* allpaths.c
* Routines to find possible search paths for processing a query
*
- * Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/optimizer/path/allpaths.c,v 1.78 2001/07/31 17:56:30 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.175 2008/10/21 20:42:52 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
+#include <math.h>
+
+#include "nodes/nodeFuncs.h"
+#ifdef OPTIMIZER_DEBUG
+#include "nodes/print.h"
+#endif
#include "optimizer/clauses.h"
#include "optimizer/cost.h"
#include "optimizer/geqo.h"
#include "optimizer/plancat.h"
#include "optimizer/planner.h"
#include "optimizer/prep.h"
+#include "optimizer/var.h"
+#include "parser/parse_clause.h"
#include "parser/parsetree.h"
#include "rewrite/rewriteManip.h"
-bool enable_geqo = true;
-int geqo_rels = DEFAULT_GEQO_RELS;
+/* These parameters are set by GUC */
+bool enable_geqo = false; /* just in case GUC doesn't set it */
+int geqo_threshold;
+/* Hook for plugins to replace standard_join_search() */
+join_search_hook_type join_search_hook = NULL;
-static void set_base_rel_pathlists(Query *root);
-static void set_plain_rel_pathlist(Query *root, RelOptInfo *rel,
- RangeTblEntry *rte);
-static void set_inherited_rel_pathlist(Query *root, RelOptInfo *rel,
- Index rti, RangeTblEntry *rte,
- List *inheritlist);
-static void set_subquery_pathlist(Query *root, RelOptInfo *rel,
- Index rti, RangeTblEntry *rte);
-static RelOptInfo *make_one_rel_by_joins(Query *root, int levels_needed,
- List *initial_rels);
-#ifdef OPTIMIZER_DEBUG
-static void debug_print_rel(Query *root, RelOptInfo *rel);
-
-#endif
+static void set_base_rel_pathlists(PlannerInfo *root);
+static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ Index rti, RangeTblEntry *rte);
+static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ RangeTblEntry *rte);
+static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ Index rti, RangeTblEntry *rte);
+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_cte_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ RangeTblEntry *rte);
+static void set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ RangeTblEntry *rte);
+static RelOptInfo *make_rel_from_joinlist(PlannerInfo *root, List *joinlist);
+static bool subquery_is_pushdown_safe(Query *subquery, Query *topquery,
+ bool *differentTypes);
+static bool recurse_pushdown_safe(Node *setOp, Query *topquery,
+ bool *differentTypes);
+static void compare_tlist_datatypes(List *tlist, List *colTypes,
+ bool *differentTypes);
+static bool qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual,
+ bool *differentTypes);
+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);
/*
* single rel that represents the join of all base rels in the query.
*/
RelOptInfo *
-make_one_rel(Query *root)
+make_one_rel(PlannerInfo *root, List *joinlist)
{
RelOptInfo *rel;
/*
* Generate access paths for the entire join tree.
*/
- Assert(root->jointree != NULL && IsA(root->jointree, FromExpr));
-
- rel = make_fromexpr_rel(root, root->jointree);
+ rel = make_rel_from_joinlist(root, joinlist);
/*
- * The result should join all the query's base rels.
+ * The result should join all and only the query's base rels.
*/
- Assert(length(rel->relids) == length(root->base_rel_list));
+#ifdef USE_ASSERT_CHECKING
+ {
+ int num_base_rels = 0;
+ Index rti;
+
+ for (rti = 1; rti < root->simple_rel_array_size; rti++)
+ {
+ RelOptInfo *brel = root->simple_rel_array[rti];
+
+ if (brel == NULL)
+ continue;
+
+ Assert(brel->relid == rti); /* sanity check on array */
+
+ /* ignore RTEs that are "other rels" */
+ if (brel->reloptkind != RELOPT_BASEREL)
+ continue;
+
+ Assert(bms_is_member(rti, rel->relids));
+ num_base_rels++;
+ }
+
+ Assert(bms_num_members(rel->relids) == num_base_rels);
+ }
+#endif
return rel;
}
* Each useful path is attached to its relation's 'pathlist' field.
*/
static void
-set_base_rel_pathlists(Query *root)
+set_base_rel_pathlists(PlannerInfo *root)
{
- List *rellist;
+ Index rti;
- foreach(rellist, root->base_rel_list)
+ for (rti = 1; rti < root->simple_rel_array_size; rti++)
{
- RelOptInfo *rel = (RelOptInfo *) lfirst(rellist);
- Index rti;
- RangeTblEntry *rte;
- List *inheritlist;
+ RelOptInfo *rel = root->simple_rel_array[rti];
- Assert(length(rel->relids) == 1); /* better be base rel */
- rti = lfirsti(rel->relids);
- rte = rt_fetch(rti, root->rtable);
+ /* there may be empty slots corresponding to non-baserel RTEs */
+ if (rel == NULL)
+ continue;
- if (rel->issubquery)
- {
- /* Subquery --- generate a separate plan for it */
- set_subquery_pathlist(root, rel, rti, rte);
- }
- else if ((inheritlist = expand_inherted_rtentry(root, rti, true))
- != NIL)
- {
- /* Relation is root of an inheritance tree, process specially */
- set_inherited_rel_pathlist(root, rel, rti, rte, inheritlist);
- }
+ Assert(rel->relid == rti); /* sanity check on array */
+
+ /* ignore RTEs that are "other rels" */
+ if (rel->reloptkind != RELOPT_BASEREL)
+ continue;
+
+ set_rel_pathlist(root, rel, rti, root->simple_rte_array[rti]);
+ }
+}
+
+/*
+ * set_rel_pathlist
+ * Build access paths for a base relation
+ */
+static void
+set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ Index rti, RangeTblEntry *rte)
+{
+ if (rte->inh)
+ {
+ /* It's an "append relation", process accordingly */
+ set_append_rel_pathlist(root, rel, rti, rte);
+ }
+ else if (rel->rtekind == RTE_SUBQUERY)
+ {
+ /* Subquery --- generate a separate plan for it */
+ set_subquery_pathlist(root, rel, rti, rte);
+ }
+ else if (rel->rtekind == RTE_FUNCTION)
+ {
+ /* RangeFunction --- generate a suitable path for it */
+ set_function_pathlist(root, rel, rte);
+ }
+ else if (rel->rtekind == RTE_VALUES)
+ {
+ /* Values list --- generate a suitable path for it */
+ set_values_pathlist(root, rel, rte);
+ }
+ else if (rel->rtekind == RTE_CTE)
+ {
+ /* CTE reference --- generate a suitable path for it */
+ if (rte->self_reference)
+ set_worktable_pathlist(root, rel, rte);
else
- {
- /* Plain relation */
- set_plain_rel_pathlist(root, rel, rte);
- }
+ set_cte_pathlist(root, rel, rte);
}
+ else
+ {
+ /* Plain relation */
+ Assert(rel->rtekind == RTE_RELATION);
+ set_plain_rel_pathlist(root, rel, rte);
+ }
+
+#ifdef OPTIMIZER_DEBUG
+ debug_print_rel(root, rel);
+#endif
}
/*
* Build access paths for a plain relation (no subquery, no inheritance)
*/
static void
-set_plain_rel_pathlist(Query *root, RelOptInfo *rel, RangeTblEntry *rte)
+set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
{
+ /*
+ * If we can prove we don't need to scan the rel via constraint exclusion,
+ * set up a single dummy path for it. We only need to check for regular
+ * baserels; if it's an otherrel, CE was already checked in
+ * set_append_rel_pathlist().
+ */
+ if (rel->reloptkind == RELOPT_BASEREL &&
+ relation_excluded_by_constraints(root, rel, rte))
+ {
+ set_dummy_rel_pathlist(rel);
+ return;
+ }
+
/* Mark rel with estimated output rows, width, etc */
set_baserel_size_estimates(root, rel);
+ /* Test any partial indexes of rel for applicability */
+ check_partial_indexes(root, rel);
+
+ /*
+ * Check to see if we can extract any restriction conditions from join
+ * quals that are OR-of-AND structures. If so, add them to the rel's
+ * restriction list, and recompute the size estimates.
+ */
+ if (create_or_index_quals(root, rel))
+ set_baserel_size_estimates(root, rel);
+
/*
* Generate paths and add them to the rel's pathlist.
*
/* Consider sequential scan */
add_path(rel, create_seqscan_path(root, rel));
- /* Consider TID scans */
- create_tidscan_paths(root, rel);
-
- /* Consider index paths for both simple and OR index clauses */
+ /* Consider index scans */
create_index_paths(root, rel);
- /* create_index_paths must be done before create_or_index_paths */
- create_or_index_paths(root, rel);
+ /* Consider TID scans */
+ create_tidscan_paths(root, rel);
/* Now find the cheapest of the paths for this rel */
set_cheapest(rel);
}
/*
- * set_inherited_rel_pathlist
- * Build access paths for a inheritance tree rooted at rel
- *
- * inheritlist is a list of RT indexes of all tables in the inheritance tree,
- * including a duplicate of the parent itself. Note we will not come here
- * unless there's at least one child in addition to the parent.
+ * set_append_rel_pathlist
+ * Build access paths for an "append relation"
*
- * NOTE: the passed-in rel and RTE will henceforth represent the appended
- * result of the whole inheritance tree. The members of inheritlist represent
- * the individual tables --- in particular, the inheritlist member that is a
- * duplicate of the parent RTE represents the parent table alone.
- * We will generate plans to scan the individual tables that refer to
- * the inheritlist RTEs, whereas Vars elsewhere in the plan tree that
- * refer to the original RTE are taken to refer to the append output.
- * In particular, this means we have separate RelOptInfos for the parent
- * table and for the append output, which is a good thing because they're
- * not the same size.
+ * The passed-in rel and RTE represent the entire append relation. The
+ * relation's contents are computed by appending together the output of
+ * the individual member relations. Note that in the inheritance case,
+ * the first member relation is actually the same table as is mentioned in
+ * the parent RTE ... but it has a different RTE and RelOptInfo. This is
+ * a good thing because their outputs are not the same size.
*/
static void
-set_inherited_rel_pathlist(Query *root, RelOptInfo *rel,
- Index rti, RangeTblEntry *rte,
- List *inheritlist)
+set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
+ Index rti, RangeTblEntry *rte)
{
int parentRTindex = rti;
- Oid parentOID = rte->relid;
List *subpaths = NIL;
- List *il;
+ double parent_rows;
+ double parent_size;
+ double *parent_attrsizes;
+ int nattrs;
+ ListCell *l;
/*
- * XXX for now, can't handle inherited expansion of FOR UPDATE; can we
- * do better?
+ * XXX for now, can't handle inherited expansion of FOR UPDATE/SHARE; can
+ * we do better? (This will take some redesign because the executor
+ * currently supposes that every rowMark relation is involved in every row
+ * returned by the query.)
*/
- if (intMember(parentRTindex, root->rowMarks))
- elog(ERROR, "SELECT FOR UPDATE is not supported for inherit queries");
+ if (get_rowmark(root->parse, parentRTindex))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("SELECT FOR UPDATE/SHARE is not supported for inheritance queries")));
/*
- * The executor will check the parent table's access permissions when it
- * examines the parent's inheritlist entry. There's no need to check
- * twice, so turn off access check bits in the original RTE.
- */
- rte->checkForRead = false;
- rte->checkForWrite = false;
-
- /*
- * Initialize to compute size estimates for whole inheritance tree
+ * Initialize to compute size estimates for whole append relation.
+ *
+ * We handle width estimates by weighting the widths of different
+ * child rels proportionally to their number of rows. This is sensible
+ * because the use of width estimates is mainly to compute the total
+ * relation "footprint" if we have to sort or hash it. To do this,
+ * we sum the total equivalent size (in "double" arithmetic) and then
+ * divide by the total rowcount estimate. This is done separately for
+ * the total rel width and each attribute.
+ *
+ * Note: if you consider changing this logic, beware that child rels could
+ * have zero rows and/or width, if they were excluded by constraints.
*/
- rel->rows = 0;
- rel->width = 0;
+ parent_rows = 0;
+ parent_size = 0;
+ nattrs = rel->max_attr - rel->min_attr + 1;
+ parent_attrsizes = (double *) palloc0(nattrs * sizeof(double));
/*
- * Generate access paths for each table in the tree (parent AND
- * children), and pick the cheapest path for each table.
+ * Generate access paths for each member relation, and pick the cheapest
+ * path for each one.
*/
- foreach(il, inheritlist)
+ foreach(l, root->append_rel_list)
{
- int childRTindex = lfirsti(il);
- RangeTblEntry *childrte;
- Oid childOID;
+ AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
+ int childRTindex;
+ RangeTblEntry *childRTE;
RelOptInfo *childrel;
+ Path *childpath;
+ ListCell *parentvars;
+ ListCell *childvars;
- childrte = rt_fetch(childRTindex, root->rtable);
- childOID = childrte->relid;
+ /* append_rel_list contains all append rels; ignore others */
+ if (appinfo->parent_relid != parentRTindex)
+ continue;
+
+ childRTindex = appinfo->child_relid;
+ childRTE = root->simple_rte_array[childRTindex];
/*
- * Make a RelOptInfo for the child so we can do planning. Do NOT
- * attach the RelOptInfo to the query's base_rel_list, however,
- * since the child is not part of the main join tree. Instead,
- * the child RelOptInfo is added to other_rel_list.
+ * The child rel's RelOptInfo was already created during
+ * add_base_rels_to_query.
*/
- childrel = build_other_rel(root, childRTindex);
+ childrel = find_base_rel(root, childRTindex);
+ Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
/*
- * Copy the parent's targetlist and restriction quals to the
- * child, with attribute-number adjustment as needed. We don't
- * bother to copy the join quals, since we can't do any joining
- * of the individual tables.
+ * We have to copy the parent's targetlist and quals to the child,
+ * with appropriate substitution of variables. However, only the
+ * baserestrictinfo quals are needed before we can check for
+ * constraint exclusion; so do that first and then check to see if we
+ * can disregard this child.
*/
- childrel->targetlist = (List *)
- adjust_inherited_attrs((Node *) rel->targetlist,
- parentRTindex,
- parentOID,
- childRTindex,
- childOID);
childrel->baserestrictinfo = (List *)
- adjust_inherited_attrs((Node *) rel->baserestrictinfo,
- parentRTindex,
- parentOID,
- childRTindex,
- childOID);
- childrel->baserestrictcost = rel->baserestrictcost;
+ adjust_appendrel_attrs((Node *) rel->baserestrictinfo,
+ appinfo);
+
+ if (relation_excluded_by_constraints(root, childrel, childRTE))
+ {
+ /*
+ * This child need not be scanned, so we can omit it from the
+ * appendrel. Mark it with a dummy cheapest-path though, in case
+ * best_appendrel_indexscan() looks at it later.
+ */
+ set_dummy_rel_pathlist(childrel);
+ continue;
+ }
+
+ /* CE failed, so finish copying targetlist and join quals */
+ childrel->joininfo = (List *)
+ adjust_appendrel_attrs((Node *) rel->joininfo,
+ appinfo);
+ childrel->reltargetlist = (List *)
+ adjust_appendrel_attrs((Node *) rel->reltargetlist,
+ appinfo);
+
+ /*
+ * We have to make child entries in the EquivalenceClass data
+ * structures as well.
+ */
+ if (rel->has_eclass_joins)
+ {
+ add_child_rel_equivalences(root, appinfo, rel, childrel);
+ childrel->has_eclass_joins = true;
+ }
+
+ /*
+ * Copy the parent's attr_needed data as well, with appropriate
+ * adjustment of relids and attribute numbers.
+ */
+ pfree(childrel->attr_needed);
+ childrel->attr_needed =
+ adjust_appendrel_attr_needed(rel, appinfo,
+ childrel->min_attr,
+ childrel->max_attr);
+
+ /*
+ * Compute the child's access paths, and add the cheapest one to the
+ * Append path we are constructing for the parent.
+ *
+ * It's possible that the child is itself an appendrel, in which case
+ * we can "cut out the middleman" and just add its child paths to our
+ * own list. (We don't try to do this earlier because we need to
+ * apply both levels of transformation to the quals.)
+ */
+ set_rel_pathlist(root, childrel, childRTindex, childRTE);
+
+ childpath = childrel->cheapest_total_path;
+ if (IsA(childpath, AppendPath))
+ subpaths = list_concat(subpaths,
+ ((AppendPath *) childpath)->subpaths);
+ else
+ subpaths = lappend(subpaths, childpath);
/*
- * Now compute child access paths, and save the cheapest.
+ * Accumulate size information from each child.
*/
- set_plain_rel_pathlist(root, childrel, childrte);
+ if (childrel->rows > 0)
+ {
+ parent_rows += childrel->rows;
+ parent_size += childrel->width * childrel->rows;
+
+ forboth(parentvars, rel->reltargetlist,
+ childvars, childrel->reltargetlist)
+ {
+ Var *parentvar = (Var *) lfirst(parentvars);
+ Var *childvar = (Var *) lfirst(childvars);
+
+ /*
+ * Accumulate per-column estimates too. Whole-row Vars and
+ * PlaceHolderVars can be ignored here.
+ */
+ if (IsA(parentvar, Var) &&
+ IsA(childvar, Var))
+ {
+ int pndx = parentvar->varattno - rel->min_attr;
+ int cndx = childvar->varattno - childrel->min_attr;
+
+ parent_attrsizes[pndx] += childrel->attr_widths[cndx] * childrel->rows;
+ }
+ }
+ }
+ }
- subpaths = lappend(subpaths, childrel->cheapest_total_path);
+ /*
+ * Save the finished size estimates.
+ */
+ rel->rows = parent_rows;
+ if (parent_rows > 0)
+ {
+ int i;
- /* Also update total size estimates */
- rel->rows += childrel->rows;
- if (childrel->width > rel->width)
- rel->width = childrel->width;
+ rel->width = rint(parent_size / parent_rows);
+ for (i = 0; i < nattrs; i++)
+ rel->attr_widths[i] = rint(parent_attrsizes[i] / parent_rows);
}
+ else
+ rel->width = 0; /* attr_widths should be zero already */
+
+ /*
+ * Set "raw tuples" count equal to "rows" for the appendrel; needed
+ * because some places assume rel->tuples is valid for any baserel.
+ */
+ rel->tuples = parent_rows;
+
+ pfree(parent_attrsizes);
/*
- * Finally, build Append path and install it as the only access path
- * for the parent rel.
+ * Finally, build Append path and install it as the only access path for
+ * the parent rel. (Note: this is correct even if we have zero or one
+ * live subpath due to constraint exclusion.)
*/
add_path(rel, (Path *) create_append_path(rel, subpaths));
set_cheapest(rel);
}
+/*
+ * set_dummy_rel_pathlist
+ * Build a dummy path for a relation that's been excluded by constraints
+ *
+ * Rather than inventing a special "dummy" path type, we represent this as an
+ * AppendPath with no members (see also IS_DUMMY_PATH macro).
+ */
+static void
+set_dummy_rel_pathlist(RelOptInfo *rel)
+{
+ /* Set dummy size estimates --- we leave attr_widths[] as zeroes */
+ rel->rows = 0;
+ rel->width = 0;
+
+ add_path(rel, (Path *) create_append_path(rel, NIL));
+
+ /* Select cheapest path (pretty easy in this case...) */
+ set_cheapest(rel);
+}
+
+/* quick-and-dirty test to see if any joining is needed */
+static bool
+has_multiple_baserels(PlannerInfo *root)
+{
+ int num_base_rels = 0;
+ Index rti;
+
+ for (rti = 1; rti < root->simple_rel_array_size; rti++)
+ {
+ RelOptInfo *brel = root->simple_rel_array[rti];
+
+ if (brel == NULL)
+ continue;
+
+ /* ignore RTEs that are "other rels" */
+ if (brel->reloptkind == RELOPT_BASEREL)
+ if (++num_base_rels > 1)
+ return true;
+ }
+ return false;
+}
+
/*
* set_subquery_pathlist
* Build the (single) access path for a subquery RTE
*/
static void
-set_subquery_pathlist(Query *root, RelOptInfo *rel,
+set_subquery_pathlist(PlannerInfo *root, RelOptInfo *rel,
Index rti, RangeTblEntry *rte)
{
+ Query *parse = root->parse;
Query *subquery = rte->subquery;
+ bool *differentTypes;
+ double tuple_fraction;
+ PlannerInfo *subroot;
+ List *pathkeys;
+
+ /* We need a workspace for keeping track of set-op type coercions */
+ differentTypes = (bool *)
+ palloc0((list_length(subquery->targetList) + 1) * sizeof(bool));
/*
* If there are any restriction clauses that have been attached to the
- * subquery relation, consider pushing them down to become HAVING quals
- * of the subquery itself. (Not WHERE clauses, since they may refer to
- * subquery outputs that are aggregate results. But planner.c will
- * transfer them into the subquery's WHERE if they do not.) This
- * transformation is useful because it may allow us to generate a better
- * plan for the subquery than evaluating all the subquery output rows
- * and then filtering them.
- *
- * There are several cases where we cannot push down clauses:
+ * subquery relation, consider pushing them down to become WHERE or HAVING
+ * quals of the subquery itself. This transformation is useful because it
+ * may allow us to generate a better plan for the subquery than evaluating
+ * all the subquery output rows and then filtering them.
*
- * 1. If the subquery contains set ops (UNION/INTERSECT/EXCEPT) we do not
- * push down any qual clauses, since the planner doesn't support quals at
- * the top level of a setop. (With suitable analysis we could try to push
- * the quals down into the component queries of the setop, but getting it
- * right seems nontrivial. Work on this later.)
- *
- * 2. If the subquery has a LIMIT clause or a DISTINCT ON clause, we must
- * not push down any quals, since that could change the set of rows
- * returned. (Actually, we could push down quals into a DISTINCT ON
- * subquery if they refer only to DISTINCT-ed output columns, but checking
- * that seems more work than it's worth. In any case, a plain DISTINCT is
- * safe to push down past.)
- *
- * 3. We do not push down clauses that contain subselects, mainly because
- * I'm not sure it will work correctly (the subplan hasn't yet transformed
- * sublinks to subselects).
+ * There are several cases where we cannot push down clauses. Restrictions
+ * involving the subquery are checked by subquery_is_pushdown_safe().
+ * Restrictions on individual clauses are checked by
+ * qual_is_pushdown_safe(). Also, we don't want to push down
+ * pseudoconstant clauses; better to have the gating node above the
+ * subquery.
*
* Non-pushed-down clauses will get evaluated as qpquals of the
* SubqueryScan node.
*
* XXX Are there any cases where we want to make a policy decision not to
- * push down, because it'd result in a worse plan?
+ * push down a pushable qual, because it'd result in a worse plan?
*/
- if (subquery->setOperations == NULL &&
- subquery->limitOffset == NULL &&
- subquery->limitCount == NULL &&
- !has_distinct_on_clause(subquery))
+ if (rel->baserestrictinfo != NIL &&
+ subquery_is_pushdown_safe(subquery, subquery, differentTypes))
{
/* OK to consider pushing down individual quals */
List *upperrestrictlist = NIL;
- List *lst;
+ ListCell *l;
- foreach(lst, rel->baserestrictinfo)
+ foreach(l, rel->baserestrictinfo)
{
- RestrictInfo *rinfo = (RestrictInfo *) lfirst(lst);
+ RestrictInfo *rinfo = (RestrictInfo *) lfirst(l);
Node *clause = (Node *) rinfo->clause;
- if (contain_subplans(clause))
+ if (!rinfo->pseudoconstant &&
+ qual_is_pushdown_safe(subquery, rti, clause, differentTypes))
{
- /* Keep it in the upper query */
- upperrestrictlist = lappend(upperrestrictlist, rinfo);
+ /* Push it down */
+ subquery_push_qual(subquery, rte, rti, clause);
}
else
{
- /*
- * We need to replace Vars in the clause (which must refer to
- * outputs of the subquery) with copies of the subquery's
- * targetlist expressions. Note that at this point, any
- * uplevel Vars in the clause should have been replaced with
- * Params, so they need no work.
- */
- clause = ResolveNew(clause, rti, 0,
- subquery->targetList,
- CMD_SELECT, 0);
- subquery->havingQual = make_and_qual(subquery->havingQual,
- clause);
- /*
- * We need not change the subquery's hasAggs or
- * hasSublinks flags, since we can't be pushing
- * down any aggregates that weren't there before,
- * and we don't push down subselects at all.
- */
+ /* Keep it in the upper query */
+ upperrestrictlist = lappend(upperrestrictlist, rinfo);
}
}
rel->baserestrictinfo = upperrestrictlist;
}
+ pfree(differentTypes);
+
+ /*
+ * We can safely pass the outer tuple_fraction down to the subquery if the
+ * outer level has no joining, aggregation, or sorting to do. Otherwise
+ * we'd better tell the subquery to plan for full retrieval. (XXX This
+ * could probably be made more intelligent ...)
+ */
+ if (parse->hasAggs ||
+ parse->groupClause ||
+ parse->havingQual ||
+ parse->distinctClause ||
+ parse->sortClause ||
+ has_multiple_baserels(root))
+ tuple_fraction = 0.0; /* default case */
+ else
+ tuple_fraction = root->tuple_fraction;
+
/* Generate the plan for the subquery */
- rel->subplan = subquery_planner(subquery,
- -1.0 /* default case */ );
+ rel->subplan = subquery_planner(root->glob, subquery,
+ root,
+ false, tuple_fraction,
+ &subroot);
+ rel->subrtable = subroot->parse->rtable;
/* Copy number of output rows from subplan */
rel->tuples = rel->subplan->plan_rows;
/* Mark rel with estimated output rows, width, etc */
set_baserel_size_estimates(root, rel);
+ /* Convert subquery pathkeys to outer representation */
+ pathkeys = convert_subquery_pathkeys(root, rel, subroot->query_pathkeys);
+
/* Generate appropriate path */
- add_path(rel, create_subqueryscan_path(rel));
+ add_path(rel, create_subqueryscan_path(rel, pathkeys));
/* Select cheapest path (pretty easy in this case...) */
set_cheapest(rel);
}
/*
- * make_fromexpr_rel
- * Build access paths for a FromExpr jointree node.
+ * set_function_pathlist
+ * Build the (single) access path for a function RTE
*/
-RelOptInfo *
-make_fromexpr_rel(Query *root, FromExpr *from)
+static void
+set_function_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
+{
+ /* Mark rel with estimated output rows, width, etc */
+ set_function_size_estimates(root, rel);
+
+ /* Generate appropriate path */
+ add_path(rel, create_functionscan_path(root, rel));
+
+ /* Select cheapest path (pretty easy in this case...) */
+ set_cheapest(rel);
+}
+
+/*
+ * set_values_pathlist
+ * Build the (single) access path for a VALUES RTE
+ */
+static void
+set_values_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
+{
+ /* Mark rel with estimated output rows, width, etc */
+ set_values_size_estimates(root, rel);
+
+ /* Generate appropriate path */
+ add_path(rel, create_valuesscan_path(root, rel));
+
+ /* Select cheapest path (pretty easy in this case...) */
+ set_cheapest(rel);
+}
+
+/*
+ * set_cte_pathlist
+ * Build the (single) access path for a non-self-reference CTE RTE
+ */
+static void
+set_cte_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
+{
+ Plan *cteplan;
+ PlannerInfo *cteroot;
+ Index levelsup;
+ int ndx;
+ ListCell *lc;
+ int plan_id;
+
+ /*
+ * Find the referenced CTE, and locate the plan previously made for it.
+ */
+ levelsup = rte->ctelevelsup;
+ cteroot = root;
+ while (levelsup-- > 0)
+ {
+ cteroot = cteroot->parent_root;
+ if (!cteroot) /* shouldn't happen */
+ elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
+ }
+ /*
+ * Note: cte_plan_ids can be shorter than cteList, if we are still working
+ * on planning the CTEs (ie, this is a side-reference from another CTE).
+ * So we mustn't use forboth here.
+ */
+ ndx = 0;
+ foreach(lc, cteroot->parse->cteList)
+ {
+ CommonTableExpr *cte = (CommonTableExpr *) lfirst(lc);
+
+ if (strcmp(cte->ctename, rte->ctename) == 0)
+ break;
+ ndx++;
+ }
+ if (lc == NULL) /* shouldn't happen */
+ elog(ERROR, "could not find CTE \"%s\"", rte->ctename);
+ if (ndx >= list_length(cteroot->cte_plan_ids))
+ elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
+ plan_id = list_nth_int(cteroot->cte_plan_ids, ndx);
+ Assert(plan_id > 0);
+ cteplan = (Plan *) list_nth(root->glob->subplans, plan_id - 1);
+
+ /* Mark rel with estimated output rows, width, etc */
+ set_cte_size_estimates(root, rel, cteplan);
+
+ /* Generate appropriate path */
+ add_path(rel, create_ctescan_path(root, rel));
+
+ /* Select cheapest path (pretty easy in this case...) */
+ set_cheapest(rel);
+}
+
+/*
+ * set_worktable_pathlist
+ * Build the (single) access path for a self-reference CTE RTE
+ */
+static void
+set_worktable_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
+{
+ Plan *cteplan;
+ PlannerInfo *cteroot;
+ Index levelsup;
+
+ /*
+ * We need to find the non-recursive term's plan, which is in the plan
+ * level that's processing the recursive UNION, which is one level
+ * *below* where the CTE comes from.
+ */
+ levelsup = rte->ctelevelsup;
+ if (levelsup == 0) /* shouldn't happen */
+ elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
+ levelsup--;
+ cteroot = root;
+ while (levelsup-- > 0)
+ {
+ cteroot = cteroot->parent_root;
+ if (!cteroot) /* shouldn't happen */
+ elog(ERROR, "bad levelsup for CTE \"%s\"", rte->ctename);
+ }
+ cteplan = cteroot->non_recursive_plan;
+ if (!cteplan) /* shouldn't happen */
+ elog(ERROR, "could not find plan for CTE \"%s\"", rte->ctename);
+
+ /* Mark rel with estimated output rows, width, etc */
+ set_cte_size_estimates(root, rel, cteplan);
+
+ /* Generate appropriate path */
+ add_path(rel, create_worktablescan_path(root, rel));
+
+ /* Select cheapest path (pretty easy in this case...) */
+ set_cheapest(rel);
+}
+
+/*
+ * make_rel_from_joinlist
+ * Build access paths using a "joinlist" to guide the join path search.
+ *
+ * See comments for deconstruct_jointree() for definition of the joinlist
+ * data structure.
+ */
+static RelOptInfo *
+make_rel_from_joinlist(PlannerInfo *root, List *joinlist)
{
int levels_needed;
- List *initial_rels = NIL;
- List *jt;
+ List *initial_rels;
+ ListCell *jl;
/*
- * Count the number of child jointree nodes. This is the depth of the
- * dynamic-programming algorithm we must employ to consider all ways
- * of joining the child nodes.
+ * Count the number of child joinlist nodes. This is the depth of the
+ * dynamic-programming algorithm we must employ to consider all ways of
+ * joining the child nodes.
*/
- levels_needed = length(from->fromlist);
+ levels_needed = list_length(joinlist);
if (levels_needed <= 0)
return NULL; /* nothing to do? */
/*
- * Construct a list of rels corresponding to the child jointree nodes.
+ * Construct a list of rels corresponding to the child joinlist nodes.
* This may contain both base rels and rels constructed according to
- * explicit JOIN directives.
+ * sub-joinlists.
*/
- foreach(jt, from->fromlist)
+ initial_rels = NIL;
+ foreach(jl, joinlist)
{
- Node *jtnode = (Node *) lfirst(jt);
+ Node *jlnode = (Node *) lfirst(jl);
+ RelOptInfo *thisrel;
- initial_rels = lappend(initial_rels,
- make_jointree_rel(root, jtnode));
+ if (IsA(jlnode, RangeTblRef))
+ {
+ int varno = ((RangeTblRef *) jlnode)->rtindex;
+
+ thisrel = find_base_rel(root, varno);
+ }
+ else if (IsA(jlnode, List))
+ {
+ /* Recurse to handle subproblem */
+ thisrel = make_rel_from_joinlist(root, (List *) jlnode);
+ }
+ else
+ {
+ elog(ERROR, "unrecognized joinlist node type: %d",
+ (int) nodeTag(jlnode));
+ thisrel = NULL; /* keep compiler quiet */
+ }
+
+ initial_rels = lappend(initial_rels, thisrel);
}
if (levels_needed == 1)
{
-
/*
- * Single jointree node, so we're done.
+ * Single joinlist node, so we're done.
*/
- return (RelOptInfo *) lfirst(initial_rels);
+ return (RelOptInfo *) linitial(initial_rels);
}
else
{
-
/*
* Consider the different orders in which we could join the rels,
- * using either GEQO or regular optimizer.
+ * using a plugin, GEQO, or the regular join search code.
+ *
+ * We put the initial_rels list into a PlannerInfo field because
+ * has_legal_joinclause() needs to look at it (ugly :-().
*/
- if (enable_geqo && levels_needed >= geqo_rels)
+ root->initial_rels = initial_rels;
+
+ if (join_search_hook)
+ return (*join_search_hook) (root, levels_needed, initial_rels);
+ else if (enable_geqo && levels_needed >= geqo_threshold)
return geqo(root, levels_needed, initial_rels);
else
- return make_one_rel_by_joins(root, levels_needed, initial_rels);
+ return standard_join_search(root, levels_needed, initial_rels);
}
}
/*
- * make_one_rel_by_joins
- * Find all possible joinpaths for a query by successively finding ways
+ * standard_join_search
+ * Find possible joinpaths for a query by successively finding ways
* to join component relations into join relations.
*
* 'levels_needed' is the number of iterations needed, ie, the number of
*
* 'initial_rels' is a list of RelOptInfo nodes for each independent
* jointree item. These are the components to be joined together.
+ * Note that levels_needed == list_length(initial_rels).
*
* Returns the final level of join relations, i.e., the relation that is
* the result of joining all the original relations together.
+ * At least one implementation path must be provided for this relation and
+ * all required sub-relations.
+ *
+ * To support loadable plugins that modify planner behavior by changing the
+ * join searching algorithm, we provide a hook variable that lets a plugin
+ * replace or supplement this function. Any such hook must return the same
+ * final join relation as the standard code would, but it might have a
+ * different set of implementation paths attached, and only the sub-joinrels
+ * needed for these paths need have been instantiated.
+ *
+ * Note to plugin authors: the functions invoked during standard_join_search()
+ * modify root->join_rel_list and root->join_rel_hash. If you want to do more
+ * than one join-order search, you'll probably need to save and restore the
+ * original states of those data structures. See geqo_eval() for an example.
*/
-static RelOptInfo *
-make_one_rel_by_joins(Query *root, int levels_needed, List *initial_rels)
+RelOptInfo *
+standard_join_search(PlannerInfo *root, int levels_needed, List *initial_rels)
{
List **joinitems;
int lev;
RelOptInfo *rel;
/*
- * We employ a simple "dynamic programming" algorithm: we first find
- * all ways to build joins of two jointree items, then all ways to
- * build joins of three items (from two-item joins and single items),
- * then four-item joins, and so on until we have considered all ways
- * to join all the items into one rel.
+ * We employ a simple "dynamic programming" algorithm: we first find all
+ * ways to build joins of two jointree items, then all ways to build joins
+ * of three items (from two-item joins and single items), then four-item
+ * joins, and so on until we have considered all ways to join all the
+ * items into one rel.
*
* joinitems[j] is a list of all the j-item rels. Initially we set
* joinitems[1] to represent all the single-jointree-item relations.
*/
- joinitems = (List **) palloc((levels_needed + 1) * sizeof(List *));
- MemSet(joinitems, 0, (levels_needed + 1) * sizeof(List *));
+ joinitems = (List **) palloc0((levels_needed + 1) * sizeof(List *));
joinitems[1] = initial_rels;
for (lev = 2; lev <= levels_needed; lev++)
{
- List *x;
+ ListCell *x;
/*
* Determine all possible pairs of relations to be joined at this
* level, and build paths for making each one from every available
* pair of lower-level relations.
*/
- joinitems[lev] = make_rels_by_joins(root, lev, joinitems);
+ joinitems[lev] = join_search_one_level(root, lev, joinitems);
/*
* Do cleanup work on each just-processed rel.
{
rel = (RelOptInfo *) lfirst(x);
-#ifdef NOT_USED
-
- /*
- * * for each expensive predicate in each path in each
- * distinct rel, * consider doing pullup -- JMH
- */
- if (XfuncMode != XFUNC_NOPULL && XfuncMode != XFUNC_OFF)
- xfunc_trypullup(rel);
-#endif
-
/* Find and save the cheapest paths for this rel */
set_cheapest(rel);
/*
* We should have a single rel at the final level.
*/
- Assert(length(joinitems[levels_needed]) == 1);
+ if (joinitems[levels_needed] == NIL)
+ elog(ERROR, "failed to build any %d-way joins", levels_needed);
+ Assert(list_length(joinitems[levels_needed]) == 1);
- rel = (RelOptInfo *) lfirst(joinitems[levels_needed]);
+ rel = (RelOptInfo *) linitial(joinitems[levels_needed]);
return rel;
}
/*****************************************************************************
+ * PUSHING QUALS DOWN INTO SUBQUERIES
+ *****************************************************************************/
+
+/*
+ * subquery_is_pushdown_safe - is a subquery safe for pushing down quals?
+ *
+ * subquery is the particular component query being checked. topquery
+ * is the top component of a set-operations tree (the same Query if no
+ * set-op is involved).
+ *
+ * Conditions checked here:
+ *
+ * 1. If the subquery has a LIMIT clause, we must not push down any quals,
+ * since that could change the set of rows returned.
+ *
+ * 2. If the subquery contains EXCEPT or EXCEPT ALL set ops we cannot push
+ * quals into it, because that would change the results.
+ *
+ * 3. For subqueries using UNION/UNION ALL/INTERSECT/INTERSECT ALL, we can
+ * push quals into each component query, but the quals can only reference
+ * subquery columns that suffer no type coercions in the set operation.
+ * Otherwise there are possible semantic gotchas. So, we check the
+ * component queries to see if any of them have different output types;
+ * differentTypes[k] is set true if column k has different type in any
+ * component.
+ */
+static bool
+subquery_is_pushdown_safe(Query *subquery, Query *topquery,
+ bool *differentTypes)
+{
+ SetOperationStmt *topop;
+
+ /* Check point 1 */
+ if (subquery->limitOffset != NULL || subquery->limitCount != NULL)
+ return false;
+
+ /* Are we at top level, or looking at a setop component? */
+ if (subquery == topquery)
+ {
+ /* Top level, so check any component queries */
+ if (subquery->setOperations != NULL)
+ if (!recurse_pushdown_safe(subquery->setOperations, topquery,
+ differentTypes))
+ return false;
+ }
+ else
+ {
+ /* Setop component must not have more components (too weird) */
+ if (subquery->setOperations != NULL)
+ return false;
+ /* Check whether setop component output types match top level */
+ topop = (SetOperationStmt *) topquery->setOperations;
+ Assert(topop && IsA(topop, SetOperationStmt));
+ compare_tlist_datatypes(subquery->targetList,
+ topop->colTypes,
+ differentTypes);
+ }
+ return true;
+}
+
+/*
+ * Helper routine to recurse through setOperations tree
+ */
+static bool
+recurse_pushdown_safe(Node *setOp, Query *topquery,
+ bool *differentTypes)
+{
+ if (IsA(setOp, RangeTblRef))
+ {
+ RangeTblRef *rtr = (RangeTblRef *) setOp;
+ RangeTblEntry *rte = rt_fetch(rtr->rtindex, topquery->rtable);
+ Query *subquery = rte->subquery;
+
+ Assert(subquery != NULL);
+ return subquery_is_pushdown_safe(subquery, topquery, differentTypes);
+ }
+ else if (IsA(setOp, SetOperationStmt))
+ {
+ SetOperationStmt *op = (SetOperationStmt *) setOp;
+
+ /* EXCEPT is no good */
+ if (op->op == SETOP_EXCEPT)
+ return false;
+ /* Else recurse */
+ if (!recurse_pushdown_safe(op->larg, topquery, differentTypes))
+ return false;
+ if (!recurse_pushdown_safe(op->rarg, topquery, differentTypes))
+ return false;
+ }
+ else
+ {
+ elog(ERROR, "unrecognized node type: %d",
+ (int) nodeTag(setOp));
+ }
+ return true;
+}
+
+/*
+ * Compare tlist's datatypes against the list of set-operation result types.
+ * For any items that are different, mark the appropriate element of
+ * differentTypes[] to show that this column will have type conversions.
+ *
+ * We don't have to care about typmods here: the only allowed difference
+ * between set-op input and output typmods is input is a specific typmod
+ * and output is -1, and that does not require a coercion.
+ */
+static void
+compare_tlist_datatypes(List *tlist, List *colTypes,
+ bool *differentTypes)
+{
+ ListCell *l;
+ ListCell *colType = list_head(colTypes);
+
+ foreach(l, tlist)
+ {
+ TargetEntry *tle = (TargetEntry *) lfirst(l);
+
+ if (tle->resjunk)
+ continue; /* ignore resjunk columns */
+ if (colType == NULL)
+ elog(ERROR, "wrong number of tlist entries");
+ if (exprType((Node *) tle->expr) != lfirst_oid(colType))
+ differentTypes[tle->resno] = true;
+ colType = lnext(colType);
+ }
+ if (colType != NULL)
+ elog(ERROR, "wrong number of tlist entries");
+}
+
+/*
+ * qual_is_pushdown_safe - is a particular qual safe to push down?
+ *
+ * qual is a restriction clause applying to the given subquery (whose RTE
+ * has index rti in the parent query).
+ *
+ * Conditions checked here:
+ *
+ * 1. The qual must not contain any subselects (mainly because I'm not sure
+ * it will work correctly: sublinks will already have been transformed into
+ * subplans in the qual, but not in the subquery).
+ *
+ * 2. The qual must not refer to the whole-row output of the subquery
+ * (since there is no easy way to name that within the subquery itself).
+ *
+ * 3. The qual must not refer to any subquery output columns that were
+ * found to have inconsistent types across a set operation tree by
+ * subquery_is_pushdown_safe().
+ *
+ * 4. If the subquery uses DISTINCT ON, we must not push down any quals that
+ * refer to non-DISTINCT output columns, because that could change the set
+ * of rows returned. (This condition is vacuous for DISTINCT, because then
+ * there are no non-DISTINCT output columns, so we needn't check. But note
+ * we are assuming that the qual can't distinguish values that the DISTINCT
+ * operator sees as equal. This is a bit shaky but we have no way to test
+ * for the case, and it's unlikely enough that we shouldn't refuse the
+ * optimization just because it could theoretically happen.)
*
+ * 5. We must not push down any quals that refer to subselect outputs that
+ * return sets, else we'd introduce functions-returning-sets into the
+ * subquery's WHERE/HAVING quals.
+ *
+ * 6. We must not push down any quals that refer to subselect outputs that
+ * contain volatile functions, for fear of introducing strange results due
+ * to multiple evaluation of a volatile function.
+ */
+static bool
+qual_is_pushdown_safe(Query *subquery, Index rti, Node *qual,
+ bool *differentTypes)
+{
+ bool safe = true;
+ List *vars;
+ ListCell *vl;
+ Bitmapset *tested = NULL;
+
+ /* Refuse subselects (point 1) */
+ if (contain_subplans(qual))
+ return false;
+
+ /*
+ * Examine all Vars used in clause; since it's a restriction clause, all
+ * such Vars must refer to subselect output columns.
+ */
+ vars = pull_var_clause(qual, true);
+ foreach(vl, vars)
+ {
+ Var *var = (Var *) lfirst(vl);
+ TargetEntry *tle;
+
+ /*
+ * XXX Punt if we find any PlaceHolderVars in the restriction clause.
+ * It's not clear whether a PHV could safely be pushed down, and even
+ * less clear whether such a situation could arise in any cases of
+ * practical interest anyway. So for the moment, just refuse to push
+ * down.
+ */
+ if (!IsA(var, Var))
+ {
+ safe = false;
+ break;
+ }
+
+ Assert(var->varno == rti);
+
+ /* Check point 2 */
+ if (var->varattno == 0)
+ {
+ safe = false;
+ break;
+ }
+
+ /*
+ * We use a bitmapset to avoid testing the same attno more than once.
+ * (NB: this only works because subquery outputs can't have negative
+ * attnos.)
+ */
+ if (bms_is_member(var->varattno, tested))
+ continue;
+ tested = bms_add_member(tested, var->varattno);
+
+ /* Check point 3 */
+ if (differentTypes[var->varattno])
+ {
+ safe = false;
+ break;
+ }
+
+ /* Must find the tlist element referenced by the Var */
+ tle = get_tle_by_resno(subquery->targetList, var->varattno);
+ Assert(tle != NULL);
+ Assert(!tle->resjunk);
+
+ /* If subquery uses DISTINCT ON, check point 4 */
+ if (subquery->hasDistinctOn &&
+ !targetIsInSortList(tle, InvalidOid, subquery->distinctClause))
+ {
+ /* non-DISTINCT column, so fail */
+ safe = false;
+ break;
+ }
+
+ /* Refuse functions returning sets (point 5) */
+ if (expression_returns_set((Node *) tle->expr))
+ {
+ safe = false;
+ break;
+ }
+
+ /* Refuse volatile functions (point 6) */
+ if (contain_volatile_functions((Node *) tle->expr))
+ {
+ safe = false;
+ break;
+ }
+ }
+
+ list_free(vars);
+ bms_free(tested);
+
+ return safe;
+}
+
+/*
+ * subquery_push_qual - push down a qual that we have determined is safe
+ */
+static void
+subquery_push_qual(Query *subquery, RangeTblEntry *rte, Index rti, Node *qual)
+{
+ if (subquery->setOperations != NULL)
+ {
+ /* Recurse to push it separately to each component query */
+ recurse_push_qual(subquery->setOperations, subquery,
+ rte, rti, qual);
+ }
+ else
+ {
+ /*
+ * We need to replace Vars in the qual (which must refer to outputs of
+ * the subquery) with copies of the subquery's targetlist expressions.
+ * Note that at this point, any uplevel Vars in the qual should have
+ * been replaced with Params, so they need no work.
+ *
+ * This step also ensures that when we are pushing into a setop tree,
+ * each component query gets its own copy of the qual.
+ */
+ qual = ResolveNew(qual, rti, 0, rte,
+ subquery->targetList,
+ CMD_SELECT, 0);
+
+ /*
+ * Now attach the qual to the proper place: normally WHERE, but if the
+ * subquery uses grouping or aggregation, put it in HAVING (since the
+ * qual really refers to the group-result rows).
+ */
+ if (subquery->hasAggs || subquery->groupClause || subquery->havingQual)
+ subquery->havingQual = make_and_qual(subquery->havingQual, qual);
+ else
+ subquery->jointree->quals =
+ make_and_qual(subquery->jointree->quals, qual);
+
+ /*
+ * We need not change the subquery's hasAggs or hasSublinks flags,
+ * since we can't be pushing down any aggregates that weren't there
+ * before, and we don't push down subselects at all.
+ */
+ }
+}
+
+/*
+ * Helper routine to recurse through setOperations tree
+ */
+static void
+recurse_push_qual(Node *setOp, Query *topquery,
+ RangeTblEntry *rte, Index rti, Node *qual)
+{
+ if (IsA(setOp, RangeTblRef))
+ {
+ RangeTblRef *rtr = (RangeTblRef *) setOp;
+ RangeTblEntry *subrte = rt_fetch(rtr->rtindex, topquery->rtable);
+ Query *subquery = subrte->subquery;
+
+ Assert(subquery != NULL);
+ subquery_push_qual(subquery, rte, rti, qual);
+ }
+ else if (IsA(setOp, SetOperationStmt))
+ {
+ SetOperationStmt *op = (SetOperationStmt *) setOp;
+
+ recurse_push_qual(op->larg, topquery, rte, rti, qual);
+ recurse_push_qual(op->rarg, topquery, rte, rti, qual);
+ }
+ else
+ {
+ elog(ERROR, "unrecognized node type: %d",
+ (int) nodeTag(setOp));
+ }
+}
+
+/*****************************************************************************
+ * DEBUG SUPPORT
*****************************************************************************/
#ifdef OPTIMIZER_DEBUG
static void
-print_joinclauses(Query *root, List *clauses)
+print_relids(Relids relids)
{
- List *l;
- extern void print_expr(Node *expr, List *rtable); /* in print.c */
+ Relids tmprelids;
+ int x;
+ bool first = true;
+
+ tmprelids = bms_copy(relids);
+ while ((x = bms_first_member(tmprelids)) >= 0)
+ {
+ if (!first)
+ printf(" ");
+ printf("%d", x);
+ first = false;
+ }
+ bms_free(tmprelids);
+}
+
+static void
+print_restrictclauses(PlannerInfo *root, List *clauses)
+{
+ ListCell *l;
foreach(l, clauses)
{
RestrictInfo *c = lfirst(l);
- print_expr((Node *) c->clause, root->rtable);
+ print_expr((Node *) c->clause, root->parse->rtable);
if (lnext(l))
- printf(" ");
+ printf(", ");
}
}
static void
-print_path(Query *root, Path *path, int indent)
+print_path(PlannerInfo *root, Path *path, int indent)
{
- char *ptype = NULL;
- JoinPath *jp;
+ const char *ptype;
bool join = false;
+ Path *subpath = NULL;
int i;
- for (i = 0; i < indent; i++)
- printf("\t");
-
switch (nodeTag(path))
{
case T_Path:
ptype = "SeqScan";
- join = false;
break;
case T_IndexPath:
ptype = "IdxScan";
- join = false;
+ break;
+ case T_BitmapHeapPath:
+ ptype = "BitmapHeapScan";
+ break;
+ case T_BitmapAndPath:
+ ptype = "BitmapAndPath";
+ break;
+ case T_BitmapOrPath:
+ ptype = "BitmapOrPath";
+ break;
+ case T_TidPath:
+ ptype = "TidScan";
+ break;
+ case T_AppendPath:
+ ptype = "Append";
+ break;
+ case T_ResultPath:
+ ptype = "Result";
+ break;
+ case T_MaterialPath:
+ ptype = "Material";
+ subpath = ((MaterialPath *) path)->subpath;
+ break;
+ case T_UniquePath:
+ ptype = "Unique";
+ subpath = ((UniquePath *) path)->subpath;
break;
case T_NestPath:
- ptype = "Nestloop";
+ ptype = "NestLoop";
join = true;
break;
case T_MergePath:
join = true;
break;
default:
+ ptype = "???Path";
break;
}
+
+ for (i = 0; i < indent; i++)
+ printf("\t");
+ printf("%s", ptype);
+
+ if (path->parent)
+ {
+ printf("(");
+ print_relids(path->parent->relids);
+ printf(") rows=%.0f", path->parent->rows);
+ }
+ printf(" cost=%.2f..%.2f\n", path->startup_cost, path->total_cost);
+
+ if (path->pathkeys)
+ {
+ for (i = 0; i < indent; i++)
+ printf("\t");
+ printf(" pathkeys: ");
+ print_pathkeys(path->pathkeys, root->parse->rtable);
+ }
+
if (join)
{
- jp = (JoinPath *) path;
+ JoinPath *jp = (JoinPath *) path;
- printf("%s rows=%.0f cost=%.2f..%.2f\n",
- ptype, path->parent->rows,
- path->startup_cost, path->total_cost);
+ for (i = 0; i < indent; i++)
+ printf("\t");
+ printf(" clauses: ");
+ print_restrictclauses(root, jp->joinrestrictinfo);
+ printf("\n");
- if (path->pathkeys)
+ if (IsA(path, MergePath))
{
- for (i = 0; i < indent; i++)
- printf("\t");
- printf(" pathkeys=");
- print_pathkeys(path->pathkeys, root->rtable);
- }
+ MergePath *mp = (MergePath *) path;
- switch (nodeTag(path))
- {
- case T_MergePath:
- case T_HashPath:
+ if (mp->outersortkeys || mp->innersortkeys)
+ {
for (i = 0; i < indent; i++)
printf("\t");
- printf(" clauses=(");
- print_joinclauses(root, jp->joinrestrictinfo);
- printf(")\n");
-
- if (nodeTag(path) == T_MergePath)
- {
- MergePath *mp = (MergePath *) path;
-
- if (mp->outersortkeys || mp->innersortkeys)
- {
- for (i = 0; i < indent; i++)
- printf("\t");
- printf(" sortouter=%d sortinner=%d\n",
- ((mp->outersortkeys) ? 1 : 0),
- ((mp->innersortkeys) ? 1 : 0));
- }
- }
- break;
- default:
- break;
+ printf(" sortouter=%d sortinner=%d\n",
+ ((mp->outersortkeys) ? 1 : 0),
+ ((mp->innersortkeys) ? 1 : 0));
+ }
}
+
print_path(root, jp->outerjoinpath, indent + 1);
print_path(root, jp->innerjoinpath, indent + 1);
}
- else
- {
- int relid = lfirsti(path->parent->relids);
- printf("%s(%d) rows=%.0f cost=%.2f..%.2f\n",
- ptype, relid, path->parent->rows,
- path->startup_cost, path->total_cost);
-
- if (path->pathkeys)
- {
- for (i = 0; i < indent; i++)
- printf("\t");
- printf(" pathkeys=");
- print_pathkeys(path->pathkeys, root->rtable);
- }
- }
+ if (subpath)
+ print_path(root, subpath, indent + 1);
}
-static void
-debug_print_rel(Query *root, RelOptInfo *rel)
+void
+debug_print_rel(PlannerInfo *root, RelOptInfo *rel)
{
- List *l;
+ ListCell *l;
- printf("(");
- foreach(l, rel->relids)
- printf("%d ", lfirsti(l));
+ printf("RELOPTINFO (");
+ print_relids(rel->relids);
printf("): rows=%.0f width=%d\n", rel->rows, rel->width);
+ if (rel->baserestrictinfo)
+ {
+ printf("\tbaserestrictinfo: ");
+ print_restrictclauses(root, rel->baserestrictinfo);
+ printf("\n");
+ }
+
+ if (rel->joininfo)
+ {
+ printf("\tjoininfo: ");
+ print_restrictclauses(root, rel->joininfo);
+ printf("\n");
+ }
+
printf("\tpath list:\n");
foreach(l, rel->pathlist)
print_path(root, lfirst(l), 1);
print_path(root, rel->cheapest_startup_path, 1);
printf("\n\tcheapest total path:\n");
print_path(root, rel->cheapest_total_path, 1);
+ printf("\n");
+ fflush(stdout);
}
-#endif /* OPTIMIZER_DEBUG */
+#endif /* OPTIMIZER_DEBUG */
projects / postgresql / blobdiff