforce quals, so all qual checking must
1640  * be done in the child paths. This means that to have a parameterized
1641  * Append path, we must have the exact same parameterization for each
1642  * child path; otherwise some children might be failing to check the
1643  * moved-down quals. To make them match up, we can try to increase the
1644  * parameterization of lesser-parameterized paths.
1645  */
1646  foreach(l, all_child_outers)
1647  {
1648  Relids required_outer = (Relids) lfirst(l);
1649  ListCell *lcr;
1650 
1651  /* Select the child paths for an Append with this parameterization */
1652  subpaths = NIL;
1653  subpaths_valid = true;
1654  foreach(lcr, live_childrels)
1655  {
1656  RelOptInfo *childrel = (RelOptInfo *) lfirst(lcr);
1657  Path *subpath;
1658 
1659  if (childrel->pathlist == NIL)
1660  {
1661  /* failed to make a suitable path for this child */
1662  subpaths_valid = false;
1663  break;
1664  }
1665 
1667  childrel,
1668  required_outer);
1669  if (subpath == NULL)
1670  {
1671  /* failed to make a suitable path for this child */
1672  subpaths_valid = false;
1673  break;
1674  }
1675  accumulate_append_subpath(subpath, &subpaths, NULL);
1676  }
1677 
1678  if (subpaths_valid)
1679  add_path(rel, (Path *)
1680  create_append_path(root, rel, subpaths, NIL,
1681  NIL, required_outer, 0, false,
1682  partitioned_rels, -1));
1683  }
1684 
1685  /*
1686  * When there is only a single child relation, the Append path can inherit
1687  * any ordering available for the child rel's path, so that it's useful to
1688  * consider ordered partial paths. Above we only considered the cheapest
1689  * partial path for each child, but let's also make paths using any
1690  * partial paths that have pathkeys.
1691  */
1692  if (list_length(live_childrels) == 1)
1693  {
1694  RelOptInfo *childrel = (RelOptInfo *) linitial(live_childrels);
1695 
1696  foreach(l, childrel->partial_pathlist)
1697  {
1698  Path *path = (Path *) lfirst(l);
1699  AppendPath *appendpath;
1700 
1701  /*
1702  * Skip paths with no pathkeys. Also skip the cheapest partial
1703  * path, since we already used that above.
1704  */
1705  if (path->pathkeys == NIL ||
1706  path == linitial(childrel->partial_pathlist))
1707  continue;
1708 
1709  appendpath = create_append_path(root, rel, NIL, list_make1(path),
1710  NIL, NULL,
1711  path->parallel_workers, true,
1712  partitioned_rels, partial_rows);
1713  add_partial_path(rel, (Path *) appendpath);
1714  }
1715  }
1716 }
#define NIL
Definition: pg_list.h:65
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
static Path * get_cheapest_parameterized_child_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: allpaths.c:1957
#define Min(x, y)
Definition: c.h:920
int bms_next_member(const Bitmapset *a, int prevbit)
Definition: bitmapset.c:1043
int parallel_workers
Definition: pathnodes.h:1151
ParamPathInfo * param_info
Definition: pathnodes.h:1147
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:643
List * list_concat(List *list1, const List *list2)
Definition: list.c:515
List * partial_pathlist
Definition: pathnodes.h:681
bool enable_parallel_append
Definition: costsize.c:141
PathKeysComparison compare_pathkeys(List *keys1, List *keys2)
Definition: pathkeys.c:285
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:638
int fls(int mask)
Definition: fls.c:55
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:203
#define list_make1(x1)
Definition: pg_list.h:227
#define linitial(l)
Definition: pg_list.h:195
struct Path * cheapest_total_path
Definition: pathnodes.h:683
#define PATH_REQ_OUTER(path)
Definition: pathnodes.h:1163
Relids relids
Definition: pathnodes.h:665
Path * get_cheapest_parallel_safe_total_inner(List *paths)
Definition: pathkeys.c:482
AppendPath * create_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *partial_subpaths, List *pathkeys, Relids required_outer, int parallel_workers, bool parallel_aware, List *partitioned_rels, double rows)
Definition: pathnode.c:1183
List * lappend(List *list, void *datum)
Definition: list.c:321
RTEKind rtekind
Definition: pathnodes.h:695
Cost total_cost
Definition: pathnodes.h:1156
List * pathkeys
Definition: pathnodes.h:1158
#define Max(x, y)
Definition: c.h:914
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
double rows
Definition: pathnodes.h:1154
static int list_length(const List *l)
Definition: pg_list.h:169
bool consider_parallel
Definition: pathnodes.h:673
Bitmapset * Relids
Definition: pathnodes.h:28
List * partitioned_child_rels
Definition: pathnodes.h:755
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:749
PartitionScheme part_scheme
Definition: pathnodes.h:742
List * pathlist
Definition: pathnodes.h:679
static void generate_orderedappend_paths(PlannerInfo *root, RelOptInfo *rel, List *live_childrels, List *all_child_pathkeys, List *partitioned_rels)
Definition: allpaths.c:1746
static void accumulate_append_subpath(Path *path, List **subpaths, List **special_subpaths)
Definition: allpaths.c:2045
int max_parallel_workers_per_gather
Definition: costsize.c:123
Definition: pg_list.h:50
Datum subpath(PG_FUNCTION_ARGS)
Definition: ltree_op.c:241
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:94

◆ check_output_expressions()

static void check_output_expressions ( Query subquery,
pushdown_safety_info safetyInfo 
)
static

Definition at line 3339 of file allpaths.c.

References contain_volatile_functions(), Query::distinctClause, TargetEntry::expr, expression_returns_set(), Query::hasDistinctOn, Query::hasTargetSRFs, Query::hasWindowFuncs, InvalidOid, lfirst, TargetEntry::resjunk, TargetEntry::resno, targetIsInAllPartitionLists(), targetIsInSortList(), Query::targetList, and pushdown_safety_info::unsafeColumns.

Referenced by subquery_is_pushdown_safe().

3340 {
3341  ListCell *lc;
3342 
3343  foreach(lc, subquery->targetList)
3344  {
3345  TargetEntry *tle = (TargetEntry *) lfirst(lc);
3346 
3347  if (tle->resjunk)
3348  continue; /* ignore resjunk columns */
3349 
3350  /* We need not check further if output col is already known unsafe */
3351  if (safetyInfo->unsafeColumns[tle->resno])
3352  continue;
3353 
3354  /* Functions returning sets are unsafe (point 1) */
3355  if (subquery->hasTargetSRFs &&
3356  expression_returns_set((Node *) tle->expr))
3357  {
3358  safetyInfo->unsafeColumns[tle->resno] = true;
3359  continue;
3360  }
3361 
3362  /* Volatile functions are unsafe (point 2) */
3363  if (contain_volatile_functions((Node *) tle->expr))
3364  {
3365  safetyInfo->unsafeColumns[tle->resno] = true;
3366  continue;
3367  }
3368 
3369  /* If subquery uses DISTINCT ON, check point 3 */
3370  if (subquery->hasDistinctOn &&
3371  !targetIsInSortList(tle, InvalidOid, subquery->distinctClause))
3372  {
3373  /* non-DISTINCT column, so mark it unsafe */
3374  safetyInfo->unsafeColumns[tle->resno] = true;
3375  continue;
3376  }
3377 
3378  /* If subquery uses window functions, check point 4 */
3379  if (subquery->hasWindowFuncs &&
3380  !targetIsInAllPartitionLists(tle, subquery))
3381  {
3382  /* not present in all PARTITION BY clauses, so mark it unsafe */
3383  safetyInfo->unsafeColumns[tle->resno] = true;
3384  continue;
3385  }
3386  }
3387 }
bool expression_returns_set(Node *clause)
Definition: nodeFuncs.c:669
Definition: nodes.h:529
bool * unsafeColumns
Definition: allpaths.c:56
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:726
bool hasDistinctOn
Definition: parsenodes.h:129
List * targetList
Definition: parsenodes.h:140
bool resjunk
Definition: primnodes.h:1414
List * distinctClause
Definition: parsenodes.h:156
static bool targetIsInAllPartitionLists(TargetEntry *tle, Query *query)
Definition: allpaths.c:3440
AttrNumber resno
Definition: primnodes.h:1408
#define InvalidOid
Definition: postgres_ext.h:36
bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList)
bool hasTargetSRFs
Definition: parsenodes.h:127
#define lfirst(lc)
Definition: pg_list.h:190
bool hasWindowFuncs
Definition: parsenodes.h:126
Expr * expr
Definition: primnodes.h:1407

◆ compare_tlist_datatypes()

static void compare_tlist_datatypes ( List tlist,
List colTypes,
pushdown_safety_info safetyInfo 
)
static

Definition at line 3407 of file allpaths.c.

References elog, ERROR, TargetEntry::expr, exprType(), lfirst, lfirst_oid, list_head(), lnext(), TargetEntry::resjunk, TargetEntry::resno, and pushdown_safety_info::unsafeColumns.

Referenced by subquery_is_pushdown_safe().

3409 {
3410  ListCell *l;
3411  ListCell *colType = list_head(colTypes);
3412 
3413  foreach(l, tlist)
3414  {
3415  TargetEntry *tle = (TargetEntry *) lfirst(l);
3416 
3417  if (tle->resjunk)
3418  continue; /* ignore resjunk columns */
3419  if (colType == NULL)
3420  elog(ERROR, "wrong number of tlist entries");
3421  if (exprType((Node *) tle->expr) != lfirst_oid(colType))
3422  safetyInfo->unsafeColumns[tle->resno] = true;
3423  colType = lnext(colTypes, colType);
3424  }
3425  if (colType != NULL)
3426  elog(ERROR, "wrong number of tlist entries");
3427 }
static ListCell * lnext(const List *l, const ListCell *c)
Definition: pg_list.h:321
Definition: nodes.h:529
bool * unsafeColumns
Definition: allpaths.c:56
bool resjunk
Definition: primnodes.h:1414
#define ERROR
Definition: elog.h:43
AttrNumber resno
Definition: primnodes.h:1408
static ListCell * list_head(const List *l)
Definition: pg_list.h:125
#define lfirst(lc)
Definition: pg_list.h:190
Expr * expr
Definition: primnodes.h:1407
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:41
#define elog(elevel,...)
Definition: elog.h:214
#define lfirst_oid(lc)
Definition: pg_list.h:192

◆ compute_parallel_worker()

int compute_parallel_worker ( RelOptInfo rel,
double  heap_pages,
double  index_pages,
int  max_workers 
)

Definition at line 3794 of file allpaths.c.

References Max, Min, min_parallel_index_scan_size, min_parallel_table_scan_size, RelOptInfo::rel_parallel_workers, RELOPT_BASEREL, and RelOptInfo::reloptkind.

Referenced by cost_index(), create_partial_bitmap_paths(), create_plain_partial_paths(), and plan_create_index_workers().

3796 {
3797  int parallel_workers = 0;
3798 
3799  /*
3800  * If the user has set the parallel_workers reloption, use that; otherwise
3801  * select a default number of workers.
3802  */
3803  if (rel->rel_parallel_workers != -1)
3804  parallel_workers = rel->rel_parallel_workers;
3805  else
3806  {
3807  /*
3808  * If the number of pages being scanned is insufficient to justify a
3809  * parallel scan, just return zero ... unless it's an inheritance
3810  * child. In that case, we want to generate a parallel path here
3811  * anyway. It might not be worthwhile just for this relation, but
3812  * when combined with all of its inheritance siblings it may well pay
3813  * off.
3814  */
3815  if (rel->reloptkind == RELOPT_BASEREL &&
3816  ((heap_pages >= 0 && heap_pages < min_parallel_table_scan_size) ||
3817  (index_pages >= 0 && index_pages < min_parallel_index_scan_size)))
3818  return 0;
3819 
3820  if (heap_pages >= 0)
3821  {
3822  int heap_parallel_threshold;
3823  int heap_parallel_workers = 1;
3824 
3825  /*
3826  * Select the number of workers based on the log of the size of
3827  * the relation. This probably needs to be a good deal more
3828  * sophisticated, but we need something here for now. Note that
3829  * the upper limit of the min_parallel_table_scan_size GUC is
3830  * chosen to prevent overflow here.
3831  */
3832  heap_parallel_threshold = Max(min_parallel_table_scan_size, 1);
3833  while (heap_pages >= (BlockNumber) (heap_parallel_threshold * 3))
3834  {
3835  heap_parallel_workers++;
3836  heap_parallel_threshold *= 3;
3837  if (heap_parallel_threshold > INT_MAX / 3)
3838  break; /* avoid overflow */
3839  }
3840 
3841  parallel_workers = heap_parallel_workers;
3842  }
3843 
3844  if (index_pages >= 0)
3845  {
3846  int index_parallel_workers = 1;
3847  int index_parallel_threshold;
3848 
3849  /* same calculation as for heap_pages above */
3850  index_parallel_threshold = Max(min_parallel_index_scan_size, 1);
3851  while (index_pages >= (BlockNumber) (index_parallel_threshold * 3))
3852  {
3853  index_parallel_workers++;
3854  index_parallel_threshold *= 3;
3855  if (index_parallel_threshold > INT_MAX / 3)
3856  break; /* avoid overflow */
3857  }
3858 
3859  if (parallel_workers > 0)
3860  parallel_workers = Min(parallel_workers, index_parallel_workers);
3861  else
3862  parallel_workers = index_parallel_workers;
3863  }
3864  }
3865 
3866  /* In no case use more than caller supplied maximum number of workers */
3867  parallel_workers = Min(parallel_workers, max_workers);
3868 
3869  return parallel_workers;
3870 }
RelOptKind reloptkind
Definition: pathnodes.h:662
#define Min(x, y)
Definition: c.h:920
uint32 BlockNumber
Definition: block.h:31
int min_parallel_index_scan_size
Definition: allpaths.c:65
int rel_parallel_workers
Definition: pathnodes.h:711
#define Max(x, y)
Definition: c.h:914
int min_parallel_table_scan_size
Definition: allpaths.c:64

◆ create_partial_bitmap_paths()

void create_partial_bitmap_paths ( PlannerInfo root,
RelOptInfo rel,
Path bitmapqual 
)

Definition at line 3758 of file allpaths.c.

References add_partial_path(), compute_bitmap_pages(), compute_parallel_worker(), create_bitmap_heap_path(), RelOptInfo::lateral_relids, and max_parallel_workers_per_gather.

Referenced by create_index_paths().

3760 {
3761  int parallel_workers;
3762  double pages_fetched;
3763 
3764  /* Compute heap pages for bitmap heap scan */
3765  pages_fetched = compute_bitmap_pages(root, rel, bitmapqual, 1.0,
3766  NULL, NULL);
3767 
3768  parallel_workers = compute_parallel_worker(rel, pages_fetched, -1,
3770 
3771  if (parallel_workers <= 0)
3772  return;
3773 
3774  add_partial_path(rel, (Path *) create_bitmap_heap_path(root, rel,
3775  bitmapqual, rel->lateral_relids, 1.0, parallel_workers));
3776 }
int compute_parallel_worker(RelOptInfo *rel, double heap_pages, double index_pages, int max_workers)
Definition: allpaths.c:3794
Relids lateral_relids
Definition: pathnodes.h:690
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:749
int max_parallel_workers_per_gather
Definition: costsize.c:123
double compute_bitmap_pages(PlannerInfo *root, RelOptInfo *baserel, Path *bitmapqual, int loop_count, Cost *cost, double *tuple)
Definition: costsize.c:5731
BitmapHeapPath * create_bitmap_heap_path(PlannerInfo *root, RelOptInfo *rel, Path *bitmapqual, Relids required_outer, double loop_count, int parallel_degree)
Definition: pathnode.c:1046

◆ create_plain_partial_paths()

static void create_plain_partial_paths ( PlannerInfo root,
RelOptInfo rel 
)
static

Definition at line 796 of file allpaths.c.

References add_partial_path(), compute_parallel_worker(), create_seqscan_path(), max_parallel_workers_per_gather, and RelOptInfo::pages.

Referenced by set_plain_rel_pathlist().

797 {
798  int parallel_workers;
799 
800  parallel_workers = compute_parallel_worker(rel, rel->pages, -1,
802 
803  /* If any limit was set to zero, the user doesn't want a parallel scan. */
804  if (parallel_workers <= 0)
805  return;
806 
807  /* Add an unordered partial path based on a parallel sequential scan. */
808  add_partial_path(rel, create_seqscan_path(root, rel, NULL, parallel_workers));
809 }
int compute_parallel_worker(RelOptInfo *rel, double heap_pages, double index_pages, int max_workers)
Definition: allpaths.c:3794
BlockNumber pages
Definition: pathnodes.h:704
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:749
int max_parallel_workers_per_gather
Definition: costsize.c:123
Path * create_seqscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer, int parallel_workers)
Definition: pathnode.c:929

◆ generate_gather_paths()

void generate_gather_paths ( PlannerInfo root,
RelOptInfo rel,
bool  override_rows 
)

Definition at line 2685 of file allpaths.c.

References add_path(), create_gather_merge_path(), create_gather_path(), lfirst, linitial, NIL, Path::parallel_workers, RelOptInfo::partial_pathlist, GatherMergePath::path, Path::pathkeys, RelOptInfo::reltarget, Path::rows, and subpath().

Referenced by generate_useful_gather_paths().

2686 {
2687  Path *cheapest_partial_path;
2688  Path *simple_gather_path;
2689  ListCell *lc;
2690  double rows;
2691  double *rowsp = NULL;
2692 
2693  /* If there are no partial paths, there's nothing to do here. */
2694  if (rel->partial_pathlist == NIL)
2695  return;
2696 
2697  /* Should we override the rel's rowcount estimate? */
2698  if (override_rows)
2699  rowsp = &rows;
2700 
2701  /*
2702  * The output of Gather is always unsorted, so there's only one partial
2703  * path of interest: the cheapest one. That will be the one at the front
2704  * of partial_pathlist because of the way add_partial_path works.
2705  */
2706  cheapest_partial_path = linitial(rel->partial_pathlist);
2707  rows =
2708  cheapest_partial_path->rows * cheapest_partial_path->parallel_workers;
2709  simple_gather_path = (Path *)
2710  create_gather_path(root, rel, cheapest_partial_path, rel->reltarget,
2711  NULL, rowsp);
2712  add_path(rel, simple_gather_path);
2713 
2714  /*
2715  * For each useful ordering, we can consider an order-preserving Gather
2716  * Merge.
2717  */
2718  foreach(lc, rel->partial_pathlist)
2719  {
2720  Path *subpath = (Path *) lfirst(lc);
2721  GatherMergePath *path;
2722 
2723  if (subpath->pathkeys == NIL)
2724  continue;
2725 
2726  rows = subpath->rows * subpath->parallel_workers;
2727  path = create_gather_merge_path(root, rel, subpath, rel->reltarget,
2728  subpath->pathkeys, NULL, rowsp);
2729  add_path(rel, &path->path);
2730  }
2731 }
#define NIL
Definition: pg_list.h:65
GatherPath * create_gather_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, Relids required_outer, double *rows)
Definition: pathnode.c:1845
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
int parallel_workers
Definition: pathnodes.h:1151
List * partial_pathlist
Definition: pathnodes.h:681
#define linitial(l)
Definition: pg_list.h:195
GatherMergePath * create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, List *pathkeys, Relids required_outer, double *rows)
Definition: pathnode.c:1754
List * pathkeys
Definition: pathnodes.h:1158
#define lfirst(lc)
Definition: pg_list.h:190
double rows
Definition: pathnodes.h:1154
struct PathTarget * reltarget
Definition: pathnodes.h:676
Datum subpath(PG_FUNCTION_ARGS)
Definition: ltree_op.c:241

◆ generate_orderedappend_paths()

static void generate_orderedappend_paths ( PlannerInfo root,
RelOptInfo rel,
List live_childrels,
List all_child_pathkeys,
List partitioned_rels 
)
static

Definition at line 1746 of file allpaths.c.

References accumulate_append_subpath(), add_path(), Assert, BackwardScanDirection, RelOptInfo::boundinfo, build_partition_pathkeys(), RelOptInfo::cheapest_total_path, create_append_path(), create_merge_append_path(), ForwardScanDirection, get_cheapest_path_for_pathkeys(), get_singleton_append_subpath(), IS_SIMPLE_REL, lappend(), lcons(), lfirst, NIL, RelOptInfo::nparts, Path::param_info, RelOptInfo::part_scheme, partitions_are_ordered(), pathkeys_contained_in(), RelOptInfo::pathlist, STARTUP_COST, and TOTAL_COST.

Referenced by add_paths_to_append_rel().

1750 {
1751  ListCell *lcp;
1752  List *partition_pathkeys = NIL;
1753  List *partition_pathkeys_desc = NIL;
1754  bool partition_pathkeys_partial = true;
1755  bool partition_pathkeys_desc_partial = true;
1756 
1757  /*
1758  * Some partitioned table setups may allow us to use an Append node
1759  * instead of a MergeAppend. This is possible in cases such as RANGE
1760  * partitioned tables where it's guaranteed that an earlier partition must
1761  * contain rows which come earlier in the sort order. To detect whether
1762  * this is relevant, build pathkey descriptions of the partition ordering,
1763  * for both forward and reverse scans.
1764  */
1765  if (rel->part_scheme != NULL && IS_SIMPLE_REL(rel) &&
1767  {
1768  partition_pathkeys = build_partition_pathkeys(root, rel,
1770  &partition_pathkeys_partial);
1771 
1772  partition_pathkeys_desc = build_partition_pathkeys(root, rel,
1774  &partition_pathkeys_desc_partial);
1775 
1776  /*
1777  * You might think we should truncate_useless_pathkeys here, but
1778  * allowing partition keys which are a subset of the query's pathkeys
1779  * can often be useful. For example, consider a table partitioned by
1780  * RANGE (a, b), and a query with ORDER BY a, b, c. If we have child
1781  * paths that can produce the a, b, c ordering (perhaps via indexes on
1782  * (a, b, c)) then it works to consider the appendrel output as
1783  * ordered by a, b, c.
1784  */
1785  }
1786 
1787  /* Now consider each interesting sort ordering */
1788  foreach(lcp, all_child_pathkeys)
1789  {
1790  List *pathkeys = (List *) lfirst(lcp);
1791  List *startup_subpaths = NIL;
1792  List *total_subpaths = NIL;
1793  bool startup_neq_total = false;
1794  ListCell *lcr;
1795  bool match_partition_order;
1796  bool match_partition_order_desc;
1797 
1798  /*
1799  * Determine if this sort ordering matches any partition pathkeys we
1800  * have, for both ascending and descending partition order. If the
1801  * partition pathkeys happen to be contained in pathkeys then it still
1802  * works, as described above, providing that the partition pathkeys
1803  * are complete and not just a prefix of the partition keys. (In such
1804  * cases we'll be relying on the child paths to have sorted the
1805  * lower-order columns of the required pathkeys.)
1806  */
1807  match_partition_order =
1808  pathkeys_contained_in(pathkeys, partition_pathkeys) ||
1809  (!partition_pathkeys_partial &&
1810  pathkeys_contained_in(partition_pathkeys, pathkeys));
1811 
1812  match_partition_order_desc = !match_partition_order &&
1813  (pathkeys_contained_in(pathkeys, partition_pathkeys_desc) ||
1814  (!partition_pathkeys_desc_partial &&
1815  pathkeys_contained_in(partition_pathkeys_desc, pathkeys)));
1816 
1817  /* Select the child paths for this ordering... */
1818  foreach(lcr, live_childrels)
1819  {
1820  RelOptInfo *childrel = (RelOptInfo *) lfirst(lcr);
1821  Path *cheapest_startup,
1822  *cheapest_total;
1823 
1824  /* Locate the right paths, if they are available. */
1825  cheapest_startup =
1827  pathkeys,
1828  NULL,
1829  STARTUP_COST,
1830  false);
1831  cheapest_total =
1833  pathkeys,
1834  NULL,
1835  TOTAL_COST,
1836  false);
1837 
1838  /*
1839  * If we can't find any paths with the right order just use the
1840  * cheapest-total path; we'll have to sort it later.
1841  */
1842  if (cheapest_startup == NULL || cheapest_total == NULL)
1843  {
1844  cheapest_startup = cheapest_total =
1845  childrel->cheapest_total_path;
1846  /* Assert we do have an unparameterized path for this child */
1847  Assert(cheapest_total->param_info == NULL);
1848  }
1849 
1850  /*
1851  * Notice whether we actually have different paths for the
1852  * "cheapest" and "total" cases; frequently there will be no point
1853  * in two create_merge_append_path() calls.
1854  */
1855  if (cheapest_startup != cheapest_total)
1856  startup_neq_total = true;
1857 
1858  /*
1859  * Collect the appropriate child paths. The required logic varies
1860  * for the Append and MergeAppend cases.
1861  */
1862  if (match_partition_order)
1863  {
1864  /*
1865  * We're going to make a plain Append path. We don't need
1866  * most of what accumulate_append_subpath would do, but we do
1867  * want to cut out child Appends or MergeAppends if they have
1868  * just a single subpath (and hence aren't doing anything
1869  * useful).
1870  */
1871  cheapest_startup = get_singleton_append_subpath(cheapest_startup);
1872  cheapest_total = get_singleton_append_subpath(cheapest_total);
1873 
1874  startup_subpaths = lappend(startup_subpaths, cheapest_startup);
1875  total_subpaths = lappend(total_subpaths, cheapest_total);
1876  }
1877  else if (match_partition_order_desc)
1878  {
1879  /*
1880  * As above, but we need to reverse the order of the children,
1881  * because nodeAppend.c doesn't know anything about reverse
1882  * ordering and will scan the children in the order presented.
1883  */
1884  cheapest_startup = get_singleton_append_subpath(cheapest_startup);
1885  cheapest_total = get_singleton_append_subpath(cheapest_total);
1886 
1887  startup_subpaths = lcons(cheapest_startup, startup_subpaths);
1888  total_subpaths = lcons(cheapest_total, total_subpaths);
1889  }
1890  else
1891  {
1892  /*
1893  * Otherwise, rely on accumulate_append_subpath to collect the
1894  * child paths for the MergeAppend.
1895  */
1896  accumulate_append_subpath(cheapest_startup,
1897  &startup_subpaths, NULL);
1898  accumulate_append_subpath(cheapest_total,
1899  &total_subpaths, NULL);
1900  }
1901  }
1902 
1903  /* ... and build the Append or MergeAppend paths */
1904  if (match_partition_order || match_partition_order_desc)
1905  {
1906  /* We only need Append */
1907  add_path(rel, (Path *) create_append_path(root,
1908  rel,
1909  startup_subpaths,
1910  NIL,
1911  pathkeys,
1912  NULL,
1913  0,
1914  false,
1915  partitioned_rels,
1916  -1));
1917  if (startup_neq_total)
1918  add_path(rel, (Path *) create_append_path(root,
1919  rel,
1920  total_subpaths,
1921  NIL,
1922  pathkeys,
1923  NULL,
1924  0,
1925  false,
1926  partitioned_rels,
1927  -1));
1928  }
1929  else
1930  {
1931  /* We need MergeAppend */
1932  add_path(rel, (Path *) create_merge_append_path(root,
1933  rel,
1934  startup_subpaths,
1935  pathkeys,
1936  NULL,
1937  partitioned_rels));
1938  if (startup_neq_total)
1939  add_path(rel, (Path *) create_merge_append_path(root,
1940  rel,
1941  total_subpaths,
1942  pathkeys,
1943  NULL,
1944  partitioned_rels));
1945  }
1946  }
1947 }
Path * get_cheapest_path_for_pathkeys(List *paths, List *pathkeys, Relids required_outer, CostSelector cost_criterion, bool require_parallel_safe)
Definition: pathkeys.c:404
#define NIL
Definition: pg_list.h:65
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
List * build_partition_pathkeys(PlannerInfo *root, RelOptInfo *partrel, ScanDirection scandir, bool *partialkeys)
Definition: pathkeys.c:699
ParamPathInfo * param_info
Definition: pathnodes.h:1147
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:638
struct Path * cheapest_total_path
Definition: pathnodes.h:683
int nparts
Definition: pathnodes.h:743
MergeAppendPath * create_merge_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *pathkeys, Relids required_outer, List *partitioned_rels)
Definition: pathnode.c:1345
static Path * get_singleton_append_subpath(Path *path)
Definition: allpaths.c:2091
AppendPath * create_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *partial_subpaths, List *pathkeys, Relids required_outer, int parallel_workers, bool parallel_aware, List *partitioned_rels, double rows)
Definition: pathnode.c:1183
List * lappend(List *list, void *datum)
Definition: list.c:321
bool pathkeys_contained_in(List *keys1, List *keys2)
Definition: pathkeys.c:324
struct PartitionBoundInfoData * boundinfo
Definition: pathnodes.h:746
List * lcons(void *datum, List *list)
Definition: list.c:453
bool partitions_are_ordered(PartitionBoundInfo boundinfo, int nparts)
Definition: partbounds.c:2750
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
PartitionScheme part_scheme
Definition: pathnodes.h:742
List * pathlist
Definition: pathnodes.h:679
static void accumulate_append_subpath(Path *path, List **subpaths, List **special_subpaths)
Definition: allpaths.c:2045
Definition: pg_list.h:50

◆ generate_partitionwise_join_paths()

void generate_partitionwise_join_paths ( PlannerInfo root,
RelOptInfo rel 
)

Definition at line 3882 of file allpaths.c.

References add_paths_to_append_rel(), Alias::aliasname, Assert, RelOptInfo::baserestrictinfo, bms_next_member(), RelOptInfo::cheapest_parameterized_paths, RelOptInfo::cheapest_startup_path, RelOptInfo::cheapest_total_path, check_stack_depth(), RestrictInfo::clause, RelOptInfo::consider_partitionwise_join, RangeTblEntry::eref, generate_partitionwise_join_paths(), i, JoinPath::innerjoinpath, MergePath::innersortkeys, IS_DUMMY_REL, IS_JOIN_REL, IS_PARTITIONED_REL, IsA, RelOptInfo::joininfo, JoinPath::joinrestrictinfo, lappend(), lfirst, list_free(), lnext(), mark_dummy_rel(), MergePath::materialize_inner, NIL, nodeTag, RelOptInfo::nparts, JoinPath::outerjoinpath, MergePath::outersortkeys, Path::param_info, Path::parent, PlannerInfo::parse, RelOptInfo::part_rels, Path::pathkeys, RelOptInfo::pathlist, Path::pathtype, ParamPathInfo::ppi_req_outer, print_expr(), print_pathkeys(), printf, RelOptInfo::relids, RelOptInfo::reltarget, RelOptInfo::rows, Path::rows, Query::rtable, set_cheapest(), PlannerInfo::simple_rte_array, Path::startup_cost, generate_unaccent_rules::stdout, subpath(), T_AggPath, T_AppendPath, T_BitmapAndPath, T_BitmapHeapPath, T_BitmapOrPath, T_CteScan, T_CustomPath, T_ForeignPath, T_FunctionScan, T_GatherMergePath, T_GatherPath, T_GroupingSetsPath, T_GroupPath, T_GroupResultPath, T_HashPath, T_IncrementalSortPath, T_IndexPath, T_LimitPath, T_LockRowsPath, T_MaterialPath, T_MergeAppendPath, T_MergePath, T_MinMaxAggPath, T_ModifyTablePath, T_NamedTuplestoreScan, T_NestPath, T_Path, T_ProjectionPath, T_ProjectSetPath, T_RecursiveUnionPath, T_Result, T_SampleScan, T_SeqScan, T_SetOpPath, T_SortPath, T_SubqueryScanPath, T_TableFuncScan, T_TidPath, T_UniquePath, T_UpperUniquePath, T_ValuesScan, T_WindowAggPath, T_WorkTableScan, Path::total_cost, and PathTarget::width.

Referenced by generate_partitionwise_join_paths(), merge_clump(), and standard_join_search().

3883 {
3884  List *live_children = NIL;
3885  int cnt_parts;
3886  int num_parts;
3887  RelOptInfo **part_rels;
3888 
3889  /* Handle only join relations here. */
3890  if (!IS_JOIN_REL(rel))
3891  return;
3892 
3893  /* We've nothing to do if the relation is not partitioned. */
3894  if (!IS_PARTITIONED_REL(rel))
3895  return;
3896 
3897  /* The relation should have consider_partitionwise_join set. */
3899 
3900  /* Guard against stack overflow due to overly deep partition hierarchy. */
3902 
3903  num_parts = rel->nparts;
3904  part_rels = rel->part_rels;
3905 
3906  /* Collect non-dummy child-joins. */
3907  for (cnt_parts = 0; cnt_parts < num_parts; cnt_parts++)
3908  {
3909  RelOptInfo *child_rel = part_rels[cnt_parts];
3910 
3911  /* If it's been pruned entirely, it's certainly dummy. */
3912  if (child_rel == NULL)
3913  continue;
3914 
3915  /* Add partitionwise join paths for partitioned child-joins. */
3916  generate_partitionwise_join_paths(root, child_rel);
3917 
3918  set_cheapest(child_rel);
3919 
3920  /* Dummy children will not be scanned, so ignore those. */
3921  if (IS_DUMMY_REL(child_rel))
3922  continue;
3923 
3924 #ifdef OPTIMIZER_DEBUG
3925  debug_print_rel(root, child_rel);
3926 #endif
3927 
3928  live_children = lappend(live_children, child_rel);
3929  }
3930 
3931  /* If all child-joins are dummy, parent join is also dummy. */
3932  if (!live_children)
3933  {
3934  mark_dummy_rel(rel);
3935  return;
3936  }
3937 
3938  /* Build additional paths for this rel from child-join paths. */
3939  add_paths_to_append_rel(root, rel, live_children);
3940  list_free(live_children);
3941 }
#define NIL
Definition: pg_list.h:65
void add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel, List *live_childrels)
Definition: allpaths.c:1297
void generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:3882
#define IS_JOIN_REL(rel)
Definition: pathnodes.h:643
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1418
void check_stack_depth(void)
Definition: postgres.c:3312
int nparts
Definition: pathnodes.h:743
List * lappend(List *list, void *datum)
Definition: list.c:321
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:244
bool consider_partitionwise_join
Definition: pathnodes.h:736
void mark_dummy_rel(RelOptInfo *rel)
Definition: joinrels.c:1261
#define Assert(condition)
Definition: c.h:738
struct RelOptInfo ** part_rels
Definition: pathnodes.h:750
#define IS_PARTITIONED_REL(rel)
Definition: pathnodes.h:766
void list_free(List *list)
Definition: list.c:1376
Definition: pg_list.h:50

◆ generate_useful_gather_paths()

void generate_useful_gather_paths ( PlannerInfo root,
RelOptInfo rel,
bool  override_rows 
)

Definition at line 2816 of file allpaths.c.

References add_path(), Assert, create_gather_merge_path(), create_incremental_sort_path(), create_sort_path(), enable_incremental_sort, generate_gather_paths(), get_useful_pathkeys_for_relation(), lfirst, linitial, list_length(), NIL, Path::parallel_workers, RelOptInfo::partial_pathlist, GatherMergePath::path, Path::pathkeys, pathkeys_count_contained_in(), RelOptInfo::reltarget, Path::rows, and subpath().

Referenced by apply_scanjoin_target_to_paths(), gather_grouping_paths(), merge_clump(), set_rel_pathlist(), and standard_join_search().

2817 {
2818  ListCell *lc;
2819  double rows;
2820  double *rowsp = NULL;
2821  List *useful_pathkeys_list = NIL;
2822  Path *cheapest_partial_path = NULL;
2823 
2824  /* If there are no partial paths, there's nothing to do here. */
2825  if (rel->partial_pathlist == NIL)
2826  return;
2827 
2828  /* Should we override the rel's rowcount estimate? */
2829  if (override_rows)
2830  rowsp = &rows;
2831 
2832  /* generate the regular gather (merge) paths */
2833  generate_gather_paths(root, rel, override_rows);
2834 
2835  /* consider incremental sort for interesting orderings */
2836  useful_pathkeys_list = get_useful_pathkeys_for_relation(root, rel);
2837 
2838  /* used for explicit (full) sort paths */
2839  cheapest_partial_path = linitial(rel->partial_pathlist);
2840 
2841  /*
2842  * Consider incremental sort paths for each interesting ordering.
2843  */
2844  foreach(lc, useful_pathkeys_list)
2845  {
2846  List *useful_pathkeys = lfirst(lc);
2847  ListCell *lc2;
2848  bool is_sorted;
2849  int presorted_keys;
2850 
2851  foreach(lc2, rel->partial_pathlist)
2852  {
2853  Path *subpath = (Path *) lfirst(lc2);
2854  GatherMergePath *path;
2855 
2856  /*
2857  * If the path has no ordering at all, then we can't use either
2858  * incremental sort or rely on implict sorting with a gather
2859  * merge.
2860  */
2861  if (subpath->pathkeys == NIL)
2862  continue;
2863 
2864  is_sorted = pathkeys_count_contained_in(useful_pathkeys,
2865  subpath->pathkeys,
2866  &presorted_keys);
2867 
2868  /*
2869  * We don't need to consider the case where a subpath is already
2870  * fully sorted because generate_gather_paths already creates a
2871  * gather merge path for every subpath that has pathkeys present.
2872  *
2873  * But since the subpath is already sorted, we know we don't need
2874  * to consider adding a sort (other either kind) on top of it, so
2875  * we can continue here.
2876  */
2877  if (is_sorted)
2878  continue;
2879 
2880  /*
2881  * Consider regular sort for the cheapest partial path (for each
2882  * useful pathkeys). We know the path is not sorted, because we'd
2883  * not get here otherwise.
2884  *
2885  * This is not redundant with the gather paths created in
2886  * generate_gather_paths, because that doesn't generate ordered
2887  * output. Here we add an explicit sort to match the useful
2888  * ordering.
2889  */
2890  if (cheapest_partial_path == subpath)
2891  {
2892  Path *tmp;
2893 
2894  tmp = (Path *) create_sort_path(root,
2895  rel,
2896  subpath,
2897  useful_pathkeys,
2898  -1.0);
2899 
2900  rows = tmp->rows * tmp->parallel_workers;
2901 
2902  path = create_gather_merge_path(root, rel,
2903  tmp,
2904  rel->reltarget,
2905  tmp->pathkeys,
2906  NULL,
2907  rowsp);
2908 
2909  add_path(rel, &path->path);
2910 
2911  /* Fall through */
2912  }
2913 
2914  /*
2915  * Consider incremental sort, but only when the subpath is already
2916  * partially sorted on a pathkey prefix.
2917  */
2918  if (enable_incremental_sort && presorted_keys > 0)
2919  {
2920  Path *tmp;
2921 
2922  /*
2923  * We should have already excluded pathkeys of length 1
2924  * because then presorted_keys > 0 would imply is_sorted was
2925  * true.
2926  */
2927  Assert(list_length(useful_pathkeys) != 1);
2928 
2929  tmp = (Path *) create_incremental_sort_path(root,
2930  rel,
2931  subpath,
2932  useful_pathkeys,
2933  presorted_keys,
2934  -1);
2935 
2936  path = create_gather_merge_path(root, rel,
2937  tmp,
2938  rel->reltarget,
2939  tmp->pathkeys,
2940  NULL,
2941  rowsp);
2942 
2943  add_path(rel, &path->path);
2944  }
2945  }
2946  }
2947 }
#define NIL
Definition: pg_list.h:65
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
bool enable_incremental_sort
Definition: costsize.c:131
SortPath * create_incremental_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, int presorted_keys, double limit_tuples)
Definition: pathnode.c:2769
int parallel_workers
Definition: pathnodes.h:1151
List * partial_pathlist
Definition: pathnodes.h:681
void generate_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
Definition: allpaths.c:2685
bool pathkeys_count_contained_in(List *keys1, List *keys2, int *n_common)
Definition: pathkeys.c:343
#define linitial(l)
Definition: pg_list.h:195
static List * get_useful_pathkeys_for_relation(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:2752
GatherMergePath * create_gather_merge_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, PathTarget *target, List *pathkeys, Relids required_outer, double *rows)
Definition: pathnode.c:1754
SortPath * create_sort_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, double limit_tuples)
Definition: pathnode.c:2818
List * pathkeys
Definition: pathnodes.h:1158
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
double rows
Definition: pathnodes.h:1154
static int list_length(const List *l)
Definition: pg_list.h:169
Definition: pg_list.h:50
struct PathTarget * reltarget
Definition: pathnodes.h:676
Datum subpath(PG_FUNCTION_ARGS)
Definition: ltree_op.c:241

◆ get_cheapest_parameterized_child_path()

static Path * get_cheapest_parameterized_child_path ( PlannerInfo root,
RelOptInfo rel,
Relids  required_outer 
)
static

Definition at line 1957 of file allpaths.c.

References Assert, bms_equal(), bms_is_subset(), compare_path_costs(), get_cheapest_path_for_pathkeys(), lfirst, NIL, PATH_REQ_OUTER, RelOptInfo::pathlist, reparameterize_path(), and TOTAL_COST.

Referenced by add_paths_to_append_rel().

1959 {
1960  Path *cheapest;
1961  ListCell *lc;
1962 
1963  /*
1964  * Look up the cheapest existing path with no more than the needed
1965  * parameterization. If it has exactly the needed parameterization, we're
1966  * done.
1967  */
1968  cheapest = get_cheapest_path_for_pathkeys(rel->pathlist,
1969  NIL,
1970  required_outer,
1971  TOTAL_COST,
1972  false);
1973  Assert(cheapest != NULL);
1974  if (bms_equal(PATH_REQ_OUTER(cheapest), required_outer))
1975  return cheapest;
1976 
1977  /*
1978  * Otherwise, we can "reparameterize" an existing path to match the given
1979  * parameterization, which effectively means pushing down additional
1980  * joinquals to be checked within the path's scan. However, some existing
1981  * paths might check the available joinquals already while others don't;
1982  * therefore, it's not clear which existing path will be cheapest after
1983  * reparameterization. We have to go through them all and find out.
1984  */
1985  cheapest = NULL;
1986  foreach(lc, rel->pathlist)
1987  {
1988  Path *path = (Path *) lfirst(lc);
1989 
1990  /* Can't use it if it needs more than requested parameterization */
1991  if (!bms_is_subset(PATH_REQ_OUTER(path), required_outer))
1992  continue;
1993 
1994  /*
1995  * Reparameterization can only increase the path's cost, so if it's
1996  * already more expensive than the current cheapest, forget it.
1997  */
1998  if (cheapest != NULL &&
1999  compare_path_costs(cheapest, path, TOTAL_COST) <= 0)
2000  continue;
2001 
2002  /* Reparameterize if needed, then recheck cost */
2003  if (!bms_equal(PATH_REQ_OUTER(path), required_outer))
2004  {
2005  path = reparameterize_path(root, path, required_outer, 1.0);
2006  if (path == NULL)
2007  continue; /* failed to reparameterize this one */
2008  Assert(bms_equal(PATH_REQ_OUTER(path), required_outer));
2009 
2010  if (cheapest != NULL &&
2011  compare_path_costs(cheapest, path, TOTAL_COST) <= 0)
2012  continue;
2013  }
2014 
2015  /* We have a new best path */
2016  cheapest = path;
2017  }
2018 
2019  /* Return the best path, or NULL if we found no suitable candidate */
2020  return cheapest;
2021 }
Path * get_cheapest_path_for_pathkeys(List *paths, List *pathkeys, Relids required_outer, CostSelector cost_criterion, bool require_parallel_safe)
Definition: pathkeys.c:404
#define NIL
Definition: pg_list.h:65
bool bms_is_subset(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:315
int compare_path_costs(Path *path1, Path *path2, CostSelector criterion)
Definition: pathnode.c:71
#define PATH_REQ_OUTER(path)
Definition: pathnodes.h:1163
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
Path * reparameterize_path(PlannerInfo *root, Path *path, Relids required_outer, double loop_count)
Definition: pathnode.c:3725
List * pathlist
Definition: pathnodes.h:679
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:94

◆ get_singleton_append_subpath()

static Path * get_singleton_append_subpath ( Path path)
static

Definition at line 2091 of file allpaths.c.

References Assert, IsA, linitial, list_length(), Path::parallel_aware, AppendPath::subpaths, and MergeAppendPath::subpaths.

Referenced by generate_orderedappend_paths().

2092 {
2093  Assert(!path->parallel_aware);
2094 
2095  if (IsA(path, AppendPath))
2096  {
2097  AppendPath *apath = (AppendPath *) path;
2098 
2099  if (list_length(apath->subpaths) == 1)
2100  return (Path *) linitial(apath->subpaths);
2101  }
2102  else if (IsA(path, MergeAppendPath))
2103  {
2104  MergeAppendPath *mpath = (MergeAppendPath *) path;
2105 
2106  if (list_length(mpath->subpaths) == 1)
2107  return (Path *) linitial(mpath->subpaths);
2108  }
2109 
2110  return path;
2111 }
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
List * subpaths
Definition: pathnodes.h:1404
#define linitial(l)
Definition: pg_list.h:195
#define Assert(condition)
Definition: c.h:738
static int list_length(const List *l)
Definition: pg_list.h:169
bool parallel_aware
Definition: pathnodes.h:1149

◆ get_useful_pathkeys_for_relation()

static List* get_useful_pathkeys_for_relation ( PlannerInfo root,
RelOptInfo rel 
)
static

Definition at line 2752 of file allpaths.c.

References find_em_expr_for_rel(), lappend(), lfirst, list_copy(), list_length(), list_truncate(), NIL, PathKey::pk_eclass, and PlannerInfo::query_pathkeys.

Referenced by generate_useful_gather_paths().

2753 {
2754  List *useful_pathkeys_list = NIL;
2755 
2756  /*
2757  * Considering query_pathkeys is always worth it, because it might allow
2758  * us to avoid a total sort when we have a partially presorted path
2759  * available.
2760  */
2761  if (root->query_pathkeys)
2762  {
2763  ListCell *lc;
2764  int npathkeys = 0; /* useful pathkeys */
2765 
2766  foreach(lc, root->query_pathkeys)
2767  {
2768  PathKey *pathkey = (PathKey *) lfirst(lc);
2769  EquivalenceClass *pathkey_ec = pathkey->pk_eclass;
2770 
2771  /*
2772  * We can only build an Incremental Sort for pathkeys which
2773  * contain an EC member in the current relation, so ignore any
2774  * suffix of the list as soon as we find a pathkey without an EC
2775  * member the relation.
2776  *
2777  * By still returning the prefix of the pathkeys list that does
2778  * meet criteria of EC membership in the current relation, we
2779  * enable not just an incremental sort on the entirety of
2780  * query_pathkeys but also incremental sort below a JOIN.
2781  */
2782  if (!find_em_expr_for_rel(pathkey_ec, rel))
2783  break;
2784 
2785  npathkeys++;
2786  }
2787 
2788  /*
2789  * The whole query_pathkeys list matches, so append it directly, to
2790  * allow comparing pathkeys easily by comparing list pointer. If we
2791  * have to truncate the pathkeys, we gotta do a copy though.
2792  */
2793  if (npathkeys == list_length(root->query_pathkeys))
2794  useful_pathkeys_list = lappend(useful_pathkeys_list,
2795  root->query_pathkeys);
2796  else if (npathkeys > 0)
2797  useful_pathkeys_list = lappend(useful_pathkeys_list,
2799  npathkeys));
2800  }
2801 
2802  return useful_pathkeys_list;
2803 }
#define NIL
Definition: pg_list.h:65
List * query_pathkeys
Definition: pathnodes.h:298
List * list_truncate(List *list, int new_size)
Definition: list.c:585
List * list_copy(const List *oldlist)
Definition: list.c:1403
List * lappend(List *list, void *datum)
Definition: list.c:321
Expr * find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel)
Definition: equivclass.c:782
#define lfirst(lc)
Definition: pg_list.h:190
EquivalenceClass * pk_eclass
Definition: pathnodes.h:1041
static int list_length(const List *l)
Definition: pg_list.h:169
Definition: pg_list.h:50

◆ has_multiple_baserels()

static bool has_multiple_baserels ( PlannerInfo root)
static

Definition at line 2151 of file allpaths.c.

References RELOPT_BASEREL, RelOptInfo::reloptkind, PlannerInfo::simple_rel_array, and PlannerInfo::simple_rel_array_size.

Referenced by set_subquery_pathlist().

2152 {
2153  int num_base_rels = 0;
2154  Index rti;
2155 
2156  for (rti = 1; rti < root->simple_rel_array_size; rti++)
2157  {
2158  RelOptInfo *brel = root->simple_rel_array[rti];
2159 
2160  if (brel == NULL)
2161  continue;
2162 
2163  /* ignore RTEs that are "other rels" */
2164  if (brel->reloptkind == RELOPT_BASEREL)
2165  if (++num_base_rels > 1)
2166  return true;
2167  }
2168  return false;
2169 }
RelOptKind reloptkind
Definition: pathnodes.h:662
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:203
int simple_rel_array_size
Definition: pathnodes.h:204
unsigned int Index
Definition: c.h:475

◆ make_one_rel()

RelOptInfo* make_one_rel ( PlannerInfo root,
List joinlist 
)

Definition at line 152 of file allpaths.c.

References PlannerInfo::all_baserels, Assert, bms_add_member(), bms_equal(), IS_DUMMY_REL, IS_SIMPLE_REL, make_rel_from_joinlist(), RelOptInfo::pages, RelOptInfo::relid, RelOptInfo::relids, RELOPT_BASEREL, RelOptInfo::reloptkind, set_base_rel_consider_startup(), set_base_rel_pathlists(), set_base_rel_sizes(), PlannerInfo::simple_rel_array, PlannerInfo::simple_rel_array_size, and PlannerInfo::total_table_pages.

Referenced by query_planner().

153 {
154  RelOptInfo *rel;
155  Index rti;
156  double total_pages;
157 
158  /*
159  * Construct the all_baserels Relids set.
160  */
161  root->all_baserels = NULL;
162  for (rti = 1; rti < root->simple_rel_array_size; rti++)
163  {
164  RelOptInfo *brel = root->simple_rel_array[rti];
165 
166  /* there may be empty slots corresponding to non-baserel RTEs */
167  if (brel == NULL)
168  continue;
169 
170  Assert(brel->relid == rti); /* sanity check on array */
171 
172  /* ignore RTEs that are "other rels" */
173  if (brel->reloptkind != RELOPT_BASEREL)
174  continue;
175 
176  root->all_baserels = bms_add_member(root->all_baserels, brel->relid);
177  }
178 
179  /* Mark base rels as to whether we care about fast-start plans */
181 
182  /*
183  * Compute size estimates and consider_parallel flags for each base rel.
184  */
185  set_base_rel_sizes(root);
186 
187  /*
188  * We should now have size estimates for every actual table involved in
189  * the query, and we also know which if any have been deleted from the
190  * query by join removal, pruned by partition pruning, or eliminated by
191  * constraint exclusion. So we can now compute total_table_pages.
192  *
193  * Note that appendrels are not double-counted here, even though we don't
194  * bother to distinguish RelOptInfos for appendrel parents, because the
195  * parents will have pages = 0.
196  *
197  * XXX if a table is self-joined, we will count it once per appearance,
198  * which perhaps is the wrong thing ... but that's not completely clear,
199  * and detecting self-joins here is difficult, so ignore it for now.
200  */
201  total_pages = 0;
202  for (rti = 1; rti < root->simple_rel_array_size; rti++)
203  {
204  RelOptInfo *brel = root->simple_rel_array[rti];
205 
206  if (brel == NULL)
207  continue;
208 
209  Assert(brel->relid == rti); /* sanity check on array */
210 
211  if (IS_DUMMY_REL(brel))
212  continue;
213 
214  if (IS_SIMPLE_REL(brel))
215  total_pages += (double) brel->pages;
216  }
217  root->total_table_pages = total_pages;
218 
219  /*
220  * Generate access paths for each base rel.
221  */
223 
224  /*
225  * Generate access paths for the entire join tree.
226  */
227  rel = make_rel_from_joinlist(root, joinlist);
228 
229  /*
230  * The result should join all and only the query's base rels.
231  */
232  Assert(bms_equal(rel->relids, root->all_baserels));
233 
234  return rel;
235 }
RelOptKind reloptkind
Definition: pathnodes.h:662
static void set_base_rel_sizes(PlannerInfo *root)
Definition: allpaths.c:291
static void set_base_rel_consider_startup(PlannerInfo *root)
Definition: allpaths.c:248
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:638
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:203
Relids all_baserels
Definition: pathnodes.h:227
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1418
static RelOptInfo * make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
Definition: allpaths.c:2957
Relids relids
Definition: pathnodes.h:665
double total_table_pages
Definition: pathnodes.h:333
int simple_rel_array_size
Definition: pathnodes.h:204
Index relid
Definition: pathnodes.h:693
static void set_base_rel_pathlists(PlannerInfo *root)
Definition: allpaths.c:334
unsigned int Index
Definition: c.h:475
BlockNumber pages
Definition: pathnodes.h:704
#define Assert(condition)
Definition: c.h:738
Bitmapset * bms_add_member(Bitmapset *a, int x)
Definition: bitmapset.c:736
bool bms_equal(const Bitmapset *a, const Bitmapset *b)
Definition: bitmapset.c:94

◆ make_rel_from_joinlist()

static RelOptInfo * make_rel_from_joinlist ( PlannerInfo root,
List joinlist 
)
static

Definition at line 2957 of file allpaths.c.

References elog, enable_geqo, ERROR, find_base_rel(), geqo(), geqo_threshold, PlannerInfo::initial_rels, IsA, join_search_hook, lappend(), lfirst, linitial, list_length(), NIL, nodeTag, and standard_join_search().

Referenced by make_one_rel().

2958 {
2959  int levels_needed;
2960  List *initial_rels;
2961  ListCell *jl;
2962 
2963  /*
2964  * Count the number of child joinlist nodes. This is the depth of the
2965  * dynamic-programming algorithm we must employ to consider all ways of
2966  * joining the child nodes.
2967  */
2968  levels_needed = list_length(joinlist);
2969 
2970  if (levels_needed <= 0)
2971  return NULL; /* nothing to do? */
2972 
2973  /*
2974  * Construct a list of rels corresponding to the child joinlist nodes.
2975  * This may contain both base rels and rels constructed according to
2976  * sub-joinlists.
2977  */
2978  initial_rels = NIL;
2979  foreach(jl, joinlist)
2980  {
2981  Node *jlnode = (Node *) lfirst(jl);
2982  RelOptInfo *thisrel;
2983 
2984  if (IsA(jlnode, RangeTblRef))
2985  {
2986  int varno = ((RangeTblRef *) jlnode)->rtindex;
2987 
2988  thisrel = find_base_rel(root, varno);
2989  }
2990  else if (IsA(jlnode, List))
2991  {
2992  /* Recurse to handle subproblem */
2993  thisrel = make_rel_from_joinlist(root, (List *) jlnode);
2994  }
2995  else
2996  {
2997  elog(ERROR, "unrecognized joinlist node type: %d",
2998  (int) nodeTag(jlnode));
2999  thisrel = NULL; /* keep compiler quiet */
3000  }
3001 
3002  initial_rels = lappend(initial_rels, thisrel);
3003  }
3004 
3005  if (levels_needed == 1)
3006  {
3007  /*
3008  * Single joinlist node, so we're done.
3009  */
3010  return (RelOptInfo *) linitial(initial_rels);
3011  }
3012  else
3013  {
3014  /*
3015  * Consider the different orders in which we could join the rels,
3016  * using a plugin, GEQO, or the regular join search code.
3017  *
3018  * We put the initial_rels list into a PlannerInfo field because
3019  * has_legal_joinclause() needs to look at it (ugly :-().
3020  */
3021  root->initial_rels = initial_rels;
3022 
3023  if (join_search_hook)
3024  return (*join_search_hook) (root, levels_needed, initial_rels);
3025  else if (enable_geqo && levels_needed >= geqo_threshold)
3026  return geqo(root, levels_needed, initial_rels);
3027  else
3028  return standard_join_search(root, levels_needed, initial_rels);
3029  }
3030 }
RelOptInfo * standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
Definition: allpaths.c:3062
#define NIL
Definition: pg_list.h:65
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
Definition: nodes.h:529
#define linitial(l)
Definition: pg_list.h:195
#define ERROR
Definition: elog.h:43
bool enable_geqo
Definition: allpaths.c:62
static RelOptInfo * make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
Definition: allpaths.c:2957
List * lappend(List *list, void *datum)
Definition: list.c:321
join_search_hook_type join_search_hook
Definition: allpaths.c:71
int geqo_threshold
Definition: allpaths.c:63
RelOptInfo * geqo(PlannerInfo *root, int number_of_rels, List *initial_rels)
Definition: geqo_main.c:67
#define lfirst(lc)
Definition: pg_list.h:190
static int list_length(const List *l)
Definition: pg_list.h:169
#define nodeTag(nodeptr)
Definition: nodes.h:534
#define elog(elevel,...)
Definition: elog.h:214
List * initial_rels
Definition: pathnodes.h:308
RelOptInfo * find_base_rel(PlannerInfo *root, int relid)
Definition: relnode.c:374
Definition: pg_list.h:50

◆ qual_is_pushdown_safe()

static bool qual_is_pushdown_safe ( Query subquery,
Index  rti,
Node qual,
pushdown_safety_info safetyInfo 
)
static

Definition at line 3482 of file allpaths.c.

References Assert, contain_leaked_vars(), contain_subplans(), contain_volatile_functions(), contain_window_function(), IsA, lfirst, list_free(), pull_var_clause(), PVC_INCLUDE_PLACEHOLDERS, pushdown_safety_info::unsafeColumns, pushdown_safety_info::unsafeLeaky, pushdown_safety_info::unsafeVolatile, Var::varattno, and Var::varno.

Referenced by set_subquery_pathlist().

3484 {
3485  bool safe = true;
3486  List *vars;
3487  ListCell *vl;
3488 
3489  /* Refuse subselects (point 1) */
3490  if (contain_subplans(qual))
3491  return false;
3492 
3493  /* Refuse volatile quals if we found they'd be unsafe (point 2) */
3494  if (safetyInfo->unsafeVolatile &&
3496  return false;
3497 
3498  /* Refuse leaky quals if told to (point 3) */
3499  if (safetyInfo->unsafeLeaky &&
3500  contain_leaked_vars(qual))
3501  return false;
3502 
3503  /*
3504  * It would be unsafe to push down window function calls, but at least for
3505  * the moment we could never see any in a qual anyhow. (The same applies
3506  * to aggregates, which we check for in pull_var_clause below.)
3507  */
3509 
3510  /*
3511  * Examine all Vars used in clause; since it's a restriction clause, all
3512  * such Vars must refer to subselect output columns.
3513  */
3515  foreach(vl, vars)
3516  {
3517  Var *var = (Var *) lfirst(vl);
3518 
3519  /*
3520  * XXX Punt if we find any PlaceHolderVars in the restriction clause.
3521  * It's not clear whether a PHV could safely be pushed down, and even
3522  * less clear whether such a situation could arise in any cases of
3523  * practical interest anyway. So for the moment, just refuse to push
3524  * down.
3525  */
3526  if (!IsA(var, Var))
3527  {
3528  safe = false;
3529  break;
3530  }
3531 
3532  Assert(var->varno == rti);
3533  Assert(var->varattno >= 0);
3534 
3535  /* Check point 4 */
3536  if (var->varattno == 0)
3537  {
3538  safe = false;
3539  break;
3540  }
3541 
3542  /* Check point 5 */
3543  if (safetyInfo->unsafeColumns[var->varattno])
3544  {
3545  safe = false;
3546  break;
3547  }
3548  }
3549 
3550  list_free(vars);
3551 
3552  return safe;
3553 }
bool contain_leaked_vars(Node *clause)
Definition: clauses.c:1329
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
AttrNumber varattno
Definition: primnodes.h:186
bool * unsafeColumns
Definition: allpaths.c:56
List * pull_var_clause(Node *node, int flags)
Definition: var.c:535
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:726
Definition: primnodes.h:181
bool contain_subplans(Node *clause)
Definition: clauses.c:612
bool contain_window_function(Node *clause)
Definition: clauses.c:496
Index varno
Definition: primnodes.h:184
#define PVC_INCLUDE_PLACEHOLDERS
Definition: optimizer.h:175
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
void list_free(List *list)
Definition: list.c:1376
Definition: regcomp.c:224
Definition: pg_list.h:50

◆ recurse_push_qual()

static void recurse_push_qual ( Node setOp,
Query topquery,
RangeTblEntry rte,
Index  rti,
Node qual 
)
static

Definition at line 3606 of file allpaths.c.

References Assert, elog, ERROR, IsA, SetOperationStmt::larg, nodeTag, SetOperationStmt::rarg, rt_fetch, Query::rtable, RangeTblRef::rtindex, RangeTblEntry::subquery, and subquery_push_qual().

Referenced by subquery_push_qual().

3608 {
3609  if (IsA(setOp, RangeTblRef))
3610  {
3611  RangeTblRef *rtr = (RangeTblRef *) setOp;
3612  RangeTblEntry *subrte = rt_fetch(rtr->rtindex, topquery->rtable);
3613  Query *subquery = subrte->subquery;
3614 
3615  Assert(subquery != NULL);
3616  subquery_push_qual(subquery, rte, rti, qual);
3617  }
3618  else if (IsA(setOp, SetOperationStmt))
3619  {
3620  SetOperationStmt *op = (SetOperationStmt *) setOp;
3621 
3622  recurse_push_qual(op->larg, topquery, rte, rti, qual);
3623  recurse_push_qual(op->rarg, topquery, rte, rti, qual);
3624  }
3625  else
3626  {
3627  elog(ERROR, "unrecognized node type: %d",
3628  (int) nodeTag(setOp));
3629  }
3630 }
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
List * rtable
Definition: parsenodes.h:137
#define ERROR
Definition: elog.h:43
#define rt_fetch(rangetable_index, rangetable)
Definition: parsetree.h:31
#define Assert(condition)
Definition: c.h:738
static void subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:3559
static void recurse_push_qual(Node *setOp, Query *topquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:3606
#define nodeTag(nodeptr)
Definition: nodes.h:534
Query * subquery
Definition: parsenodes.h:1011
#define elog(elevel,...)
Definition: elog.h:214

◆ recurse_pushdown_safe()

static bool recurse_pushdown_safe ( Node setOp,
Query topquery,
pushdown_safety_info safetyInfo 
)
static

Definition at line 3272 of file allpaths.c.

References Assert, elog, ERROR, IsA, SetOperationStmt::larg, nodeTag, SetOperationStmt::op, SetOperationStmt::rarg, rt_fetch, Query::rtable, RangeTblRef::rtindex, SETOP_EXCEPT, RangeTblEntry::subquery, and subquery_is_pushdown_safe().

Referenced by subquery_is_pushdown_safe().

3274 {
3275  if (IsA(setOp, RangeTblRef))
3276  {
3277  RangeTblRef *rtr = (RangeTblRef *) setOp;
3278  RangeTblEntry *rte = rt_fetch(rtr->rtindex, topquery->rtable);
3279  Query *subquery = rte->subquery;
3280 
3281  Assert(subquery != NULL);
3282  return subquery_is_pushdown_safe(subquery, topquery, safetyInfo);
3283  }
3284  else if (IsA(setOp, SetOperationStmt))
3285  {
3286  SetOperationStmt *op = (SetOperationStmt *) setOp;
3287 
3288  /* EXCEPT is no good (point 2 for subquery_is_pushdown_safe) */
3289  if (op->op == SETOP_EXCEPT)
3290  return false;
3291  /* Else recurse */
3292  if (!recurse_pushdown_safe(op->larg, topquery, safetyInfo))
3293  return false;
3294  if (!recurse_pushdown_safe(op->rarg, topquery, safetyInfo))
3295  return false;
3296  }
3297  else
3298  {
3299  elog(ERROR, "unrecognized node type: %d",
3300  (int) nodeTag(setOp));
3301  }
3302  return true;
3303 }
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
static bool recurse_pushdown_safe(Node *setOp, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3272
List * rtable
Definition: parsenodes.h:137
#define ERROR
Definition: elog.h:43
#define rt_fetch(rangetable_index, rangetable)
Definition: parsetree.h:31
#define Assert(condition)
Definition: c.h:738
SetOperation op
Definition: parsenodes.h:1658
#define nodeTag(nodeptr)
Definition: nodes.h:534
static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3220
Query * subquery
Definition: parsenodes.h:1011
#define elog(elevel,...)
Definition: elog.h:214

◆ remove_unused_subquery_outputs()

static void remove_unused_subquery_outputs ( Query subquery,
RelOptInfo rel 
)
static

Definition at line 3653 of file allpaths.c.

References RelOptInfo::baserestrictinfo, bms_is_member(), RestrictInfo::clause, contain_volatile_functions(), Query::distinctClause, TargetEntry::expr, exprCollation(), expression_returns_set(), PathTarget::exprs, exprType(), exprTypmod(), FirstLowInvalidHeapAttributeNumber, Query::hasDistinctOn, Query::hasTargetSRFs, lfirst, makeNullConst(), pull_varattnos(), RelOptInfo::relid, RelOptInfo::reltarget, TargetEntry::resjunk, TargetEntry::resno, TargetEntry::ressortgroupref, Query::setOperations, and Query::targetList.

Referenced by set_subquery_pathlist().

3654 {
3655  Bitmapset *attrs_used = NULL;
3656  ListCell *lc;
3657 
3658  /*
3659  * Do nothing if subquery has UNION/INTERSECT/EXCEPT: in principle we
3660  * could update all the child SELECTs' tlists, but it seems not worth the
3661  * trouble presently.
3662  */
3663  if (subquery->setOperations)
3664  return;
3665 
3666  /*
3667  * If subquery has regular DISTINCT (not DISTINCT ON), we're wasting our
3668  * time: all its output columns must be used in the distinctClause.
3669  */
3670  if (subquery->distinctClause && !subquery->hasDistinctOn)
3671  return;
3672 
3673  /*
3674  * Collect a bitmap of all the output column numbers used by the upper
3675  * query.
3676  *
3677  * Add all the attributes needed for joins or final output. Note: we must
3678  * look at rel's targetlist, not the attr_needed data, because attr_needed
3679  * isn't computed for inheritance child rels, cf set_append_rel_size().
3680  * (XXX might be worth changing that sometime.)
3681  */
3682  pull_varattnos((Node *) rel->reltarget->exprs, rel->relid, &attrs_used);
3683 
3684  /* Add all the attributes used by un-pushed-down restriction clauses. */
3685  foreach(lc, rel->baserestrictinfo)
3686  {
3687  RestrictInfo *rinfo = (RestrictInfo *) lfirst(lc);
3688 
3689  pull_varattnos((Node *) rinfo->clause, rel->relid, &attrs_used);
3690  }
3691 
3692  /*
3693  * If there's a whole-row reference to the subquery, we can't remove
3694  * anything.
3695  */
3697  return;
3698 
3699  /*
3700  * Run through the tlist and zap entries we don't need. It's okay to
3701  * modify the tlist items in-place because set_subquery_pathlist made a
3702  * copy of the subquery.
3703  */
3704  foreach(lc, subquery->targetList)
3705  {
3706  TargetEntry *tle = (TargetEntry *) lfirst(lc);
3707  Node *texpr = (Node *) tle->expr;
3708 
3709  /*
3710  * If it has a sortgroupref number, it's used in some sort/group
3711  * clause so we'd better not remove it. Also, don't remove any
3712  * resjunk columns, since their reason for being has nothing to do
3713  * with anybody reading the subquery's output. (It's likely that
3714  * resjunk columns in a sub-SELECT would always have ressortgroupref
3715  * set, but even if they don't, it seems imprudent to remove them.)
3716  */
3717  if (tle->ressortgroupref || tle->resjunk)
3718  continue;
3719 
3720  /*
3721  * If it's used by the upper query, we can't remove it.
3722  */
3724  attrs_used))
3725  continue;
3726 
3727  /*
3728  * If it contains a set-returning function, we can't remove it since
3729  * that could change the number of rows returned by the subquery.
3730  */
3731  if (subquery->hasTargetSRFs &&
3732  expression_returns_set(texpr))
3733  continue;
3734 
3735  /*
3736  * If it contains volatile functions, we daren't remove it for fear
3737  * that the user is expecting their side-effects to happen.
3738  */
3739  if (contain_volatile_functions(texpr))
3740  continue;
3741 
3742  /*
3743  * OK, we don't need it. Replace the expression with a NULL constant.
3744  * Preserve the exposed type of the expression, in case something
3745  * looks at the rowtype of the subquery's result.
3746  */
3747  tle->expr = (Expr *) makeNullConst(exprType(texpr),
3748  exprTypmod(texpr),
3749  exprCollation(texpr));
3750  }
3751 }
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:275
List * baserestrictinfo
Definition: pathnodes.h:727
bool expression_returns_set(Node *clause)
Definition: nodeFuncs.c:669
Definition: nodes.h:529
#define FirstLowInvalidHeapAttributeNumber
Definition: sysattr.h:27
bool contain_volatile_functions(Node *clause)
Definition: clauses.c:726
void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos)
Definition: var.c:219
bool hasDistinctOn
Definition: parsenodes.h:129
List * targetList
Definition: parsenodes.h:140
Const * makeNullConst(Oid consttype, int32 consttypmod, Oid constcollid)
Definition: makefuncs.c:337
bool resjunk
Definition: primnodes.h:1414
List * distinctClause
Definition: parsenodes.h:156
AttrNumber resno
Definition: primnodes.h:1408
Index relid
Definition: pathnodes.h:693
Expr * clause
Definition: pathnodes.h:1985
List * exprs
Definition: pathnodes.h:1074
bool hasTargetSRFs
Definition: parsenodes.h:127
#define lfirst(lc)
Definition: pg_list.h:190
Expr * expr
Definition: primnodes.h:1407
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:41
Oid exprCollation(const Node *expr)
Definition: nodeFuncs.c:719
Node * setOperations
Definition: parsenodes.h:166
Index ressortgroupref
Definition: primnodes.h:1410
bool bms_is_member(int x, const Bitmapset *a)
Definition: bitmapset.c:427
struct PathTarget * reltarget
Definition: pathnodes.h:676

◆ set_append_rel_pathlist()

static void set_append_rel_pathlist ( PlannerInfo root,
RelOptInfo rel,
Index  rti,
RangeTblEntry rte 
)
static

Definition at line 1221 of file allpaths.c.

References add_paths_to_append_rel(), PlannerInfo::append_rel_list, AppendRelInfo::child_relid, RelOptInfo::consider_parallel, IS_DUMMY_REL, lappend(), lfirst, list_concat(), NIL, AppendRelInfo::parent_relid, RelOptInfo::part_scheme, RelOptInfo::partitioned_child_rels, set_rel_pathlist(), PlannerInfo::simple_rel_array, and PlannerInfo::simple_rte_array.

Referenced by set_rel_pathlist().

1223 {
1224  int parentRTindex = rti;
1225  List *live_childrels = NIL;
1226  ListCell *l;
1227 
1228  /*
1229  * Generate access paths for each member relation, and remember the
1230  * non-dummy children.
1231  */
1232  foreach(l, root->append_rel_list)
1233  {
1234  AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
1235  int childRTindex;
1236  RangeTblEntry *childRTE;
1237  RelOptInfo *childrel;
1238 
1239  /* append_rel_list contains all append rels; ignore others */
1240  if (appinfo->parent_relid != parentRTindex)
1241  continue;
1242 
1243  /* Re-locate the child RTE and RelOptInfo */
1244  childRTindex = appinfo->child_relid;
1245  childRTE = root->simple_rte_array[childRTindex];
1246  childrel = root->simple_rel_array[childRTindex];
1247 
1248  /*
1249  * If set_append_rel_size() decided the parent appendrel was
1250  * parallel-unsafe at some point after visiting this child rel, we
1251  * need to propagate the unsafety marking down to the child, so that
1252  * we don't generate useless partial paths for it.
1253  */
1254  if (!rel->consider_parallel)
1255  childrel->consider_parallel = false;
1256 
1257  /*
1258  * Compute the child's access paths.
1259  */
1260  set_rel_pathlist(root, childrel, childRTindex, childRTE);
1261 
1262  /*
1263  * If child is dummy, ignore it.
1264  */
1265  if (IS_DUMMY_REL(childrel))
1266  continue;
1267 
1268  /* Bubble up childrel's partitioned children. */
1269  if (rel->part_scheme)
1270  rel->partitioned_child_rels =
1272  childrel->partitioned_child_rels);
1273 
1274  /*
1275  * Child is live, so add it to the live_childrels list for use below.
1276  */
1277  live_childrels = lappend(live_childrels, childrel);
1278  }
1279 
1280  /* Add paths to the append relation. */
1281  add_paths_to_append_rel(root, rel, live_childrels);
1282 }
#define NIL
Definition: pg_list.h:65
void add_paths_to_append_rel(PlannerInfo *root, RelOptInfo *rel, List *live_childrels)
Definition: allpaths.c:1297
List * list_concat(List *list1, const List *list2)
Definition: list.c:515
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:203
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1418
List * lappend(List *list, void *datum)
Definition: list.c:321
RangeTblEntry ** simple_rte_array
Definition: pathnodes.h:211
List * append_rel_list
Definition: pathnodes.h:290
static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:470
#define lfirst(lc)
Definition: pg_list.h:190
bool consider_parallel
Definition: pathnodes.h:673
List * partitioned_child_rels
Definition: pathnodes.h:755
PartitionScheme part_scheme
Definition: pathnodes.h:742
Index child_relid
Definition: pathnodes.h:2230
Index parent_relid
Definition: pathnodes.h:2229
Definition: pg_list.h:50

◆ set_append_rel_size()

static void set_append_rel_size ( PlannerInfo root,
RelOptInfo rel,
Index  rti,
RangeTblEntry rte 
)
static

Definition at line 942 of file allpaths.c.

References add_child_rel_equivalences(), adjust_appendrel_attrs(), PlannerInfo::append_rel_list, Assert, RelOptInfo::attr_needed, RelOptInfo::attr_widths, check_stack_depth(), AppendRelInfo::child_relid, RelOptInfo::consider_parallel, RelOptInfo::consider_partitionwise_join, enable_partitionwise_join, PathTarget::exprs, exprType(), exprTypmod(), find_base_rel(), forboth, get_typavgwidth(), PlannerInfo::glob, RelOptInfo::has_eclass_joins, has_useful_pathkeys(), i, InvalidAttrNumber, IS_DUMMY_REL, IS_SIMPLE_REL, IsA, RelOptInfo::joininfo, lfirst, list_make1_int, RelOptInfo::max_attr, RelOptInfo::min_attr, palloc0(), PlannerGlobal::parallelModeOK, AppendRelInfo::parent_relid, RelOptInfo::partitioned_child_rels, pfree(), relation_excluded_by_constraints(), RelOptInfo::relid, RangeTblEntry::relkind, RELOPT_BASEREL, RELOPT_OTHER_MEMBER_REL, RelOptInfo::reloptkind, RelOptInfo::reltarget, RelOptInfo::rows, set_dummy_rel_pathlist(), set_rel_consider_parallel(), set_rel_size(), PlannerInfo::simple_rte_array, RelOptInfo::tuples, Var::varattno, and PathTarget::width.

Referenced by set_rel_size().

944 {
945  int parentRTindex = rti;
946  bool has_live_children;
947  double parent_rows;
948  double parent_size;
949  double *parent_attrsizes;
950  int nattrs;
951  ListCell *l;
952 
953  /* Guard against stack overflow due to overly deep inheritance tree. */
955 
956  Assert(IS_SIMPLE_REL(rel));
957 
958  /*
959  * Initialize partitioned_child_rels to contain this RT index.
960  *
961  * Note that during the set_append_rel_pathlist() phase, we will bubble up
962  * the indexes of partitioned relations that appear down in the tree, so
963  * that when we've created Paths for all the children, the root
964  * partitioned table's list will contain all such indexes.
965  */
966  if (rte->relkind == RELKIND_PARTITIONED_TABLE)
968 
969  /*
970  * If this is a partitioned baserel, set the consider_partitionwise_join
971  * flag; currently, we only consider partitionwise joins with the baserel
972  * if its targetlist doesn't contain a whole-row Var.
973  */
975  rel->reloptkind == RELOPT_BASEREL &&
976  rte->relkind == RELKIND_PARTITIONED_TABLE &&
977  rel->attr_needed[InvalidAttrNumber - rel->min_attr] == NULL)
978  rel->consider_partitionwise_join = true;
979 
980  /*
981  * Initialize to compute size estimates for whole append relation.
982  *
983  * We handle width estimates by weighting the widths of different child
984  * rels proportionally to their number of rows. This is sensible because
985  * the use of width estimates is mainly to compute the total relation
986  * "footprint" if we have to sort or hash it. To do this, we sum the
987  * total equivalent size (in "double" arithmetic) and then divide by the
988  * total rowcount estimate. This is done separately for the total rel
989  * width and each attribute.
990  *
991  * Note: if you consider changing this logic, beware that child rels could
992  * have zero rows and/or width, if they were excluded by constraints.
993  */
994  has_live_children = false;
995  parent_rows = 0;
996  parent_size = 0;
997  nattrs = rel->max_attr - rel->min_attr + 1;
998  parent_attrsizes = (double *) palloc0(nattrs * sizeof(double));
999 
1000  foreach(l, root->append_rel_list)
1001  {
1002  AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
1003  int childRTindex;
1004  RangeTblEntry *childRTE;
1005  RelOptInfo *childrel;
1006  ListCell *parentvars;
1007  ListCell *childvars;
1008 
1009  /* append_rel_list contains all append rels; ignore others */
1010  if (appinfo->parent_relid != parentRTindex)
1011  continue;
1012 
1013  childRTindex = appinfo->child_relid;
1014  childRTE = root->simple_rte_array[childRTindex];
1015 
1016  /*
1017  * The child rel's RelOptInfo was already created during
1018  * add_other_rels_to_query.
1019  */
1020  childrel = find_base_rel(root, childRTindex);
1022 
1023  /* We may have already proven the child to be dummy. */
1024  if (IS_DUMMY_REL(childrel))
1025  continue;
1026 
1027  /*
1028  * We have to copy the parent's targetlist and quals to the child,
1029  * with appropriate substitution of variables. However, the
1030  * baserestrictinfo quals were already copied/substituted when the
1031  * child RelOptInfo was built. So we don't need any additional setup
1032  * before applying constraint exclusion.
1033  */
1034  if (relation_excluded_by_constraints(root, childrel, childRTE))
1035  {
1036  /*
1037  * This child need not be scanned, so we can omit it from the
1038  * appendrel.
1039  */
1040  set_dummy_rel_pathlist(childrel);
1041  continue;
1042  }
1043 
1044  /*
1045  * Constraint exclusion failed, so copy the parent's join quals and
1046  * targetlist to the child, with appropriate variable substitutions.
1047  *
1048  * NB: the resulting childrel->reltarget->exprs may contain arbitrary
1049  * expressions, which otherwise would not occur in a rel's targetlist.
1050  * Code that might be looking at an appendrel child must cope with
1051  * such. (Normally, a rel's targetlist would only include Vars and
1052  * PlaceHolderVars.) XXX we do not bother to update the cost or width
1053  * fields of childrel->reltarget; not clear if that would be useful.
1054  */
1055  childrel->joininfo = (List *)
1057  (Node *) rel->joininfo,
1058  1, &appinfo);
1059  childrel->reltarget->exprs = (List *)
1061  (Node *) rel->reltarget->exprs,
1062  1, &appinfo);
1063 
1064  /*
1065  * We have to make child entries in the EquivalenceClass data
1066  * structures as well. This is needed either if the parent
1067  * participates in some eclass joins (because we will want to consider
1068  * inner-indexscan joins on the individual children) or if the parent
1069  * has useful pathkeys (because we should try to build MergeAppend
1070  * paths that produce those sort orderings).
1071  */
1072  if (rel->has_eclass_joins || has_useful_pathkeys(root, rel))
1073  add_child_rel_equivalences(root, appinfo, rel, childrel);
1074  childrel->has_eclass_joins = rel->has_eclass_joins;
1075 
1076  /*
1077  * Note: we could compute appropriate attr_needed data for the child's
1078  * variables, by transforming the parent's attr_needed through the
1079  * translated_vars mapping. However, currently there's no need
1080  * because attr_needed is only examined for base relations not
1081  * otherrels. So we just leave the child's attr_needed empty.
1082  */
1083 
1084  /*
1085  * If we consider partitionwise joins with the parent rel, do the same
1086  * for partitioned child rels.
1087  *
1088  * Note: here we abuse the consider_partitionwise_join flag by setting
1089  * it for child rels that are not themselves partitioned. We do so to
1090  * tell try_partitionwise_join() that the child rel is sufficiently
1091  * valid to be used as a per-partition input, even if it later gets
1092  * proven to be dummy. (It's not usable until we've set up the
1093  * reltarget and EC entries, which we just did.)
1094  */
1095  if (rel->consider_partitionwise_join)
1096  childrel->consider_partitionwise_join = true;
1097 
1098  /*
1099  * If parallelism is allowable for this query in general, see whether
1100  * it's allowable for this childrel in particular. But if we've
1101  * already decided the appendrel is not parallel-safe as a whole,
1102  * there's no point in considering parallelism for this child. For
1103  * consistency, do this before calling set_rel_size() for the child.
1104  */
1105  if (root->glob->parallelModeOK && rel->consider_parallel)
1106  set_rel_consider_parallel(root, childrel, childRTE);
1107 
1108  /*
1109  * Compute the child's size.
1110  */
1111  set_rel_size(root, childrel, childRTindex, childRTE);
1112 
1113  /*
1114  * It is possible that constraint exclusion detected a contradiction
1115  * within a child subquery, even though we didn't prove one above. If
1116  * so, we can skip this child.
1117  */
1118  if (IS_DUMMY_REL(childrel))
1119  continue;
1120 
1121  /* We have at least one live child. */
1122  has_live_children = true;
1123 
1124  /*
1125  * If any live child is not parallel-safe, treat the whole appendrel
1126  * as not parallel-safe. In future we might be able to generate plans
1127  * in which some children are farmed out to workers while others are
1128  * not; but we don't have that today, so it's a waste to consider
1129  * partial paths anywhere in the appendrel unless it's all safe.
1130  * (Child rels visited before this one will be unmarked in
1131  * set_append_rel_pathlist().)
1132  */
1133  if (!childrel->consider_parallel)
1134  rel->consider_parallel = false;
1135 
1136  /*
1137  * Accumulate size information from each live child.
1138  */
1139  Assert(childrel->rows > 0);
1140 
1141  parent_rows += childrel->rows;
1142  parent_size += childrel->reltarget->width * childrel->rows;
1143 
1144  /*
1145  * Accumulate per-column estimates too. We need not do anything for
1146  * PlaceHolderVars in the parent list. If child expression isn't a
1147  * Var, or we didn't record a width estimate for it, we have to fall
1148  * back on a datatype-based estimate.
1149  *
1150  * By construction, child's targetlist is 1-to-1 with parent's.
1151  */
1152  forboth(parentvars, rel->reltarget->exprs,
1153  childvars, childrel->reltarget->exprs)
1154  {
1155  Var *parentvar = (Var *) lfirst(parentvars);
1156  Node *childvar = (Node *) lfirst(childvars);
1157 
1158  if (IsA(parentvar, Var))
1159  {
1160  int pndx = parentvar->varattno - rel->min_attr;
1161  int32 child_width = 0;
1162 
1163  if (IsA(childvar, Var) &&
1164  ((Var *) childvar)->varno == childrel->relid)
1165  {
1166  int cndx = ((Var *) childvar)->varattno - childrel->min_attr;
1167 
1168  child_width = childrel->attr_widths[cndx];
1169  }
1170  if (child_width <= 0)
1171  child_width = get_typavgwidth(exprType(childvar),
1172  exprTypmod(childvar));
1173  Assert(child_width > 0);
1174  parent_attrsizes[pndx] += child_width * childrel->rows;
1175  }
1176  }
1177  }
1178 
1179  if (has_live_children)
1180  {
1181  /*
1182  * Save the finished size estimates.
1183  */
1184  int i;
1185 
1186  Assert(parent_rows > 0);
1187  rel->rows = parent_rows;
1188  rel->reltarget->width = rint(parent_size / parent_rows);
1189  for (i = 0; i < nattrs; i++)
1190  rel->attr_widths[i] = rint(parent_attrsizes[i] / parent_rows);
1191 
1192  /*
1193  * Set "raw tuples" count equal to "rows" for the appendrel; needed
1194  * because some places assume rel->tuples is valid for any baserel.
1195  */
1196  rel->tuples = parent_rows;
1197 
1198  /*
1199  * Note that we leave rel->pages as zero; this is important to avoid
1200  * double-counting the appendrel tree in total_table_pages.
1201  */
1202  }
1203  else
1204  {
1205  /*
1206  * All children were excluded by constraints, so mark the whole
1207  * appendrel dummy. We must do this in this phase so that the rel's
1208  * dummy-ness is visible when we generate paths for other rels.
1209  */
1211  }
1212 
1213  pfree(parent_attrsizes);
1214 }
bool has_eclass_joins
Definition: pathnodes.h:733
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
#define forboth(cell1, list1, cell2, list2)
Definition: pg_list.h:419
RelOptKind reloptkind
Definition: pathnodes.h:662
Relids * attr_needed
Definition: pathnodes.h:698
int32 exprTypmod(const Node *expr)
Definition: nodeFuncs.c:275
double tuples
Definition: pathnodes.h:705
bool relation_excluded_by_constraints(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: plancat.c:1387
Definition: nodes.h:529
AttrNumber varattno
Definition: primnodes.h:186
void add_child_rel_equivalences(PlannerInfo *root, AppendRelInfo *appinfo, RelOptInfo *parent_rel, RelOptInfo *child_rel)
Definition: equivclass.c:2256
Definition: primnodes.h:181
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:638
signed int int32
Definition: c.h:355
void pfree(void *pointer)
Definition: mcxt.c:1056
bool parallelModeOK
Definition: pathnodes.h:143
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1418
static void set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:591
static void set_dummy_rel_pathlist(RelOptInfo *rel)
Definition: allpaths.c:2125
List * joininfo
Definition: pathnodes.h:731
void check_stack_depth(void)
Definition: postgres.c:3312
PlannerGlobal * glob
Definition: pathnodes.h:181
#define list_make1_int(x1)
Definition: pg_list.h:238
Index relid
Definition: pathnodes.h:693
RangeTblEntry ** simple_rte_array
Definition: pathnodes.h:211
List * exprs
Definition: pathnodes.h:1074
bool consider_partitionwise_join
Definition: pathnodes.h:736
void * palloc0(Size size)
Definition: mcxt.c:980
List * append_rel_list
Definition: pathnodes.h:290
int32 get_typavgwidth(Oid typid, int32 typmod)
Definition: lsyscache.c:2466
double rows
Definition: pathnodes.h:668
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
bool enable_partitionwise_join
Definition: costsize.c:139
Oid exprType(const Node *expr)
Definition: nodeFuncs.c:41
bool consider_parallel
Definition: pathnodes.h:673
#define InvalidAttrNumber
Definition: attnum.h:23
List * partitioned_child_rels
Definition: pathnodes.h:755
AttrNumber max_attr
Definition: pathnodes.h:697
int i
bool has_useful_pathkeys(PlannerInfo *root, RelOptInfo *rel)
Definition: pathkeys.c:1910
Index child_relid
Definition: pathnodes.h:2230
RelOptInfo * find_base_rel(PlannerInfo *root, int relid)
Definition: relnode.c:374
Index parent_relid
Definition: pathnodes.h:2229
int32 * attr_widths
Definition: pathnodes.h:699
Definition: pg_list.h:50
struct PathTarget * reltarget
Definition: pathnodes.h:676
static void set_rel_size(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:361
Node * adjust_appendrel_attrs(PlannerInfo *root, Node *node, int nappinfos, AppendRelInfo **appinfos)
Definition: appendinfo.c:194
AttrNumber min_attr
Definition: pathnodes.h:696

◆ set_base_rel_consider_startup()

static void set_base_rel_consider_startup ( PlannerInfo root)
static

Definition at line 248 of file allpaths.c.

References bms_get_singleton_member(), RelOptInfo::consider_param_startup, find_base_rel(), JOIN_ANTI, PlannerInfo::join_info_list, JOIN_SEMI, SpecialJoinInfo::jointype, lfirst, and SpecialJoinInfo::syn_righthand.

Referenced by make_one_rel().

249 {
250  /*
251  * Since parameterized paths can only be used on the inside of a nestloop
252  * join plan, there is usually little value in considering fast-start
253  * plans for them. However, for relations that are on the RHS of a SEMI
254  * or ANTI join, a fast-start plan can be useful because we're only going
255  * to care about fetching one tuple anyway.
256  *
257  * To minimize growth of planning time, we currently restrict this to
258  * cases where the RHS is a single base relation, not a join; there is no
259  * provision for consider_param_startup to get set at all on joinrels.
260  * Also we don't worry about appendrels. costsize.c's costing rules for
261  * nestloop semi/antijoins don't consider such cases either.
262  */
263  ListCell *lc;
264 
265  foreach(lc, root->join_info_list)
266  {
267  SpecialJoinInfo *sjinfo = (SpecialJoinInfo *) lfirst(lc);
268  int varno;
269 
270  if ((sjinfo->jointype == JOIN_SEMI || sjinfo->jointype == JOIN_ANTI) &&
271  bms_get_singleton_member(sjinfo->syn_righthand, &varno))
272  {
273  RelOptInfo *rel = find_base_rel(root, varno);
274 
275  rel->consider_param_startup = true;
276  }
277  }
278 }
List * join_info_list
Definition: pathnodes.h:283
bool consider_param_startup
Definition: pathnodes.h:672
bool bms_get_singleton_member(const Bitmapset *a, int *member)
Definition: bitmapset.c:615
Relids syn_righthand
Definition: pathnodes.h:2178
#define lfirst(lc)
Definition: pg_list.h:190
JoinType jointype
Definition: pathnodes.h:2179
RelOptInfo * find_base_rel(PlannerInfo *root, int relid)
Definition: relnode.c:374

◆ set_base_rel_pathlists()

static void set_base_rel_pathlists ( PlannerInfo root)
static

Definition at line 334 of file allpaths.c.

References Assert, RelOptInfo::relid, RELOPT_BASEREL, RelOptInfo::reloptkind, set_rel_pathlist(), PlannerInfo::simple_rel_array, PlannerInfo::simple_rel_array_size, and PlannerInfo::simple_rte_array.

Referenced by make_one_rel().

335 {
336  Index rti;
337 
338  for (rti = 1; rti < root->simple_rel_array_size; rti++)
339  {
340  RelOptInfo *rel = root->simple_rel_array[rti];
341 
342  /* there may be empty slots corresponding to non-baserel RTEs */
343  if (rel == NULL)
344  continue;
345 
346  Assert(rel->relid == rti); /* sanity check on array */
347 
348  /* ignore RTEs that are "other rels" */
349  if (rel->reloptkind != RELOPT_BASEREL)
350  continue;
351 
352  set_rel_pathlist(root, rel, rti, root->simple_rte_array[rti]);
353  }
354 }
RelOptKind reloptkind
Definition: pathnodes.h:662
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:203
int simple_rel_array_size
Definition: pathnodes.h:204
Index relid
Definition: pathnodes.h:693
RangeTblEntry ** simple_rte_array
Definition: pathnodes.h:211
unsigned int Index
Definition: c.h:475
static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:470
#define Assert(condition)
Definition: c.h:738

◆ set_base_rel_sizes()

static void set_base_rel_sizes ( PlannerInfo root)
static

Definition at line 291 of file allpaths.c.

References Assert, PlannerInfo::glob, PlannerGlobal::parallelModeOK, RelOptInfo::relid, RELOPT_BASEREL, RelOptInfo::reloptkind, set_rel_consider_parallel(), set_rel_size(), PlannerInfo::simple_rel_array, PlannerInfo::simple_rel_array_size, and PlannerInfo::simple_rte_array.

Referenced by make_one_rel().

292 {
293  Index rti;
294 
295  for (rti = 1; rti < root->simple_rel_array_size; rti++)
296  {
297  RelOptInfo *rel = root->simple_rel_array[rti];
298  RangeTblEntry *rte;
299 
300  /* there may be empty slots corresponding to non-baserel RTEs */
301  if (rel == NULL)
302  continue;
303 
304  Assert(rel->relid == rti); /* sanity check on array */
305 
306  /* ignore RTEs that are "other rels" */
307  if (rel->reloptkind != RELOPT_BASEREL)
308  continue;
309 
310  rte = root->simple_rte_array[rti];
311 
312  /*
313  * If parallelism is allowable for this query in general, see whether
314  * it's allowable for this rel in particular. We have to do this
315  * before set_rel_size(), because (a) if this rel is an inheritance
316  * parent, set_append_rel_size() will use and perhaps change the rel's
317  * consider_parallel flag, and (b) for some RTE types, set_rel_size()
318  * goes ahead and makes paths immediately.
319  */
320  if (root->glob->parallelModeOK)
321  set_rel_consider_parallel(root, rel, rte);
322 
323  set_rel_size(root, rel, rti, rte);
324  }
325 }
RelOptKind reloptkind
Definition: pathnodes.h:662
struct RelOptInfo ** simple_rel_array
Definition: pathnodes.h:203
bool parallelModeOK
Definition: pathnodes.h:143
static void set_rel_consider_parallel(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:591
PlannerGlobal * glob
Definition: pathnodes.h:181
int simple_rel_array_size
Definition: pathnodes.h:204
Index relid
Definition: pathnodes.h:693
RangeTblEntry ** simple_rte_array
Definition: pathnodes.h:211
unsigned int Index
Definition: c.h:475
#define Assert(condition)
Definition: c.h:738
static void set_rel_size(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:361

◆ set_cte_pathlist()

static void set_cte_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 2500 of file allpaths.c.

References add_path(), Assert, create_ctescan_path(), PlannerInfo::cte_plan_ids, RangeTblEntry::ctelevelsup, Query::cteList, RangeTblEntry::ctename, CommonTableExpr::ctename, elog, ERROR, PlannerInfo::glob, RelOptInfo::lateral_relids, lfirst, list_length(), list_nth(), list_nth_int(), PlannerInfo::parent_root, PlannerInfo::parse, Plan::plan_rows, set_cte_size_estimates(), and PlannerGlobal::subplans.

Referenced by set_rel_size().

2501 {
2502  Plan *cteplan;
2503  PlannerInfo *cteroot;
2504  Index levelsup;
2505  int ndx;
2506  ListCell *lc;
2507  int plan_id;
2508  Relids required_outer;
2509 
2510  /*
2511  * Find the referenced CTE, and locate the plan previously made for it.
2512  */
2513  levelsup = rte->ctelevelsup;
2514  cteroot = root;
2515  while (levelsup-- > 0)
2516  {
2517  cteroot = cteroot->parent_root;
2518  if (!cteroot) /* shouldn't happen */
2519  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
2520  }
2521 
2522  /*
2523  * Note: cte_plan_ids can be shorter than cteList, if we are still working
2524  * on planning the CTEs (ie, this is a side-reference from another CTE).
2525  * So we mustn't use forboth here.
2526  */
2527  ndx = 0;
2528  foreach(lc, cteroot->parse->cteList)
2529  {
2530  CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
2531 
2532  if (strcmp(cte->ctename, rte->ctename) == 0)
2533  break;
2534  ndx++;
2535  }
2536  if (lc == NULL) /* shouldn't happen */
2537  elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
2538  if (ndx >= list_length(cteroot->cte_plan_ids))
2539  elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
2540  plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
2541  Assert(plan_id > 0);
2542  cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1);
2543 
2544  /* Mark rel with estimated output rows, width, etc */
2545  set_cte_size_estimates(root, rel, cteplan->plan_rows);
2546 
2547  /*
2548  * We don't support pushing join clauses into the quals of a CTE scan, but
2549  * it could still have required parameterization due to LATERAL refs in
2550  * its tlist.
2551  */
2552  required_outer = rel->lateral_relids;
2553 
2554  /* Generate appropriate path */
2555  add_path(rel, create_ctescan_path(root, rel, required_outer));
2556 }
double plan_rows
Definition: plannodes.h:129
Query * parse
Definition: pathnodes.h:179
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
PlannerInfo * parent_root
Definition: pathnodes.h:185
void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel, double cte_rows)
Definition: costsize.c:5307
static int list_nth_int(const List *list, int n)
Definition: pg_list.h:288
Relids lateral_relids
Definition: pathnodes.h:690
#define ERROR
Definition: elog.h:43
static void * list_nth(const List *list, int n)
Definition: pg_list.h:277
List * subplans
Definition: pathnodes.h:111
PlannerGlobal * glob
Definition: pathnodes.h:181
List * cte_plan_ids
Definition: pathnodes.h:261
unsigned int Index
Definition: c.h:475
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
static int list_length(const List *l)
Definition: pg_list.h:169
Index ctelevelsup
Definition: parsenodes.h:1080
List * cteList
Definition: parsenodes.h:135
char * ctename
Definition: parsenodes.h:1079
#define elog(elevel,...)
Definition: elog.h:214
Path * create_ctescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1990

◆ set_dummy_rel_pathlist()

static void set_dummy_rel_pathlist ( RelOptInfo rel)
static

Definition at line 2125 of file allpaths.c.

References add_path(), create_append_path(), RelOptInfo::lateral_relids, NIL, RelOptInfo::partial_pathlist, RelOptInfo::pathlist, RelOptInfo::reltarget, RelOptInfo::rows, set_cheapest(), and PathTarget::width.

Referenced by set_append_rel_size(), set_rel_size(), and set_subquery_pathlist().

2126 {
2127  /* Set dummy size estimates --- we leave attr_widths[] as zeroes */
2128  rel->rows = 0;
2129  rel->reltarget->width = 0;
2130 
2131  /* Discard any pre-existing paths; no further need for them */
2132  rel->pathlist = NIL;
2133  rel->partial_pathlist = NIL;
2134 
2135  /* Set up the dummy path */
2136  add_path(rel, (Path *) create_append_path(NULL, rel, NIL, NIL,
2137  NIL, rel->lateral_relids,
2138  0, false, NIL, -1));
2139 
2140  /*
2141  * We set the cheapest-path fields immediately, just in case they were
2142  * pointing at some discarded path. This is redundant when we're called
2143  * from set_rel_size(), but not when called from elsewhere, and doing it
2144  * twice is harmless anyway.
2145  */
2146  set_cheapest(rel);
2147 }
#define NIL
Definition: pg_list.h:65
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
List * partial_pathlist
Definition: pathnodes.h:681
Relids lateral_relids
Definition: pathnodes.h:690
AppendPath * create_append_path(PlannerInfo *root, RelOptInfo *rel, List *subpaths, List *partial_subpaths, List *pathkeys, Relids required_outer, int parallel_workers, bool parallel_aware, List *partitioned_rels, double rows)
Definition: pathnode.c:1183
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:244
double rows
Definition: pathnodes.h:668
List * pathlist
Definition: pathnodes.h:679
struct PathTarget * reltarget
Definition: pathnodes.h:676

◆ set_foreign_pathlist()

static void set_foreign_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 924 of file allpaths.c.

References RelOptInfo::fdwroutine, FdwRoutine::GetForeignPaths, and RangeTblEntry::relid.

Referenced by set_rel_pathlist().

925 {
926  /* Call the FDW's GetForeignPaths function to generate path(s) */
927  rel->fdwroutine->GetForeignPaths(root, rel, rte->relid);
928 }
struct FdwRoutine * fdwroutine
Definition: pathnodes.h:718
GetForeignPaths_function GetForeignPaths
Definition: fdwapi.h:189

◆ set_foreign_size()

static void set_foreign_size ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 904 of file allpaths.c.

References clamp_row_est(), RelOptInfo::fdwroutine, FdwRoutine::GetForeignRelSize, Max, RangeTblEntry::relid, RelOptInfo::rows, set_foreign_size_estimates(), and RelOptInfo::tuples.

Referenced by set_rel_size().

905 {
906  /* Mark rel with estimated output rows, width, etc */
907  set_foreign_size_estimates(root, rel);
908 
909  /* Let FDW adjust the size estimates, if it can */
910  rel->fdwroutine->GetForeignRelSize(root, rel, rte->relid);
911 
912  /* ... but do not let it set the rows estimate to zero */
913  rel->rows = clamp_row_est(rel->rows);
914 
915  /* also, make sure rel->tuples is not insane relative to rel->rows */
916  rel->tuples = Max(rel->tuples, rel->rows);
917 }
double tuples
Definition: pathnodes.h:705
struct FdwRoutine * fdwroutine
Definition: pathnodes.h:718
GetForeignRelSize_function GetForeignRelSize
Definition: fdwapi.h:188
double rows
Definition: pathnodes.h:668
#define Max(x, y)
Definition: c.h:914
void set_foreign_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5406
double clamp_row_est(double nrows)
Definition: costsize.c:190

◆ set_function_pathlist()

static void set_function_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 2388 of file allpaths.c.

References add_path(), build_expression_pathkey(), create_functionscan_path(), PathTarget::exprs, RangeTblEntry::funcordinality, IsA, RelOptInfo::lateral_relids, lfirst, RelOptInfo::max_attr, NIL, RelOptInfo::relid, RelOptInfo::relids, RelOptInfo::reltarget, Var::varattno, Var::varlevelsup, and Var::varno.

Referenced by set_rel_pathlist().

2389 {
2390  Relids required_outer;
2391  List *pathkeys = NIL;
2392 
2393  /*
2394  * We don't support pushing join clauses into the quals of a function
2395  * scan, but it could still have required parameterization due to LATERAL
2396  * refs in the function expression.
2397  */
2398  required_outer = rel->lateral_relids;
2399 
2400  /*
2401  * The result is considered unordered unless ORDINALITY was used, in which
2402  * case it is ordered by the ordinal column (the last one). See if we
2403  * care, by checking for uses of that Var in equivalence classes.
2404  */
2405  if (rte->funcordinality)
2406  {
2407  AttrNumber ordattno = rel->max_attr;
2408  Var *var = NULL;
2409  ListCell *lc;
2410 
2411  /*
2412  * Is there a Var for it in rel's targetlist? If not, the query did
2413  * not reference the ordinality column, or at least not in any way
2414  * that would be interesting for sorting.
2415  */
2416  foreach(lc, rel->reltarget->exprs)
2417  {
2418  Var *node = (Var *) lfirst(lc);
2419 
2420  /* checking varno/varlevelsup is just paranoia */
2421  if (IsA(node, Var) &&
2422  node->varattno == ordattno &&
2423  node->varno == rel->relid &&
2424  node->varlevelsup == 0)
2425  {
2426  var = node;
2427  break;
2428  }
2429  }
2430 
2431  /*
2432  * Try to build pathkeys for this Var with int8 sorting. We tell
2433  * build_expression_pathkey not to build any new equivalence class; if
2434  * the Var isn't already mentioned in some EC, it means that nothing
2435  * cares about the ordering.
2436  */
2437  if (var)
2438  pathkeys = build_expression_pathkey(root,
2439  (Expr *) var,
2440  NULL, /* below outer joins */
2441  Int8LessOperator,
2442  rel->relids,
2443  false);
2444  }
2445 
2446  /* Generate appropriate path */
2447  add_path(rel, create_functionscan_path(root, rel,
2448  pathkeys, required_outer));
2449 }
#define NIL
Definition: pg_list.h:65
#define IsA(nodeptr, _type_)
Definition: nodes.h:580
List * build_expression_pathkey(PlannerInfo *root, Expr *expr, Relids nullable_relids, Oid opno, Relids rel, bool create_it)
Definition: pathkeys.c:782
Index varlevelsup
Definition: primnodes.h:191
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
AttrNumber varattno
Definition: primnodes.h:186
bool funcordinality
Definition: parsenodes.h:1064
Definition: primnodes.h:181
Path * create_functionscan_path(PlannerInfo *root, RelOptInfo *rel, List *pathkeys, Relids required_outer)
Definition: pathnode.c:1912
Relids lateral_relids
Definition: pathnodes.h:690
Relids relids
Definition: pathnodes.h:665
Index relid
Definition: pathnodes.h:693
Index varno
Definition: primnodes.h:184
List * exprs
Definition: pathnodes.h:1074
#define lfirst(lc)
Definition: pg_list.h:190
AttrNumber max_attr
Definition: pathnodes.h:697
Definition: pg_list.h:50
struct PathTarget * reltarget
Definition: pathnodes.h:676
int16 AttrNumber
Definition: attnum.h:21

◆ set_namedtuplestore_pathlist()

static void set_namedtuplestore_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 2566 of file allpaths.c.

References add_path(), create_namedtuplestorescan_path(), RelOptInfo::lateral_relids, set_cheapest(), and set_namedtuplestore_size_estimates().

Referenced by set_rel_size().

2568 {
2569  Relids required_outer;
2570 
2571  /* Mark rel with estimated output rows, width, etc */
2573 
2574  /*
2575  * We don't support pushing join clauses into the quals of a tuplestore
2576  * scan, but it could still have required parameterization due to LATERAL
2577  * refs in its tlist.
2578  */
2579  required_outer = rel->lateral_relids;
2580 
2581  /* Generate appropriate path */
2582  add_path(rel, create_namedtuplestorescan_path(root, rel, required_outer));
2583 
2584  /* Select cheapest path (pretty easy in this case...) */
2585  set_cheapest(rel);
2586 }
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
Relids lateral_relids
Definition: pathnodes.h:690
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:244
void set_namedtuplestore_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5344
Path * create_namedtuplestorescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2015

◆ set_plain_rel_pathlist()

static void set_plain_rel_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 766 of file allpaths.c.

References add_path(), RelOptInfo::consider_parallel, create_index_paths(), create_plain_partial_paths(), create_seqscan_path(), create_tidscan_paths(), and RelOptInfo::lateral_relids.

Referenced by set_rel_pathlist().

767 {
768  Relids required_outer;
769 
770  /*
771  * We don't support pushing join clauses into the quals of a seqscan, but
772  * it could still have required parameterization due to LATERAL refs in
773  * its tlist.
774  */
775  required_outer = rel->lateral_relids;
776 
777  /* Consider sequential scan */
778  add_path(rel, create_seqscan_path(root, rel, required_outer, 0));
779 
780  /* If appropriate, consider parallel sequential scan */
781  if (rel->consider_parallel && required_outer == NULL)
782  create_plain_partial_paths(root, rel);
783 
784  /* Consider index scans */
785  create_index_paths(root, rel);
786 
787  /* Consider TID scans */
788  create_tidscan_paths(root, rel);
789 }
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
void create_index_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:232
Relids lateral_relids
Definition: pathnodes.h:690
void create_tidscan_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: tidpath.c:385
bool consider_parallel
Definition: pathnodes.h:673
static void create_plain_partial_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:796
Path * create_seqscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer, int parallel_workers)
Definition: pathnode.c:929

◆ set_plain_rel_size()

static void set_plain_rel_size ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 574 of file allpaths.c.

References check_index_predicates(), and set_baserel_size_estimates().

Referenced by set_rel_size().

575 {
576  /*
577  * Test any partial indexes of rel for applicability. We must do this
578  * first since partial unique indexes can affect size estimates.
579  */
580  check_index_predicates(root, rel);
581 
582  /* Mark rel with estimated output rows, width, etc */
583  set_baserel_size_estimates(root, rel);
584 }
void check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:3395
void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:4627

◆ set_rel_consider_parallel()

static void set_rel_consider_parallel ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 591 of file allpaths.c.

References TableSampleClause::args, Assert, RelOptInfo::baserestrictinfo, castNode, RelOptInfo::consider_parallel, PathTarget::exprs, RelOptInfo::fdwroutine, func_parallel(), RangeTblEntry::functions, get_rel_persistence(), PlannerInfo::glob, is_parallel_safe(), IS_SIMPLE_REL, FdwRoutine::IsForeignScanParallelSafe, limit_needed(), PlannerGlobal::parallelModeOK, RangeTblEntry::relid, RangeTblEntry::relkind, RelOptInfo::reltarget, RTE_CTE, RTE_FUNCTION, RTE_JOIN, RTE_NAMEDTUPLESTORE, RTE_RELATION, RTE_RESULT, RTE_SUBQUERY, RTE_TABLEFUNC, RTE_VALUES, RangeTblEntry::rtekind, RangeTblEntry::subquery, RangeTblEntry::tablesample, TableSampleClause::tsmhandler, and RangeTblEntry::values_lists.

Referenced by set_append_rel_size(), and set_base_rel_sizes().

593 {
594  /*
595  * The flag has previously been initialized to false, so we can just
596  * return if it becomes clear that we can't safely set it.
597  */
598  Assert(!rel->consider_parallel);
599 
600  /* Don't call this if parallelism is disallowed for the entire query. */
601  Assert(root->glob->parallelModeOK);
602 
603  /* This should only be called for baserels and appendrel children. */
604  Assert(IS_SIMPLE_REL(rel));
605 
606  /* Assorted checks based on rtekind. */
607  switch (rte->rtekind)
608  {
609  case RTE_RELATION:
610 
611  /*
612  * Currently, parallel workers can't access the leader's temporary
613  * tables. We could possibly relax this if we wrote all of its
614  * local buffers at the start of the query and made no changes
615  * thereafter (maybe we could allow hint bit changes), and if we
616  * taught the workers to read them. Writing a large number of
617  * temporary buffers could be expensive, though, and we don't have
618  * the rest of the necessary infrastructure right now anyway. So
619  * for now, bail out if we see a temporary table.
620  */
621  if (get_rel_persistence(rte->relid) == RELPERSISTENCE_TEMP)
622  return;
623 
624  /*
625  * Table sampling can be pushed down to workers if the sample
626  * function and its arguments are safe.
627  */
628  if (rte->tablesample != NULL)
629  {
630  char proparallel = func_parallel(rte->tablesample->tsmhandler);
631 
632  if (proparallel != PROPARALLEL_SAFE)
633  return;
634  if (!is_parallel_safe(root, (Node *) rte->tablesample->args))
635  return;
636  }
637 
638  /*
639  * Ask FDWs whether they can support performing a ForeignScan
640  * within a worker. Most often, the answer will be no. For
641  * example, if the nature of the FDW is such that it opens a TCP
642  * connection with a remote server, each parallel worker would end
643  * up with a separate connection, and these connections might not
644  * be appropriately coordinated between workers and the leader.
645  */
646  if (rte->relkind == RELKIND_FOREIGN_TABLE)
647  {
648  Assert(rel->fdwroutine);
650  return;
651  if (!rel->fdwroutine->IsForeignScanParallelSafe(root, rel, rte))
652  return;
653  }
654 
655  /*
656  * There are additional considerations for appendrels, which we'll
657  * deal with in set_append_rel_size and set_append_rel_pathlist.
658  * For now, just set consider_parallel based on the rel's own
659  * quals and targetlist.
660  */
661  break;
662 
663  case RTE_SUBQUERY:
664 
665  /*
666  * There's no intrinsic problem with scanning a subquery-in-FROM
667  * (as distinct from a SubPlan or InitPlan) in a parallel worker.
668  * If the subquery doesn't happen to have any parallel-safe paths,
669  * then flagging it as consider_parallel won't change anything,
670  * but that's true for plain tables, too. We must set
671  * consider_parallel based on the rel's own quals and targetlist,
672  * so that if a subquery path is parallel-safe but the quals and
673  * projection we're sticking onto it are not, we correctly mark
674  * the SubqueryScanPath as not parallel-safe. (Note that
675  * set_subquery_pathlist() might push some of these quals down
676  * into the subquery itself, but that doesn't change anything.)
677  *
678  * We can't push sub-select containing LIMIT/OFFSET to workers as
679  * there is no guarantee that the row order will be fully
680  * deterministic, and applying LIMIT/OFFSET will lead to
681  * inconsistent results at the top-level. (In some cases, where
682  * the result is ordered, we could relax this restriction. But it
683  * doesn't currently seem worth expending extra effort to do so.)
684  */
685  {
686  Query *subquery = castNode(Query, rte->subquery);
687 
688  if (limit_needed(subquery))
689  return;
690  }
691  break;
692 
693  case RTE_JOIN:
694  /* Shouldn't happen; we're only considering baserels here. */
695  Assert(false);
696  return;
697 
698  case RTE_FUNCTION:
699  /* Check for parallel-restricted functions. */
700  if (!is_parallel_safe(root, (Node *) rte->functions))
701  return;
702  break;
703 
704  case RTE_TABLEFUNC:
705  /* not parallel safe */
706  return;
707 
708  case RTE_VALUES:
709  /* Check for parallel-restricted functions. */
710  if (!is_parallel_safe(root, (Node *) rte->values_lists))
711  return;
712  break;
713 
714  case RTE_CTE:
715 
716  /*
717  * CTE tuplestores aren't shared among parallel workers, so we
718  * force all CTE scans to happen in the leader. Also, populating
719  * the CTE would require executing a subplan that's not available
720  * in the worker, might be parallel-restricted, and must get
721  * executed only once.
722  */
723  return;
724 
725  case RTE_NAMEDTUPLESTORE:
726 
727  /*
728  * tuplestore cannot be shared, at least without more
729  * infrastructure to support that.
730  */
731  return;
732 
733  case RTE_RESULT:
734  /* RESULT RTEs, in themselves, are no problem. */
735  break;
736  }
737 
738  /*
739  * If there's anything in baserestrictinfo that's parallel-restricted, we
740  * give up on parallelizing access to this relation. We could consider
741  * instead postponing application of the restricted quals until we're
742  * above all the parallelism in the plan tree, but it's not clear that
743  * that would be a win in very many cases, and it might be tricky to make
744  * outer join clauses work correctly. It would likely break equivalence
745  * classes, too.
746  */
747  if (!is_parallel_safe(root, (Node *) rel->baserestrictinfo))
748  return;
749 
750  /*
751  * Likewise, if the relation's outputs are not parallel-safe, give up.
752  * (Usually, they're just Vars, but sometimes they're not.)
753  */
754  if (!is_parallel_safe(root, (Node *) rel->reltarget->exprs))
755  return;
756 
757  /* We have a winner. */
758  rel->consider_parallel = true;
759 }
#define castNode(_type_, nodeptr)
Definition: nodes.h:598
List * baserestrictinfo
Definition: pathnodes.h:727
bool limit_needed(Query *parse)
Definition: planner.c:3012
Definition: nodes.h:529
List * values_lists
Definition: parsenodes.h:1074
#define IS_SIMPLE_REL(rel)
Definition: pathnodes.h:638
bool is_parallel_safe(PlannerInfo *root, Node *node)
Definition: clauses.c:856
IsForeignScanParallelSafe_function IsForeignScanParallelSafe
Definition: fdwapi.h:240
bool parallelModeOK
Definition: pathnodes.h:143
PlannerGlobal * glob
Definition: pathnodes.h:181
struct FdwRoutine * fdwroutine
Definition: pathnodes.h:718
List * exprs
Definition: pathnodes.h:1074
#define Assert(condition)
Definition: c.h:738
List * functions
Definition: parsenodes.h:1063
char func_parallel(Oid funcid)
Definition: lsyscache.c:1711
bool consider_parallel
Definition: pathnodes.h:673
char get_rel_persistence(Oid relid)
Definition: lsyscache.c:1990
RTEKind rtekind
Definition: parsenodes.h:976
Query * subquery
Definition: parsenodes.h:1011
struct PathTarget * reltarget
Definition: pathnodes.h:676
struct TableSampleClause * tablesample
Definition: parsenodes.h:1006

◆ set_rel_pathlist()

static void set_rel_pathlist ( PlannerInfo root,
RelOptInfo rel,
Index  rti,
RangeTblEntry rte 
)
static

Definition at line 470 of file allpaths.c.

References bms_membership(), BMS_SINGLETON, elog, ERROR, generate_useful_gather_paths(), RangeTblEntry::inh, IS_DUMMY_REL, RangeTblEntry::relkind, RELOPT_BASEREL, RTE_CTE, RTE_FUNCTION, RTE_NAMEDTUPLESTORE, RTE_RELATION, RTE_RESULT, RTE_SUBQUERY, RTE_TABLEFUNC, RTE_VALUES, RelOptInfo::rtekind, set_append_rel_pathlist(), set_cheapest(), set_foreign_pathlist(), set_function_pathlist(), set_plain_rel_pathlist(), set_rel_pathlist_hook, set_tablefunc_pathlist(), set_tablesample_rel_pathlist(), set_values_pathlist(), and RangeTblEntry::tablesample.

Referenced by set_append_rel_pathlist(), and set_base_rel_pathlists().

472 {
473  if (IS_DUMMY_REL(rel))
474  {
475  /* We already proved the relation empty, so nothing more to do */
476  }
477  else if (rte->inh)
478  {
479  /* It's an "append relation", process accordingly */
480  set_append_rel_pathlist(root, rel, rti, rte);
481  }
482  else
483  {
484  switch (rel->rtekind)
485  {
486  case RTE_RELATION:
487  if (rte->relkind == RELKIND_FOREIGN_TABLE)
488  {
489  /* Foreign table */
490  set_foreign_pathlist(root, rel, rte);
491  }
492  else if (rte->tablesample != NULL)
493  {
494  /* Sampled relation */
495  set_tablesample_rel_pathlist(root, rel, rte);
496  }
497  else
498  {
499  /* Plain relation */
500  set_plain_rel_pathlist(root, rel, rte);
501  }
502  break;
503  case RTE_SUBQUERY:
504  /* Subquery --- fully handled during set_rel_size */
505  break;
506  case RTE_FUNCTION:
507  /* RangeFunction */
508  set_function_pathlist(root, rel, rte);
509  break;
510  case RTE_TABLEFUNC:
511  /* Table Function */
512  set_tablefunc_pathlist(root, rel, rte);
513  break;
514  case RTE_VALUES:
515  /* Values list */
516  set_values_pathlist(root, rel, rte);
517  break;
518  case RTE_CTE:
519  /* CTE reference --- fully handled during set_rel_size */
520  break;
521  case RTE_NAMEDTUPLESTORE:
522  /* tuplestore reference --- fully handled during set_rel_size */
523  break;
524  case RTE_RESULT:
525  /* simple Result --- fully handled during set_rel_size */
526  break;
527  default:
528  elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
529  break;
530  }
531  }
532 
533  /*
534  * Allow a plugin to editorialize on the set of Paths for this base
535  * relation. It could add new paths (such as CustomPaths) by calling
536  * add_path(), or add_partial_path() if parallel aware. It could also
537  * delete or modify paths added by the core code.
538  */
540  (*set_rel_pathlist_hook) (root, rel, rti, rte);
541 
542  /*
543  * If this is a baserel, we should normally consider gathering any partial
544  * paths we may have created for it. We have to do this after calling the
545  * set_rel_pathlist_hook, else it cannot add partial paths to be included
546  * here.
547  *
548  * However, if this is an inheritance child, skip it. Otherwise, we could
549  * end up with a very large number of gather nodes, each trying to grab
550  * its own pool of workers. Instead, we'll consider gathering partial
551  * paths for the parent appendrel.
552  *
553  * Also, if this is the topmost scan/join rel (that is, the only baserel),
554  * we postpone gathering until the final scan/join targetlist is available
555  * (see grouping_planner).
556  */
557  if (rel->reloptkind == RELOPT_BASEREL &&
558  bms_membership(root->all_baserels) != BMS_SINGLETON)
559  generate_useful_gather_paths(root, rel, false);
560 
561  /* Now find the cheapest of the paths for this rel */
562  set_cheapest(rel);
563 
564 #ifdef OPTIMIZER_DEBUG
565  debug_print_rel(root, rel);
566 #endif
567 }
set_rel_pathlist_hook_type set_rel_pathlist_hook
Definition: allpaths.c:68
void generate_useful_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
Definition: allpaths.c:2816
#define ERROR
Definition: elog.h:43
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1418
static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:1221
static void set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:924
static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:766
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:244
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:672
RTEKind rtekind
Definition: pathnodes.h:695
static void set_tablesample_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:856
static void set_tablefunc_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2476
#define elog(elevel,...)
Definition: elog.h:214
static void set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2388
static void set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2456
struct TableSampleClause * tablesample
Definition: parsenodes.h:1006

◆ set_rel_size()

static void set_rel_size ( PlannerInfo root,
RelOptInfo rel,
Index  rti,
RangeTblEntry rte 
)
static

Definition at line 361 of file allpaths.c.

References Assert, elog, ERROR, RangeTblEntry::inh, IS_DUMMY_REL, relation_excluded_by_constraints(), RangeTblEntry::relkind, RELOPT_BASEREL, RelOptInfo::reloptkind, RelOptInfo::rows, RTE_CTE, RTE_FUNCTION, RTE_NAMEDTUPLESTORE, RTE_RELATION, RTE_RESULT, RTE_SUBQUERY, RTE_TABLEFUNC, RTE_VALUES, RelOptInfo::rtekind, RangeTblEntry::self_reference, set_append_rel_size(), set_cte_pathlist(), set_dummy_rel_pathlist(), set_foreign_size(), set_function_size_estimates(), set_namedtuplestore_pathlist(), set_plain_rel_size(), set_result_pathlist(), set_subquery_pathlist(), set_tablefunc_size_estimates(), set_tablesample_rel_size(), set_values_size_estimates(), set_worktable_pathlist(), and RangeTblEntry::tablesample.

Referenced by set_append_rel_size(), and set_base_rel_sizes().

363 {
364  if (rel->reloptkind == RELOPT_BASEREL &&
365  relation_excluded_by_constraints(root, rel, rte))
366  {
367  /*
368  * We proved we don't need to scan the rel via constraint exclusion,
369  * so set up a single dummy path for it. Here we only check this for
370  * regular baserels; if it's an otherrel, CE was already checked in
371  * set_append_rel_size().
372  *
373  * In this case, we go ahead and set up the relation's path right away
374  * instead of leaving it for set_rel_pathlist to do. This is because
375  * we don't have a convention for marking a rel as dummy except by
376  * assigning a dummy path to it.
377  */
379  }
380  else if (rte->inh)
381  {
382  /* It's an "append relation", process accordingly */
383  set_append_rel_size(root, rel, rti, rte);
384  }
385  else
386  {
387  switch (rel->rtekind)
388  {
389  case RTE_RELATION:
390  if (rte->relkind == RELKIND_FOREIGN_TABLE)
391  {
392  /* Foreign table */
393  set_foreign_size(root, rel, rte);
394  }
395  else if (rte->relkind == RELKIND_PARTITIONED_TABLE)
396  {
397  /*
398  * We could get here if asked to scan a partitioned table
399  * with ONLY. In that case we shouldn't scan any of the
400  * partitions, so mark it as a dummy rel.
401  */
403  }
404  else if (rte->tablesample != NULL)
405  {
406  /* Sampled relation */
407  set_tablesample_rel_size(root, rel, rte);
408  }
409  else
410  {
411  /* Plain relation */
412  set_plain_rel_size(root, rel, rte);
413  }
414  break;
415  case RTE_SUBQUERY:
416 
417  /*
418  * Subqueries don't support making a choice between
419  * parameterized and unparameterized paths, so just go ahead
420  * and build their paths immediately.
421  */
422  set_subquery_pathlist(root, rel, rti, rte);
423  break;
424  case RTE_FUNCTION:
425  set_function_size_estimates(root, rel);
426  break;
427  case RTE_TABLEFUNC:
428  set_tablefunc_size_estimates(root, rel);
429  break;
430  case RTE_VALUES:
431  set_values_size_estimates(root, rel);
432  break;
433  case RTE_CTE:
434 
435  /*
436  * CTEs don't support making a choice between parameterized
437  * and unparameterized paths, so just go ahead and build their
438  * paths immediately.
439  */
440  if (rte->self_reference)
441  set_worktable_pathlist(root, rel, rte);
442  else
443  set_cte_pathlist(root, rel, rte);
444  break;
445  case RTE_NAMEDTUPLESTORE:
446  /* Might as well just build the path immediately */
447  set_namedtuplestore_pathlist(root, rel, rte);
448  break;
449  case RTE_RESULT:
450  /* Might as well just build the path immediately */
451  set_result_pathlist(root, rel, rte);
452  break;
453  default:
454  elog(ERROR, "unexpected rtekind: %d", (int) rel->rtekind);
455  break;
456  }
457  }
458 
459  /*
460  * We insist that all non-dummy rels have a nonzero rowcount estimate.
461  */
462  Assert(rel->rows > 0 || IS_DUMMY_REL(rel));
463 }
RelOptKind reloptkind
Definition: pathnodes.h:662
static void set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2500
static void set_foreign_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:904
bool relation_excluded_by_constraints(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: plancat.c:1387
static void set_namedtuplestore_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2566
static void set_append_rel_size(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:942
static void set_result_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2596
#define ERROR
Definition: elog.h:43
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1418
static void set_dummy_rel_pathlist(RelOptInfo *rel)
Definition: allpaths.c:2125
static void set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti, RangeTblEntry *rte)
Definition: allpaths.c:2184
static void set_tablesample_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:816
bool self_reference
Definition: parsenodes.h:1081
RTEKind rtekind
Definition: pathnodes.h:695
double rows
Definition: pathnodes.h:668
#define Assert(condition)
Definition: c.h:738
void set_values_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5275
static void set_plain_rel_size(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:574
#define elog(elevel,...)
Definition: elog.h:214
void set_tablefunc_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5253
void set_function_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5215
struct TableSampleClause * tablesample
Definition: parsenodes.h:1006
static void set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
Definition: allpaths.c:2626

◆ set_result_pathlist()

static void set_result_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 2596 of file allpaths.c.

References add_path(), create_resultscan_path(), RelOptInfo::lateral_relids, set_cheapest(), and set_result_size_estimates().

Referenced by set_rel_size().

2598 {
2599  Relids required_outer;
2600 
2601  /* Mark rel with estimated output rows, width, etc */
2602  set_result_size_estimates(root, rel);
2603 
2604  /*
2605  * We don't support pushing join clauses into the quals of a Result scan,
2606  * but it could still have required parameterization due to LATERAL refs
2607  * in its tlist.
2608  */
2609  required_outer = rel->lateral_relids;
2610 
2611  /* Generate appropriate path */
2612  add_path(rel, create_resultscan_path(root, rel, required_outer));
2613 
2614  /* Select cheapest path (pretty easy in this case...) */
2615  set_cheapest(rel);
2616 }
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
Path * create_resultscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2041
void set_result_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5377
Relids lateral_relids
Definition: pathnodes.h:690
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:244

◆ set_subquery_pathlist()

static void set_subquery_pathlist ( PlannerInfo root,
RelOptInfo rel,
Index  rti,
RangeTblEntry rte 
)
static

Definition at line 2184 of file allpaths.c.

References add_partial_path(), add_path(), Assert, RelOptInfo::baserestrictinfo, bms_is_empty(), RestrictInfo::clause, RelOptInfo::consider_parallel, convert_subquery_pathkeys(), copyObject, create_subqueryscan_path(), Query::distinctClause, fetch_upper_rel(), PlannerInfo::glob, Query::groupClause, Query::groupingSets, has_multiple_baserels(), Query::hasAggs, Query::havingQual, IS_DUMMY_REL, lappend(), RelOptInfo::lateral_relids, lfirst, list_length(), make_tlist_from_pathtarget(), NIL, palloc0(), parse(), PlannerInfo::parse, RelOptInfo::partial_pathlist, Path::pathkeys, RelOptInfo::pathlist, Path::pathtarget, pfree(), PlannerInfo::plan_params, RestrictInfo::pseudoconstant, qual_is_pushdown_safe(), remove_unused_subquery_outputs(), RangeTblEntry::security_barrier, set_dummy_rel_pathlist(), set_subquery_size_estimates(), Query::sortClause, subpath(), RelOptInfo::subplan_params, RangeTblEntry::subquery, subquery_is_pushdown_safe(), subquery_planner(), subquery_push_qual(), RelOptInfo::subroot, Query::targetList, PlannerInfo::tuple_fraction, pushdown_safety_info::unsafeColumns, pushdown_safety_info::unsafeLeaky, and UPPERREL_FINAL.

Referenced by set_rel_size().

2186 {
2187  Query *parse = root->parse;
2188  Query *subquery = rte->subquery;
2189  Relids required_outer;
2190  pushdown_safety_info safetyInfo;
2191  double tuple_fraction;
2192  RelOptInfo *sub_final_rel;
2193  ListCell *lc;
2194 
2195  /*
2196  * Must copy the Query so that planning doesn't mess up the RTE contents
2197  * (really really need to fix the planner to not scribble on its input,
2198  * someday ... but see remove_unused_subquery_outputs to start with).
2199  */
2200  subquery = copyObject(subquery);
2201 
2202  /*
2203  * If it's a LATERAL subquery, it might contain some Vars of the current
2204  * query level, requiring it to be treated as parameterized, even though
2205  * we don't support pushing down join quals into subqueries.
2206  */
2207  required_outer = rel->lateral_relids;
2208 
2209  /*
2210  * Zero out result area for subquery_is_pushdown_safe, so that it can set
2211  * flags as needed while recursing. In particular, we need a workspace
2212  * for keeping track of unsafe-to-reference columns. unsafeColumns[i]
2213  * will be set true if we find that output column i of the subquery is
2214  * unsafe to use in a pushed-down qual.
2215  */
2216  memset(&safetyInfo, 0, sizeof(safetyInfo));
2217  safetyInfo.unsafeColumns = (bool *)
2218  palloc0((list_length(subquery->targetList) + 1) * sizeof(bool));
2219 
2220  /*
2221  * If the subquery has the "security_barrier" flag, it means the subquery
2222  * originated from a view that must enforce row level security. Then we
2223  * must not push down quals that contain leaky functions. (Ideally this
2224  * would be checked inside subquery_is_pushdown_safe, but since we don't
2225  * currently pass the RTE to that function, we must do it here.)
2226  */
2227  safetyInfo.unsafeLeaky = rte->security_barrier;
2228 
2229  /*
2230  * If there are any restriction clauses that have been attached to the
2231  * subquery relation, consider pushing them down to become WHERE or HAVING
2232  * quals of the subquery itself. This transformation is useful because it
2233  * may allow us to generate a better plan for the subquery than evaluating
2234  * all the subquery output rows and then filtering them.
2235  *
2236  * There are several cases where we cannot push down clauses. Restrictions
2237  * involving the subquery are checked by subquery_is_pushdown_safe().
2238  * Restrictions on individual clauses are checked by
2239  * qual_is_pushdown_safe(). Also, we don't want to push down
2240  * pseudoconstant clauses; better to have the gating node above the
2241  * subquery.
2242  *
2243  * Non-pushed-down clauses will get evaluated as qpquals of the
2244  * SubqueryScan node.
2245  *
2246  * XXX Are there any cases where we want to make a policy decision not to
2247  * push down a pushable qual, because it'd result in a worse plan?
2248  */
2249  if (rel->baserestrictinfo != NIL &&
2250  subquery_is_pushdown_safe(subquery, subquery, &safetyInfo))
2251  {
2252  /* OK to consider pushing down individual quals */
2253  List *upperrestrictlist = NIL;
2254  ListCell *l;
2255 
2256  foreach(l, rel->baserestrictinfo)
2257  {
2258  RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
2259  Node *clause = (Node *) rinfo->clause;
2260 
2261  if (!rinfo->pseudoconstant &&
2262  qual_is_pushdown_safe(subquery, rti, clause, &safetyInfo))
2263  {
2264  /* Push it down */
2265  subquery_push_qual(subquery, rte, rti, clause);
2266  }
2267  else
2268  {
2269  /* Keep it in the upper query */
2270  upperrestrictlist = lappend(upperrestrictlist, rinfo);
2271  }
2272  }
2273  rel->baserestrictinfo = upperrestrictlist;
2274  /* We don't bother recomputing baserestrict_min_security */
2275  }
2276 
2277  pfree(safetyInfo.unsafeColumns);
2278 
2279  /*
2280  * The upper query might not use all the subquery's output columns; if
2281  * not, we can simplify.
2282  */
2283  remove_unused_subquery_outputs(subquery, rel);
2284 
2285  /*
2286  * We can safely pass the outer tuple_fraction down to the subquery if the
2287  * outer level has no joining, aggregation, or sorting to do. Otherwise
2288  * we'd better tell the subquery to plan for full retrieval. (XXX This
2289  * could probably be made more intelligent ...)
2290  */
2291  if (parse->hasAggs ||
2292  parse->groupClause ||
2293  parse->groupingSets ||
2294  parse->havingQual ||
2295  parse->distinctClause ||
2296  parse->sortClause ||
2297  has_multiple_baserels(root))
2298  tuple_fraction = 0.0; /* default case */
2299  else
2300  tuple_fraction = root->tuple_fraction;
2301 
2302  /* plan_params should not be in use in current query level */
2303  Assert(root->plan_params == NIL);
2304 
2305  /* Generate a subroot and Paths for the subquery */
2306  rel->subroot = subquery_planner(root->glob, subquery,
2307  root,
2308  false, tuple_fraction);
2309 
2310  /* Isolate the params needed by this specific subplan */
2311  rel->subplan_params = root->plan_params;
2312  root->plan_params = NIL;
2313 
2314  /*
2315  * It's possible that constraint exclusion proved the subquery empty. If
2316  * so, it's desirable to produce an unadorned dummy path so that we will
2317  * recognize appropriate optimizations at this query level.
2318  */
2319  sub_final_rel = fetch_upper_rel(rel->subroot, UPPERREL_FINAL, NULL);
2320 
2321  if (IS_DUMMY_REL(sub_final_rel))
2322  {
2324  return;
2325  }
2326 
2327  /*
2328  * Mark rel with estimated output rows, width, etc. Note that we have to
2329  * do this before generating outer-query paths, else cost_subqueryscan is
2330  * not happy.
2331  */
2332  set_subquery_size_estimates(root, rel);
2333 
2334  /*
2335  * For each Path that subquery_planner produced, make a SubqueryScanPath
2336  * in the outer query.
2337  */
2338  foreach(lc, sub_final_rel->pathlist)
2339  {
2340  Path *subpath = (Path *) lfirst(lc);
2341  List *pathkeys;
2342 
2343  /* Convert subpath's pathkeys to outer representation */
2344  pathkeys = convert_subquery_pathkeys(root,
2345  rel,
2346  subpath->pathkeys,
2348 
2349  /* Generate outer path using this subpath */
2350  add_path(rel, (Path *)
2351  create_subqueryscan_path(root, rel, subpath,
2352  pathkeys, required_outer));
2353  }
2354 
2355  /* If outer rel allows parallelism, do same for partial paths. */
2356  if (rel->consider_parallel && bms_is_empty(required_outer))
2357  {
2358  /* If consider_parallel is false, there should be no partial paths. */
2359  Assert(sub_final_rel->consider_parallel ||
2360  sub_final_rel->partial_pathlist == NIL);
2361 
2362  /* Same for partial paths. */
2363  foreach(lc, sub_final_rel->partial_pathlist)
2364  {
2365  Path *subpath = (Path *) lfirst(lc);
2366  List *pathkeys;
2367 
2368  /* Convert subpath's pathkeys to outer representation */
2369  pathkeys = convert_subquery_pathkeys(root,
2370  rel,
2371  subpath->pathkeys,
2373 
2374  /* Generate outer path using this subpath */
2375  add_partial_path(rel, (Path *)
2376  create_subqueryscan_path(root, rel, subpath,
2377  pathkeys,
2378  required_outer));
2379  }
2380  }
2381 }
void set_subquery_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:5135
#define NIL
Definition: pg_list.h:65
PathTarget * pathtarget
Definition: pathnodes.h:1145
Query * parse
Definition: pathnodes.h:179
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
SubqueryScanPath * create_subqueryscan_path(PlannerInfo *root, RelOptInfo *rel, Path *subpath, List *pathkeys, Relids required_outer)
Definition: pathnode.c:1884
List * plan_params
Definition: pathnodes.h:193
List * sortClause
Definition: parsenodes.h:158
List * baserestrictinfo
Definition: pathnodes.h:727
bool hasAggs
Definition: parsenodes.h:125
bool pseudoconstant
Definition: pathnodes.h:1993
List * groupingSets
Definition: parsenodes.h:150
Definition: nodes.h:529
List * partial_pathlist
Definition: pathnodes.h:681
List * make_tlist_from_pathtarget(PathTarget *target)
Definition: tlist.c:639
bool * unsafeColumns
Definition: allpaths.c:56
List * targetList
Definition: parsenodes.h:140
PlannerInfo * subroot
Definition: pathnodes.h:709
Relids lateral_relids
Definition: pathnodes.h:690
double tuple_fraction
Definition: pathnodes.h:336
void pfree(void *pointer)
Definition: mcxt.c:1056
List * distinctClause
Definition: parsenodes.h:156
#define IS_DUMMY_REL(r)
Definition: pathnodes.h:1418
RelOptInfo * fetch_upper_rel(PlannerInfo *root, UpperRelationKind kind, Relids relids)
Definition: relnode.c:1192
static void set_dummy_rel_pathlist(RelOptInfo *rel)
Definition: allpaths.c:2125
List * convert_subquery_pathkeys(PlannerInfo *root, RelOptInfo *rel, List *subquery_pathkeys, List *subquery_tlist)
Definition: pathkeys.c:838
PlannerGlobal * glob
Definition: pathnodes.h:181
static void remove_unused_subquery_outputs(Query *subquery, RelOptInfo *rel)
Definition: allpaths.c:3653
List * lappend(List *list, void *datum)
Definition: list.c:321
Expr * clause
Definition: pathnodes.h:1985
bool bms_is_empty(const Bitmapset *a)
Definition: bitmapset.c:701
static bool qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3482
void * palloc0(Size size)
Definition: mcxt.c:980
bool security_barrier
Definition: parsenodes.h:1012
List * pathkeys
Definition: pathnodes.h:1158
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
static bool has_multiple_baserels(PlannerInfo *root)
Definition: allpaths.c:2151
static void subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:3559
static int list_length(const List *l)
Definition: pg_list.h:169
bool consider_parallel
Definition: pathnodes.h:673
static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3220
Query * subquery
Definition: parsenodes.h:1011
List * groupClause
Definition: parsenodes.h:148
void add_partial_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:749
List * pathlist
Definition: pathnodes.h:679
#define copyObject(obj)
Definition: nodes.h:645
Node * havingQual
Definition: parsenodes.h:152
Definition: pg_list.h:50
List * subplan_params
Definition: pathnodes.h:710
PlannerInfo * subquery_planner(PlannerGlobal *glob, Query *parse, PlannerInfo *parent_root, bool hasRecursion, double tuple_fraction)
Definition: planner.c:597
Datum subpath(PG_FUNCTION_ARGS)
Definition: ltree_op.c:241
static struct subre * parse(struct vars *, int, int, struct state *, struct state *)
Definition: regcomp.c:648
unsigned char bool
Definition: c.h:317

◆ set_tablefunc_pathlist()

static void set_tablefunc_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 2476 of file allpaths.c.

References add_path(), create_tablefuncscan_path(), and RelOptInfo::lateral_relids.

Referenced by set_rel_pathlist().

2477 {
2478  Relids required_outer;
2479 
2480  /*
2481  * We don't support pushing join clauses into the quals of a tablefunc
2482  * scan, but it could still have required parameterization due to LATERAL
2483  * refs in the function expression.
2484  */
2485  required_outer = rel->lateral_relids;
2486 
2487  /* Generate appropriate path */
2488  add_path(rel, create_tablefuncscan_path(root, rel,
2489  required_outer));
2490 }
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
Relids lateral_relids
Definition: pathnodes.h:690
Path * create_tablefuncscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1938

◆ set_tablesample_rel_pathlist()

static void set_tablesample_rel_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 856 of file allpaths.c.

References add_path(), PlannerInfo::all_baserels, bms_membership(), BMS_SINGLETON, create_material_path(), create_samplescan_path(), GetTsmRoutine(), RelOptInfo::lateral_relids, PlannerInfo::query_level, TsmRoutine::repeatable_across_scans, RangeTblEntry::tablesample, and TableSampleClause::tsmhandler.

Referenced by set_rel_pathlist().

857 {
858  Relids required_outer;
859  Path *path;
860 
861  /*
862  * We don't support pushing join clauses into the quals of a samplescan,
863  * but it could still have required parameterization due to LATERAL refs
864  * in its tlist or TABLESAMPLE arguments.
865  */
866  required_outer = rel->lateral_relids;
867 
868  /* Consider sampled scan */
869  path = create_samplescan_path(root, rel, required_outer);
870 
871  /*
872  * If the sampling method does not support repeatable scans, we must avoid
873  * plans that would scan the rel multiple times. Ideally, we'd simply
874  * avoid putting the rel on the inside of a nestloop join; but adding such
875  * a consideration to the planner seems like a great deal of complication
876  * to support an uncommon usage of second-rate sampling methods. Instead,
877  * if there is a risk that the query might perform an unsafe join, just
878  * wrap the SampleScan in a Materialize node. We can check for joins by
879  * counting the membership of all_baserels (note that this correctly
880  * counts inheritance trees as single rels). If we're inside a subquery,
881  * we can't easily check whether a join might occur in the outer query, so
882  * just assume one is possible.
883  *
884  * GetTsmRoutine is relatively expensive compared to the other tests here,
885  * so check repeatable_across_scans last, even though that's a bit odd.
886  */
887  if ((root->query_level > 1 ||
890  {
891  path = (Path *) create_material_path(rel, path);
892  }
893 
894  add_path(rel, path);
895 
896  /* For the moment, at least, there are no other paths to consider */
897 }
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
MaterialPath * create_material_path(RelOptInfo *rel, Path *subpath)
Definition: pathnode.c:1495
Relids lateral_relids
Definition: pathnodes.h:690
Relids all_baserels
Definition: pathnodes.h:227
BMS_Membership bms_membership(const Bitmapset *a)
Definition: bitmapset.c:672
Path * create_samplescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:954
TsmRoutine * GetTsmRoutine(Oid tsmhandler)
Definition: tablesample.c:27
bool repeatable_across_scans
Definition: tsmapi.h:65
Index query_level
Definition: pathnodes.h:183
struct TableSampleClause * tablesample
Definition: parsenodes.h:1006

◆ set_tablesample_rel_size()

static void set_tablesample_rel_size ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 816 of file allpaths.c.

References TableSampleClause::args, check_index_predicates(), GetTsmRoutine(), RelOptInfo::pages, TsmRoutine::SampleScanGetSampleSize, set_baserel_size_estimates(), RangeTblEntry::tablesample, TableSampleClause::tsmhandler, and RelOptInfo::tuples.

Referenced by set_rel_size().

817 {
818  TableSampleClause *tsc = rte->tablesample;
819  TsmRoutine *tsm;
820  BlockNumber pages;
821  double tuples;
822 
823  /*
824  * Test any partial indexes of rel for applicability. We must do this
825  * first since partial unique indexes can affect size estimates.
826  */
827  check_index_predicates(root, rel);
828 
829  /*
830  * Call the sampling method's estimation function to estimate the number
831  * of pages it will read and the number of tuples it will return. (Note:
832  * we assume the function returns sane values.)
833  */
834  tsm = GetTsmRoutine(tsc->tsmhandler);
835  tsm->SampleScanGetSampleSize(root, rel, tsc->args,
836  &pages, &tuples);
837 
838  /*
839  * For the moment, because we will only consider a SampleScan path for the
840  * rel, it's okay to just overwrite the pages and tuples estimates for the
841  * whole relation. If we ever consider multiple path types for sampled
842  * rels, we'll need more complication.
843  */
844  rel->pages = pages;
845  rel->tuples = tuples;
846 
847  /* Mark rel with estimated output rows, width, etc */
848  set_baserel_size_estimates(root, rel);
849 }
double tuples
Definition: pathnodes.h:705
uint32 BlockNumber
Definition: block.h:31
void check_index_predicates(PlannerInfo *root, RelOptInfo *rel)
Definition: indxpath.c:3395
SampleScanGetSampleSize_function SampleScanGetSampleSize
Definition: tsmapi.h:68
void set_baserel_size_estimates(PlannerInfo *root, RelOptInfo *rel)
Definition: costsize.c:4627
TsmRoutine * GetTsmRoutine(Oid tsmhandler)
Definition: tablesample.c:27
BlockNumber pages
Definition: pathnodes.h:704
struct TableSampleClause * tablesample
Definition: parsenodes.h:1006

◆ set_values_pathlist()

static void set_values_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 2456 of file allpaths.c.

References add_path(), create_valuesscan_path(), and RelOptInfo::lateral_relids.

Referenced by set_rel_pathlist().

2457 {
2458  Relids required_outer;
2459 
2460  /*
2461  * We don't support pushing join clauses into the quals of a values scan,
2462  * but it could still have required parameterization due to LATERAL refs
2463  * in the values expressions.
2464  */
2465  required_outer = rel->lateral_relids;
2466 
2467  /* Generate appropriate path */
2468  add_path(rel, create_valuesscan_path(root, rel, required_outer));
2469 }
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
Path * create_valuesscan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:1964
Relids lateral_relids
Definition: pathnodes.h:690

◆ set_worktable_pathlist()

static void set_worktable_pathlist ( PlannerInfo root,
RelOptInfo rel,
RangeTblEntry rte 
)
static

Definition at line 2626 of file allpaths.c.

References add_path(), create_worktablescan_path(), RangeTblEntry::ctelevelsup, RangeTblEntry::ctename, elog, ERROR, RelOptInfo::lateral_relids, PlannerInfo::non_recursive_path, PlannerInfo::parent_root, Path::rows, and set_cte_size_estimates().

Referenced by set_rel_size().

2627 {
2628  Path *ctepath;
2629  PlannerInfo *cteroot;
2630  Index levelsup;
2631  Relids required_outer;
2632 
2633  /*
2634  * We need to find the non-recursive term's path, which is in the plan
2635  * level that's processing the recursive UNION, which is one level *below*
2636  * where the CTE comes from.
2637  */
2638  levelsup = rte->ctelevelsup;
2639  if (levelsup == 0) /* shouldn't happen */
2640  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
2641  levelsup--;
2642  cteroot = root;
2643  while (levelsup-- > 0)
2644  {
2645  cteroot = cteroot->parent_root;
2646  if (!cteroot) /* shouldn't happen */
2647  elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
2648  }
2649  ctepath = cteroot->non_recursive_path;
2650  if (!ctepath) /* shouldn't happen */
2651  elog(ERROR, "could not find path for CTE \"%s\"", rte->ctename);
2652 
2653  /* Mark rel with estimated output rows, width, etc */
2654  set_cte_size_estimates(root, rel, ctepath->rows);
2655 
2656  /*
2657  * We don't support pushing join clauses into the quals of a worktable
2658  * scan, but it could still have required parameterization due to LATERAL
2659  * refs in its tlist. (I'm not sure this is actually possible given the
2660  * restrictions on recursive references, but it's easy enough to support.)
2661  */
2662  required_outer = rel->lateral_relids;
2663 
2664  /* Generate appropriate path */
2665  add_path(rel, create_worktablescan_path(root, rel, required_outer));
2666 }
void add_path(RelOptInfo *parent_rel, Path *new_path)
Definition: pathnode.c:422
PlannerInfo * parent_root
Definition: pathnodes.h:185
void set_cte_size_estimates(PlannerInfo *root, RelOptInfo *rel, double cte_rows)
Definition: costsize.c:5307
Relids lateral_relids
Definition: pathnodes.h:690
#define ERROR
Definition: elog.h:43
Path * create_worktablescan_path(PlannerInfo *root, RelOptInfo *rel, Relids required_outer)
Definition: pathnode.c:2067
unsigned int Index
Definition: c.h:475
double rows
Definition: pathnodes.h:1154
struct Path * non_recursive_path
Definition: pathnodes.h:354
Index ctelevelsup
Definition: parsenodes.h:1080
char * ctename
Definition: parsenodes.h:1079
#define elog(elevel,...)
Definition: elog.h:214

◆ standard_join_search()

RelOptInfo* standard_join_search ( PlannerInfo root,
int  levels_needed,
List initial_rels 
)

Definition at line 3062 of file allpaths.c.

References Assert, elog, ERROR, generate_partitionwise_join_paths(), generate_useful_gather_paths(), PlannerInfo::join_rel_level, join_search_one_level(), lfirst, linitial, list_length(), NIL, palloc0(), and set_cheapest().

Referenced by make_rel_from_joinlist().

3063 {
3064  int lev;
3065  RelOptInfo *rel;
3066 
3067  /*
3068  * This function cannot be invoked recursively within any one planning
3069  * problem, so join_rel_level[] can't be in use already.
3070  */
3071  Assert(root->join_rel_level == NULL);
3072 
3073  /*
3074  * We employ a simple "dynamic programming" algorithm: we first find all
3075  * ways to build joins of two jointree items, then all ways to build joins
3076  * of three items (from two-item joins and single items), then four-item
3077  * joins, and so on until we have considered all ways to join all the
3078  * items into one rel.
3079  *
3080  * root->join_rel_level[j] is a list of all the j-item rels. Initially we
3081  * set root->join_rel_level[1] to represent all the single-jointree-item
3082  * relations.
3083  */
3084  root->join_rel_level = (List **) palloc0((levels_needed + 1) * sizeof(List *));
3085 
3086  root->join_rel_level[1] = initial_rels;
3087 
3088  for (lev = 2; lev <= levels_needed; lev++)
3089  {
3090  ListCell *lc;
3091 
3092  /*
3093  * Determine all possible pairs of relations to be joined at this
3094  * level, and build paths for making each one from every available
3095  * pair of lower-level relations.
3096  */
3097  join_search_one_level(root, lev);
3098 
3099  /*
3100  * Run generate_partitionwise_join_paths() and generate_gather_paths()
3101  * for each just-processed joinrel. We could not do this earlier
3102  * because both regular and partial paths can get added to a
3103  * particular joinrel at multiple times within join_search_one_level.
3104  *
3105  * After that, we're done creating paths for the joinrel, so run
3106  * set_cheapest().
3107  */
3108  foreach(lc, root->join_rel_level[lev])
3109  {
3110  rel = (RelOptInfo *) lfirst(lc);
3111 
3112  /* Create paths for partitionwise joins. */
3114 
3115  /*
3116  * Except for the topmost scan/join rel, consider gathering
3117  * partial paths. We'll do the same for the topmost scan/join rel
3118  * once we know the final targetlist (see grouping_planner).
3119  */
3120  if (lev < levels_needed)
3121  generate_useful_gather_paths(root, rel, false);
3122 
3123  /* Find and save the cheapest paths for this rel */
3124  set_cheapest(rel);
3125 
3126 #ifdef OPTIMIZER_DEBUG
3127  debug_print_rel(root, rel);
3128 #endif
3129  }
3130  }
3131 
3132  /*
3133  * We should have a single rel at the final level.
3134  */
3135  if (root->join_rel_level[levels_needed] == NIL)
3136  elog(ERROR, "failed to build any %d-way joins", levels_needed);
3137  Assert(list_length(root->join_rel_level[levels_needed]) == 1);
3138 
3139  rel = (RelOptInfo *) linitial(root->join_rel_level[levels_needed]);
3140 
3141  root->join_rel_level = NULL;
3142 
3143  return rel;
3144 }
#define NIL
Definition: pg_list.h:65
void generate_partitionwise_join_paths(PlannerInfo *root, RelOptInfo *rel)
Definition: allpaths.c:3882
#define linitial(l)
Definition: pg_list.h:195
void generate_useful_gather_paths(PlannerInfo *root, RelOptInfo *rel, bool override_rows)
Definition: allpaths.c:2816
#define ERROR
Definition: elog.h:43
void join_search_one_level(PlannerInfo *root, int level)
Definition: joinrels.c:71
void set_cheapest(RelOptInfo *parent_rel)
Definition: pathnode.c:244
void * palloc0(Size size)
Definition: mcxt.c:980
#define Assert(condition)
Definition: c.h:738
#define lfirst(lc)
Definition: pg_list.h:190
List ** join_rel_level
Definition: pathnodes.h:256
static int list_length(const List *l)
Definition: pg_list.h:169
#define elog(elevel,...)
Definition: elog.h:214
Definition: pg_list.h:50

◆ subquery_is_pushdown_safe()

static bool subquery_is_pushdown_safe ( Query subquery,
Query topquery,
pushdown_safety_info safetyInfo 
)
static

Definition at line 3220 of file allpaths.c.

References Assert, castNode, check_output_expressions(), SetOperationStmt::colTypes, compare_tlist_datatypes(), Query::distinctClause, Query::hasTargetSRFs, Query::hasWindowFuncs, Query::limitCount, Query::limitOffset, recurse_pushdown_safe(), Query::setOperations, Query::targetList, and pushdown_safety_info::unsafeVolatile.

Referenced by recurse_pushdown_safe(), and set_subquery_pathlist().

3222 {
3223  SetOperationStmt *topop;
3224 
3225  /* Check point 1 */
3226  if (subquery->limitOffset != NULL || subquery->limitCount != NULL)
3227  return false;
3228 
3229  /* Check points 3, 4, and 5 */
3230  if (subquery->distinctClause ||
3231  subquery->hasWindowFuncs ||
3232  subquery->hasTargetSRFs)
3233  safetyInfo->unsafeVolatile = true;
3234 
3235  /*
3236  * If we're at a leaf query, check for unsafe expressions in its target
3237  * list, and mark any unsafe ones in unsafeColumns[]. (Non-leaf nodes in
3238  * setop trees have only simple Vars in their tlists, so no need to check
3239  * them.)
3240  */
3241  if (subquery->setOperations == NULL)
3242  check_output_expressions(subquery, safetyInfo);
3243 
3244  /* Are we at top level, or looking at a setop component? */
3245  if (subquery == topquery)
3246  {
3247  /* Top level, so check any component queries */
3248  if (subquery->setOperations != NULL)
3249  if (!recurse_pushdown_safe(subquery->setOperations, topquery,
3250  safetyInfo))
3251  return false;
3252  }
3253  else
3254  {
3255  /* Setop component must not have more components (too weird) */
3256  if (subquery->setOperations != NULL)
3257  return false;
3258  /* Check whether setop component output types match top level */
3259  topop = castNode(SetOperationStmt, topquery->setOperations);
3260  Assert(topop);
3262  topop->colTypes,
3263  safetyInfo);
3264  }
3265  return true;
3266 }
Node * limitOffset
Definition: parsenodes.h:160
#define castNode(_type_, nodeptr)
Definition: nodes.h:598
static bool recurse_pushdown_safe(Node *setOp, Query *topquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3272
static void compare_tlist_datatypes(List *tlist, List *colTypes, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3407
List * targetList
Definition: parsenodes.h:140
List * distinctClause
Definition: parsenodes.h:156
Node * limitCount
Definition: parsenodes.h:161
static void check_output_expressions(Query *subquery, pushdown_safety_info *safetyInfo)
Definition: allpaths.c:3339
bool hasTargetSRFs
Definition: parsenodes.h:127
#define Assert(condition)
Definition: c.h:738
bool hasWindowFuncs
Definition: parsenodes.h:126
Node * setOperations
Definition: parsenodes.h:166

◆ subquery_push_qual()

static void subquery_push_qual ( Query subquery,
RangeTblEntry rte,
Index  rti,
Node qual 
)
static

Definition at line 3559 of file allpaths.c.

References Query::groupClause, Query::groupingSets, Query::hasAggs, Query::hasSubLinks, Query::havingQual, Query::jointree, make_and_qual(), FromExpr::quals, recurse_push_qual(), REPLACEVARS_REPORT_ERROR, ReplaceVarsFromTargetList(), Query::setOperations, and Query::targetList.

Referenced by recurse_push_qual(), and set_subquery_pathlist().

3560 {
3561  if (subquery->setOperations != NULL)
3562  {
3563  /* Recurse to push it separately to each component query */
3564  recurse_push_qual(subquery->setOperations, subquery,
3565  rte, rti, qual);
3566  }
3567  else
3568  {
3569  /*
3570  * We need to replace Vars in the qual (which must refer to outputs of
3571  * the subquery) with copies of the subquery's targetlist expressions.
3572  * Note that at this point, any uplevel Vars in the qual should have
3573  * been replaced with Params, so they need no work.
3574  *
3575  * This step also ensures that when we are pushing into a setop tree,
3576  * each component query gets its own copy of the qual.
3577  */
3578  qual = ReplaceVarsFromTargetList(qual, rti, 0, rte,
3579  subquery->targetList,
3581  &subquery->hasSubLinks);
3582 
3583  /*
3584  * Now attach the qual to the proper place: normally WHERE, but if the
3585  * subquery uses grouping or aggregation, put it in HAVING (since the
3586  * qual really refers to the group-result rows).
3587  */
3588  if (subquery->hasAggs || subquery->groupClause || subquery->groupingSets || subquery->havingQual)
3589  subquery->havingQual = make_and_qual(subquery->havingQual, qual);
3590  else
3591  subquery->jointree->quals =
3592  make_and_qual(subquery->jointree->quals, qual);
3593 
3594  /*
3595  * We need not change the subquery's hasAggs or hasSubLinks flags,
3596  * since we can't be pushing down any aggregates that weren't there
3597  * before, and we don't push down subselects at all.
3598  */
3599  }
3600 }
FromExpr * jointree
Definition: parsenodes.h:138
bool hasAggs
Definition: parsenodes.h:125
List * groupingSets
Definition: parsenodes.h:150
Node * make_and_qual(Node *qual1, Node *qual2)
Definition: makefuncs.c:688
Node * quals
Definition: primnodes.h:1511
List * targetList
Definition: parsenodes.h:140
Node * ReplaceVarsFromTargetList(Node *node, int target_varno, int sublevels_up, RangeTblEntry *target_rte, List *targetlist, ReplaceVarsNoMatchOption nomatch_option, int nomatch_varno, bool *outer_hasSubLinks)
static void recurse_push_qual(Node *setOp, Query *topquery, RangeTblEntry *rte, Index rti, Node *qual)
Definition: allpaths.c:3606
Node * setOperations
Definition: parsenodes.h:166
List * groupClause
Definition: parsenodes.h:148
bool hasSubLinks
Definition: parsenodes.h:128
Node * havingQual
Definition: parsenodes.h:152

◆ targetIsInAllPartitionLists()

static bool targetIsInAllPartitionLists ( TargetEntry tle,
Query query 
)
static

Definition at line 3440 of file allpaths.c.

References InvalidOid, lfirst, WindowClause::partitionClause, targetIsInSortList(), and Query::windowClause.

Referenced by check_output_expressions().

3441 {
3442  ListCell *lc;
3443 
3444  foreach(lc, query->windowClause)
3445  {
3446  WindowClause *wc = (WindowClause *) lfirst(lc);
3447 
3449  return false;
3450  }
3451  return true;
3452 }
List * windowClause
Definition: parsenodes.h:154
List * partitionClause
Definition: parsenodes.h:1353
#define InvalidOid
Definition: postgres_ext.h:36
bool targetIsInSortList(TargetEntry *tle, Oid sortop, List *sortList)
#define lfirst(lc)
Definition: pg_list.h:190

Variable Documentation

◆ enable_geqo

bool enable_geqo = false

Definition at line 62 of file allpaths.c.

Referenced by make_rel_from_joinlist().

◆ geqo_threshold

int geqo_threshold

Definition at line 63 of file allpaths.c.

Referenced by make_rel_from_joinlist().

◆ join_search_hook

join_search_hook_type join_search_hook = NULL

Definition at line 71 of file allpaths.c.

Referenced by make_rel_from_joinlist().

◆ min_parallel_index_scan_size

int min_parallel_index_scan_size

Definition at line 65 of file allpaths.c.

Referenced by compute_parallel_vacuum_workers(), and compute_parallel_worker().

◆ min_parallel_table_scan_size

int min_parallel_table_scan_size

Definition at line 64 of file allpaths.c.

Referenced by compute_parallel_worker().

◆ set_rel_pathlist_hook

set_rel_pathlist_hook_type set_rel_pathlist_hook = NULL

Definition at line 68 of file allpaths.c.

Referenced by set_rel_pathlist().