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PostgreSQL/src/backend/optimizer/plan/setrefs.c
Tom Lane 69c430626b Track tlist_vinfo.varnullingrels even in non-Assert builds. 
Oversight in commit 867be9c07 (which should get reverted
along with that, if we ever do revert it).  Per buildfarm.
2023-05-17 11:46:15 -04:00

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/*-------------------------------------------------------------------------
*
* setrefs.c
* Post-processing of a completed plan tree: fix references to subplan
* vars, compute regproc values for operators, etc
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* src/backend/optimizer/plan/setrefs.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "access/transam.h"
#include "catalog/pg_type.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "optimizer/optimizer.h"
#include "optimizer/pathnode.h"
#include "optimizer/planmain.h"
#include "optimizer/planner.h"
#include "optimizer/tlist.h"
#include "parser/parse_relation.h"
#include "tcop/utility.h"
#include "utils/lsyscache.h"
#include "utils/syscache.h"
typedef enum
{
NRM_EQUAL, /* expect exact match of nullingrels */
NRM_SUBSET, /* actual Var may have a subset of input */
NRM_SUPERSET /* actual Var may have a superset of input */
} NullingRelsMatch;
typedef struct
{
int varno; /* RT index of Var */
AttrNumber varattno; /* attr number of Var */
AttrNumber resno; /* TLE position of Var */
Bitmapset *varnullingrels; /* Var's varnullingrels */
} tlist_vinfo;
typedef struct
{
List *tlist; /* underlying target list */
int num_vars; /* number of plain Var tlist entries */
bool has_ph_vars; /* are there PlaceHolderVar entries? */
bool has_non_vars; /* are there other entries? */
tlist_vinfo vars[FLEXIBLE_ARRAY_MEMBER]; /* has num_vars entries */
} indexed_tlist;
typedef struct
{
PlannerInfo *root;
int rtoffset;
double num_exec;
} fix_scan_expr_context;
typedef struct
{
PlannerInfo *root;
indexed_tlist *outer_itlist;
indexed_tlist *inner_itlist;
Index acceptable_rel;
int rtoffset;
NullingRelsMatch nrm_match;
double num_exec;
} fix_join_expr_context;
typedef struct
{
PlannerInfo *root;
indexed_tlist *subplan_itlist;
int newvarno;
int rtoffset;
NullingRelsMatch nrm_match;
double num_exec;
} fix_upper_expr_context;
typedef struct
{
PlannerInfo *root;
indexed_tlist *subplan_itlist;
int newvarno;
} fix_windowagg_cond_context;
/* Context info for flatten_rtes_walker() */
typedef struct
{
PlannerGlobal *glob;
Query *query;
} flatten_rtes_walker_context;
/*
* Selecting the best alternative in an AlternativeSubPlan expression requires
* estimating how many times that expression will be evaluated. For an
* expression in a plan node's targetlist, the plan's estimated number of
* output rows is clearly what to use, but for an expression in a qual it's
* far less clear. Since AlternativeSubPlans aren't heavily used, we don't
* want to expend a lot of cycles making such estimates. What we use is twice
* the number of output rows. That's not entirely unfounded: we know that
* clause_selectivity() would fall back to a default selectivity estimate
* of 0.5 for any SubPlan, so if the qual containing the SubPlan is the last
* to be applied (which it likely would be, thanks to order_qual_clauses()),
* this matches what we could have estimated in a far more laborious fashion.
* Obviously there are many other scenarios, but it's probably not worth the
* trouble to try to improve on this estimate, especially not when we don't
* have a better estimate for the selectivity of the SubPlan qual itself.
*/
#define NUM_EXEC_TLIST(parentplan) ((parentplan)->plan_rows)
#define NUM_EXEC_QUAL(parentplan) ((parentplan)->plan_rows * 2.0)
/*
* Check if a Const node is a regclass value. We accept plain OID too,
* since a regclass Const will get folded to that type if it's an argument
* to oideq or similar operators. (This might result in some extraneous
* values in a plan's list of relation dependencies, but the worst result
* would be occasional useless replans.)
*/
#define ISREGCLASSCONST(con) \
(((con)->consttype == REGCLASSOID || (con)->consttype == OIDOID) && \
!(con)->constisnull)
#define fix_scan_list(root, lst, rtoffset, num_exec) \
((List *) fix_scan_expr(root, (Node *) (lst), rtoffset, num_exec))
static void add_rtes_to_flat_rtable(PlannerInfo *root, bool recursing);
static void flatten_unplanned_rtes(PlannerGlobal *glob, RangeTblEntry *rte);
static bool flatten_rtes_walker(Node *node, flatten_rtes_walker_context *cxt);
static void add_rte_to_flat_rtable(PlannerGlobal *glob, List *rteperminfos,
RangeTblEntry *rte);
static Plan *set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset);
static Plan *set_indexonlyscan_references(PlannerInfo *root,
IndexOnlyScan *plan,
int rtoffset);
static Plan *set_subqueryscan_references(PlannerInfo *root,
SubqueryScan *plan,
int rtoffset);
static Plan *clean_up_removed_plan_level(Plan *parent, Plan *child);
static void set_foreignscan_references(PlannerInfo *root,
ForeignScan *fscan,
int rtoffset);
static void set_customscan_references(PlannerInfo *root,
CustomScan *cscan,
int rtoffset);
static Plan *set_append_references(PlannerInfo *root,
Append *aplan,
int rtoffset);
static Plan *set_mergeappend_references(PlannerInfo *root,
MergeAppend *mplan,
int rtoffset);
static void set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset);
static Relids offset_relid_set(Relids relids, int rtoffset);
static Node *fix_scan_expr(PlannerInfo *root, Node *node,
int rtoffset, double num_exec);
static Node *fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context);
static bool fix_scan_expr_walker(Node *node, fix_scan_expr_context *context);
static void set_join_references(PlannerInfo *root, Join *join, int rtoffset);
static void set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset);
static void set_param_references(PlannerInfo *root, Plan *plan);
static Node *convert_combining_aggrefs(Node *node, void *context);
static void set_dummy_tlist_references(Plan *plan, int rtoffset);
static indexed_tlist *build_tlist_index(List *tlist);
static Var *search_indexed_tlist_for_var(Var *var,
indexed_tlist *itlist,
int newvarno,
int rtoffset,
NullingRelsMatch nrm_match);
static Var *search_indexed_tlist_for_phv(PlaceHolderVar *phv,
indexed_tlist *itlist,
int newvarno,
NullingRelsMatch nrm_match);
static Var *search_indexed_tlist_for_non_var(Expr *node,
indexed_tlist *itlist,
int newvarno);
static Var *search_indexed_tlist_for_sortgroupref(Expr *node,
Index sortgroupref,
indexed_tlist *itlist,
int newvarno);
static List *fix_join_expr(PlannerInfo *root,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index acceptable_rel,
int rtoffset,
NullingRelsMatch nrm_match,
double num_exec);
static Node *fix_join_expr_mutator(Node *node,
fix_join_expr_context *context);
static Node *fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
int newvarno,
int rtoffset,
NullingRelsMatch nrm_match,
double num_exec);
static Node *fix_upper_expr_mutator(Node *node,
fix_upper_expr_context *context);
static List *set_returning_clause_references(PlannerInfo *root,
List *rlist,
Plan *topplan,
Index resultRelation,
int rtoffset);
static List *set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan);
/*****************************************************************************
*
* SUBPLAN REFERENCES
*
*****************************************************************************/
/*
* set_plan_references
*
* This is the final processing pass of the planner/optimizer. The plan
* tree is complete; we just have to adjust some representational details
* for the convenience of the executor:
*
* 1. We flatten the various subquery rangetables into a single list, and
* zero out RangeTblEntry fields that are not useful to the executor.
*
* 2. We adjust Vars in scan nodes to be consistent with the flat rangetable.
*
* 3. We adjust Vars in upper plan nodes to refer to the outputs of their
* subplans.
*
* 4. Aggrefs in Agg plan nodes need to be adjusted in some cases involving
* partial aggregation or minmax aggregate optimization.
*
* 5. PARAM_MULTIEXPR Params are replaced by regular PARAM_EXEC Params,
* now that we have finished planning all MULTIEXPR subplans.
*
* 6. AlternativeSubPlan expressions are replaced by just one of their
* alternatives, using an estimate of how many times they'll be executed.
*
* 7. We compute regproc OIDs for operators (ie, we look up the function
* that implements each op).
*
* 8. We create lists of specific objects that the plan depends on.
* This will be used by plancache.c to drive invalidation of cached plans.
* Relation dependencies are represented by OIDs, and everything else by
* PlanInvalItems (this distinction is motivated by the shared-inval APIs).
* Currently, relations, user-defined functions, and domains are the only
* types of objects that are explicitly tracked this way.
*
* 9. We assign every plan node in the tree a unique ID.
*
* We also perform one final optimization step, which is to delete
* SubqueryScan, Append, and MergeAppend plan nodes that aren't doing
* anything useful. The reason for doing this last is that
* it can't readily be done before set_plan_references, because it would
* break set_upper_references: the Vars in the child plan's top tlist
* wouldn't match up with the Vars in the outer plan tree. A SubqueryScan
* serves a necessary function as a buffer between outer query and subquery
* variable numbering ... but after we've flattened the rangetable this is
* no longer a problem, since then there's only one rtindex namespace.
* Likewise, Append and MergeAppend buffer between the parent and child vars
* of an appendrel, but we don't need to worry about that once we've done
* set_plan_references.
*
* set_plan_references recursively traverses the whole plan tree.
*
* The return value is normally the same Plan node passed in, but can be
* different when the passed-in Plan is a node we decide isn't needed.
*
* The flattened rangetable entries are appended to root->glob->finalrtable.
* Also, rowmarks entries are appended to root->glob->finalrowmarks, and the
* RT indexes of ModifyTable result relations to root->glob->resultRelations,
* and flattened AppendRelInfos are appended to root->glob->appendRelations.
* Plan dependencies are appended to root->glob->relationOids (for relations)
* and root->glob->invalItems (for everything else).
*
* Notice that we modify Plan nodes in-place, but use expression_tree_mutator
* to process targetlist and qual expressions. We can assume that the Plan
* nodes were just built by the planner and are not multiply referenced, but
* it's not so safe to assume that for expression tree nodes.
*/
Plan *
set_plan_references(PlannerInfo *root, Plan *plan)
{
Plan *result;
PlannerGlobal *glob = root->glob;
int rtoffset = list_length(glob->finalrtable);
ListCell *lc;
/*
* Add all the query's RTEs to the flattened rangetable. The live ones
* will have their rangetable indexes increased by rtoffset. (Additional
* RTEs, not referenced by the Plan tree, might get added after those.)
*/
add_rtes_to_flat_rtable(root, false);
/*
* Adjust RT indexes of PlanRowMarks and add to final rowmarks list
*/
foreach(lc, root->rowMarks)
{
PlanRowMark *rc = lfirst_node(PlanRowMark, lc);
PlanRowMark *newrc;
/* flat copy is enough since all fields are scalars */
newrc = (PlanRowMark *) palloc(sizeof(PlanRowMark));
memcpy(newrc, rc, sizeof(PlanRowMark));
/* adjust indexes ... but *not* the rowmarkId */
newrc->rti += rtoffset;
newrc->prti += rtoffset;
glob->finalrowmarks = lappend(glob->finalrowmarks, newrc);
}
/*
* Adjust RT indexes of AppendRelInfos and add to final appendrels list.
* We assume the AppendRelInfos were built during planning and don't need
* to be copied.
*/
foreach(lc, root->append_rel_list)
{
AppendRelInfo *appinfo = lfirst_node(AppendRelInfo, lc);
/* adjust RT indexes */
appinfo->parent_relid += rtoffset;
appinfo->child_relid += rtoffset;
/*
* Rather than adjust the translated_vars entries, just drop 'em.
* Neither the executor nor EXPLAIN currently need that data.
*/
appinfo->translated_vars = NIL;
glob->appendRelations = lappend(glob->appendRelations, appinfo);
}
/* If needed, create workspace for processing AlternativeSubPlans */
if (root->hasAlternativeSubPlans)
{
root->isAltSubplan = (bool *)
palloc0(list_length(glob->subplans) * sizeof(bool));
root->isUsedSubplan = (bool *)
palloc0(list_length(glob->subplans) * sizeof(bool));
}
/* Now fix the Plan tree */
result = set_plan_refs(root, plan, rtoffset);
/*
* If we have AlternativeSubPlans, it is likely that we now have some
* unreferenced subplans in glob->subplans. To avoid expending cycles on
* those subplans later, get rid of them by setting those list entries to
* NULL. (Note: we can't do this immediately upon processing an
* AlternativeSubPlan, because there may be multiple copies of the
* AlternativeSubPlan, and they can get resolved differently.)
*/
if (root->hasAlternativeSubPlans)
{
foreach(lc, glob->subplans)
{
int ndx = foreach_current_index(lc);
/*
* If it was used by some AlternativeSubPlan in this query level,
* but wasn't selected as best by any AlternativeSubPlan, then we
* don't need it. Do not touch subplans that aren't parts of
* AlternativeSubPlans.
*/
if (root->isAltSubplan[ndx] && !root->isUsedSubplan[ndx])
lfirst(lc) = NULL;
}
}
return result;
}
/*
* Extract RangeTblEntries from the plan's rangetable, and add to flat rtable
*
* This can recurse into subquery plans; "recursing" is true if so.
*
* This also seems like a good place to add the query's RTEPermissionInfos to
* the flat rteperminfos.
*/
static void
add_rtes_to_flat_rtable(PlannerInfo *root, bool recursing)
{
PlannerGlobal *glob = root->glob;
Index rti;
ListCell *lc;
/*
* Add the query's own RTEs to the flattened rangetable.
*
* At top level, we must add all RTEs so that their indexes in the
* flattened rangetable match up with their original indexes. When
* recursing, we only care about extracting relation RTEs (and subquery
* RTEs that were once relation RTEs).
*/
foreach(lc, root->parse->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
if (!recursing || rte->rtekind == RTE_RELATION ||
(rte->rtekind == RTE_SUBQUERY && OidIsValid(rte->relid)))
add_rte_to_flat_rtable(glob, root->parse->rteperminfos, rte);
}
/*
* If there are any dead subqueries, they are not referenced in the Plan
* tree, so we must add RTEs contained in them to the flattened rtable
* separately. (If we failed to do this, the executor would not perform
* expected permission checks for tables mentioned in such subqueries.)
*
* Note: this pass over the rangetable can't be combined with the previous
* one, because that would mess up the numbering of the live RTEs in the
* flattened rangetable.
*/
rti = 1;
foreach(lc, root->parse->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
/*
* We should ignore inheritance-parent RTEs: their contents have been
* pulled up into our rangetable already. Also ignore any subquery
* RTEs without matching RelOptInfos, as they likewise have been
* pulled up.
*/
if (rte->rtekind == RTE_SUBQUERY && !rte->inh &&
rti < root->simple_rel_array_size)
{
RelOptInfo *rel = root->simple_rel_array[rti];
if (rel != NULL)
{
Assert(rel->relid == rti); /* sanity check on array */
/*
* The subquery might never have been planned at all, if it
* was excluded on the basis of self-contradictory constraints
* in our query level. In this case apply
* flatten_unplanned_rtes.
*
* If it was planned but the result rel is dummy, we assume
* that it has been omitted from our plan tree (see
* set_subquery_pathlist), and recurse to pull up its RTEs.
*
* Otherwise, it should be represented by a SubqueryScan node
* somewhere in our plan tree, and we'll pull up its RTEs when
* we process that plan node.
*
* However, if we're recursing, then we should pull up RTEs
* whether the subquery is dummy or not, because we've found
* that some upper query level is treating this one as dummy,
* and so we won't scan this level's plan tree at all.
*/
if (rel->subroot == NULL)
flatten_unplanned_rtes(glob, rte);
else if (recursing ||
IS_DUMMY_REL(fetch_upper_rel(rel->subroot,
UPPERREL_FINAL, NULL)))
add_rtes_to_flat_rtable(rel->subroot, true);
}
}
rti++;
}
}
/*
* Extract RangeTblEntries from a subquery that was never planned at all
*/
static void
flatten_unplanned_rtes(PlannerGlobal *glob, RangeTblEntry *rte)
{
flatten_rtes_walker_context cxt = {glob, rte->subquery};
/* Use query_tree_walker to find all RTEs in the parse tree */
(void) query_tree_walker(rte->subquery,
flatten_rtes_walker,
(void *) &cxt,
QTW_EXAMINE_RTES_BEFORE);
}
static bool
flatten_rtes_walker(Node *node, flatten_rtes_walker_context *cxt)
{
if (node == NULL)
return false;
if (IsA(node, RangeTblEntry))
{
RangeTblEntry *rte = (RangeTblEntry *) node;
/* As above, we need only save relation RTEs and former relations */
if (rte->rtekind == RTE_RELATION ||
(rte->rtekind == RTE_SUBQUERY && OidIsValid(rte->relid)))
add_rte_to_flat_rtable(cxt->glob, cxt->query->rteperminfos, rte);
return false;
}
if (IsA(node, Query))
{
/*
* Recurse into subselects. Must update cxt->query to this query so
* that the rtable and rteperminfos correspond with each other.
*/
Query *save_query = cxt->query;
bool result;
cxt->query = (Query *) node;
result = query_tree_walker((Query *) node,
flatten_rtes_walker,
(void *) cxt,
QTW_EXAMINE_RTES_BEFORE);
cxt->query = save_query;
return result;
}
return expression_tree_walker(node, flatten_rtes_walker,
(void *) cxt);
}
/*
* Add (a copy of) the given RTE to the final rangetable and also the
* corresponding RTEPermissionInfo, if any, to final rteperminfos.
*
* In the flat rangetable, we zero out substructure pointers that are not
* needed by the executor; this reduces the storage space and copying cost
* for cached plans. We keep only the ctename, alias, eref Alias fields,
* which are needed by EXPLAIN, and perminfoindex which is needed by the
* executor to fetch the RTE's RTEPermissionInfo.
*/
static void
add_rte_to_flat_rtable(PlannerGlobal *glob, List *rteperminfos,
RangeTblEntry *rte)
{
RangeTblEntry *newrte;
/* flat copy to duplicate all the scalar fields */
newrte = (RangeTblEntry *) palloc(sizeof(RangeTblEntry));
memcpy(newrte, rte, sizeof(RangeTblEntry));
/* zap unneeded sub-structure */
newrte->tablesample = NULL;
newrte->subquery = NULL;
newrte->joinaliasvars = NIL;
newrte->joinleftcols = NIL;
newrte->joinrightcols = NIL;
newrte->join_using_alias = NULL;
newrte->functions = NIL;
newrte->tablefunc = NULL;
newrte->values_lists = NIL;
newrte->coltypes = NIL;
newrte->coltypmods = NIL;
newrte->colcollations = NIL;
newrte->securityQuals = NIL;
glob->finalrtable = lappend(glob->finalrtable, newrte);
/*
* If it's a plain relation RTE (or a subquery that was once a view
* reference), add the relation OID to relationOids.
*
* We do this even though the RTE might be unreferenced in the plan tree;
* this would correspond to cases such as views that were expanded, child
* tables that were eliminated by constraint exclusion, etc. Schema
* invalidation on such a rel must still force rebuilding of the plan.
*
* Note we don't bother to avoid making duplicate list entries. We could,
* but it would probably cost more cycles than it would save.
*/
if (newrte->rtekind == RTE_RELATION ||
(newrte->rtekind == RTE_SUBQUERY && OidIsValid(newrte->relid)))
glob->relationOids = lappend_oid(glob->relationOids, newrte->relid);
/*
* Add a copy of the RTEPermissionInfo, if any, corresponding to this RTE
* to the flattened global list.
*/
if (rte->perminfoindex > 0)
{
RTEPermissionInfo *perminfo;
RTEPermissionInfo *newperminfo;
/* Get the existing one from this query's rteperminfos. */
perminfo = getRTEPermissionInfo(rteperminfos, newrte);
/*
* Add a new one to finalrteperminfos and copy the contents of the
* existing one into it. Note that addRTEPermissionInfo() also
* updates newrte->perminfoindex to point to newperminfo in
* finalrteperminfos.
*/
newrte->perminfoindex = 0; /* expected by addRTEPermissionInfo() */
newperminfo = addRTEPermissionInfo(&glob->finalrteperminfos, newrte);
memcpy(newperminfo, perminfo, sizeof(RTEPermissionInfo));
}
}
/*
* set_plan_refs: recurse through the Plan nodes of a single subquery level
*/
static Plan *
set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
{
ListCell *l;
if (plan == NULL)
return NULL;
/* Assign this node a unique ID. */
plan->plan_node_id = root->glob->lastPlanNodeId++;
/*
* Plan-type-specific fixes
*/
switch (nodeTag(plan))
{
case T_SeqScan:
{
SeqScan *splan = (SeqScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_SampleScan:
{
SampleScan *splan = (SampleScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->tablesample = (TableSampleClause *)
fix_scan_expr(root, (Node *) splan->tablesample,
rtoffset, 1);
}
break;
case T_IndexScan:
{
IndexScan *splan = (IndexScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->indexqual =
fix_scan_list(root, splan->indexqual,
rtoffset, 1);
splan->indexqualorig =
fix_scan_list(root, splan->indexqualorig,
rtoffset, NUM_EXEC_QUAL(plan));
splan->indexorderby =
fix_scan_list(root, splan->indexorderby,
rtoffset, 1);
splan->indexorderbyorig =
fix_scan_list(root, splan->indexorderbyorig,
rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_IndexOnlyScan:
{
IndexOnlyScan *splan = (IndexOnlyScan *) plan;
return set_indexonlyscan_references(root, splan, rtoffset);
}
break;
case T_BitmapIndexScan:
{
BitmapIndexScan *splan = (BitmapIndexScan *) plan;
splan->scan.scanrelid += rtoffset;
/* no need to fix targetlist and qual */
Assert(splan->scan.plan.targetlist == NIL);
Assert(splan->scan.plan.qual == NIL);
splan->indexqual =
fix_scan_list(root, splan->indexqual, rtoffset, 1);
splan->indexqualorig =
fix_scan_list(root, splan->indexqualorig,
rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_BitmapHeapScan:
{
BitmapHeapScan *splan = (BitmapHeapScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->bitmapqualorig =
fix_scan_list(root, splan->bitmapqualorig,
rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_TidScan:
{
TidScan *splan = (TidScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->tidquals =
fix_scan_list(root, splan->tidquals,
rtoffset, 1);
}
break;
case T_TidRangeScan:
{
TidRangeScan *splan = (TidRangeScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->tidrangequals =
fix_scan_list(root, splan->tidrangequals,
rtoffset, 1);
}
break;
case T_SubqueryScan:
/* Needs special treatment, see comments below */
return set_subqueryscan_references(root,
(SubqueryScan *) plan,
rtoffset);
case T_FunctionScan:
{
FunctionScan *splan = (FunctionScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->functions =
fix_scan_list(root, splan->functions, rtoffset, 1);
}
break;
case T_TableFuncScan:
{
TableFuncScan *splan = (TableFuncScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->tablefunc = (TableFunc *)
fix_scan_expr(root, (Node *) splan->tablefunc,
rtoffset, 1);
}
break;
case T_ValuesScan:
{
ValuesScan *splan = (ValuesScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
splan->values_lists =
fix_scan_list(root, splan->values_lists,
rtoffset, 1);
}
break;
case T_CteScan:
{
CteScan *splan = (CteScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_NamedTuplestoreScan:
{
NamedTuplestoreScan *splan = (NamedTuplestoreScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_WorkTableScan:
{
WorkTableScan *splan = (WorkTableScan *) plan;
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
fix_scan_list(root, splan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
fix_scan_list(root, splan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_ForeignScan:
set_foreignscan_references(root, (ForeignScan *) plan, rtoffset);
break;
case T_CustomScan:
set_customscan_references(root, (CustomScan *) plan, rtoffset);
break;
case T_NestLoop:
case T_MergeJoin:
case T_HashJoin:
set_join_references(root, (Join *) plan, rtoffset);
break;
case T_Gather:
case T_GatherMerge:
{
set_upper_references(root, plan, rtoffset);
set_param_references(root, plan);
}
break;
case T_Hash:
set_hash_references(root, plan, rtoffset);
break;
case T_Memoize:
{
Memoize *mplan = (Memoize *) plan;
/*
* Memoize does not evaluate its targetlist. It just uses the
* same targetlist from its outer subnode.
*/
set_dummy_tlist_references(plan, rtoffset);
mplan->param_exprs = fix_scan_list(root, mplan->param_exprs,
rtoffset,
NUM_EXEC_TLIST(plan));
break;
}
case T_Material:
case T_Sort:
case T_IncrementalSort:
case T_Unique:
case T_SetOp:
/*
* These plan types don't actually bother to evaluate their
* targetlists, because they just return their unmodified input
* tuples. Even though the targetlist won't be used by the
* executor, we fix it up for possible use by EXPLAIN (not to
* mention ease of debugging --- wrong varnos are very confusing).
*/
set_dummy_tlist_references(plan, rtoffset);
/*
* Since these plan types don't check quals either, we should not
* find any qual expression attached to them.
*/
Assert(plan->qual == NIL);
break;
case T_LockRows:
{
LockRows *splan = (LockRows *) plan;
/*
* Like the plan types above, LockRows doesn't evaluate its
* tlist or quals. But we have to fix up the RT indexes in
* its rowmarks.
*/
set_dummy_tlist_references(plan, rtoffset);
Assert(splan->plan.qual == NIL);
foreach(l, splan->rowMarks)
{
PlanRowMark *rc = (PlanRowMark *) lfirst(l);
rc->rti += rtoffset;
rc->prti += rtoffset;
}
}
break;
case T_Limit:
{
Limit *splan = (Limit *) plan;
/*
* Like the plan types above, Limit doesn't evaluate its tlist
* or quals. It does have live expressions for limit/offset,
* however; and those cannot contain subplan variable refs, so
* fix_scan_expr works for them.
*/
set_dummy_tlist_references(plan, rtoffset);
Assert(splan->plan.qual == NIL);
splan->limitOffset =
fix_scan_expr(root, splan->limitOffset, rtoffset, 1);
splan->limitCount =
fix_scan_expr(root, splan->limitCount, rtoffset, 1);
}
break;
case T_Agg:
{
Agg *agg = (Agg *) plan;
/*
* If this node is combining partial-aggregation results, we
* must convert its Aggrefs to contain references to the
* partial-aggregate subexpressions that will be available
* from the child plan node.
*/
if (DO_AGGSPLIT_COMBINE(agg->aggsplit))
{
plan->targetlist = (List *)
convert_combining_aggrefs((Node *) plan->targetlist,
NULL);
plan->qual = (List *)
convert_combining_aggrefs((Node *) plan->qual,
NULL);
}
set_upper_references(root, plan, rtoffset);
}
break;
case T_Group:
set_upper_references(root, plan, rtoffset);
break;
case T_WindowAgg:
{
WindowAgg *wplan = (WindowAgg *) plan;
/*
* Adjust the WindowAgg's run conditions by swapping the
* WindowFuncs references out to instead reference the Var in
* the scan slot so that when the executor evaluates the
* runCondition, it receives the WindowFunc's value from the
* slot that the result has just been stored into rather than
* evaluating the WindowFunc all over again.
*/
wplan->runCondition = set_windowagg_runcondition_references(root,
wplan->runCondition,
(Plan *) wplan);
set_upper_references(root, plan, rtoffset);
/*
* Like Limit node limit/offset expressions, WindowAgg has
* frame offset expressions, which cannot contain subplan
* variable refs, so fix_scan_expr works for them.
*/
wplan->startOffset =
fix_scan_expr(root, wplan->startOffset, rtoffset, 1);
wplan->endOffset =
fix_scan_expr(root, wplan->endOffset, rtoffset, 1);
wplan->runCondition = fix_scan_list(root,
wplan->runCondition,
rtoffset,
NUM_EXEC_TLIST(plan));
wplan->runConditionOrig = fix_scan_list(root,
wplan->runConditionOrig,
rtoffset,
NUM_EXEC_TLIST(plan));
}
break;
case T_Result:
{
Result *splan = (Result *) plan;
/*
* Result may or may not have a subplan; if not, it's more
* like a scan node than an upper node.
*/
if (splan->plan.lefttree != NULL)
set_upper_references(root, plan, rtoffset);
else
{
/*
* The tlist of a childless Result could contain
* unresolved ROWID_VAR Vars, in case it's representing a
* target relation which is completely empty because of
* constraint exclusion. Replace any such Vars by null
* constants, as though they'd been resolved for a leaf
* scan node that doesn't support them. We could have
* fix_scan_expr do this, but since the case is only
* expected to occur here, it seems safer to special-case
* it here and keep the assertions that ROWID_VARs
* shouldn't be seen by fix_scan_expr.
*/
foreach(l, splan->plan.targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Var *var = (Var *) tle->expr;
if (var && IsA(var, Var) && var->varno == ROWID_VAR)
tle->expr = (Expr *) makeNullConst(var->vartype,
var->vartypmod,
var->varcollid);
}
splan->plan.targetlist =
fix_scan_list(root, splan->plan.targetlist,
rtoffset, NUM_EXEC_TLIST(plan));
splan->plan.qual =
fix_scan_list(root, splan->plan.qual,
rtoffset, NUM_EXEC_QUAL(plan));
}
/* resconstantqual can't contain any subplan variable refs */
splan->resconstantqual =
fix_scan_expr(root, splan->resconstantqual, rtoffset, 1);
}
break;
case T_ProjectSet:
set_upper_references(root, plan, rtoffset);
break;
case T_ModifyTable:
{
ModifyTable *splan = (ModifyTable *) plan;
Plan *subplan = outerPlan(splan);
Assert(splan->plan.targetlist == NIL);
Assert(splan->plan.qual == NIL);
splan->withCheckOptionLists =
fix_scan_list(root, splan->withCheckOptionLists,
rtoffset, 1);
if (splan->returningLists)
{
List *newRL = NIL;
ListCell *lcrl,
*lcrr;
/*
* Pass each per-resultrel returningList through
* set_returning_clause_references().
*/
Assert(list_length(splan->returningLists) == list_length(splan->resultRelations));
forboth(lcrl, splan->returningLists,
lcrr, splan->resultRelations)
{
List *rlist = (List *) lfirst(lcrl);
Index resultrel = lfirst_int(lcrr);
rlist = set_returning_clause_references(root,
rlist,
subplan,
resultrel,
rtoffset);
newRL = lappend(newRL, rlist);
}
splan->returningLists = newRL;
/*
* Set up the visible plan targetlist as being the same as
* the first RETURNING list. This is for the use of
* EXPLAIN; the executor won't pay any attention to the
* targetlist. We postpone this step until here so that
* we don't have to do set_returning_clause_references()
* twice on identical targetlists.
*/
splan->plan.targetlist = copyObject(linitial(newRL));
}
/*
* We treat ModifyTable with ON CONFLICT as a form of 'pseudo
* join', where the inner side is the EXCLUDED tuple.
* Therefore use fix_join_expr to setup the relevant variables
* to INNER_VAR. We explicitly don't create any OUTER_VARs as
* those are already used by RETURNING and it seems better to
* be non-conflicting.
*/
if (splan->onConflictSet)
{
indexed_tlist *itlist;
itlist = build_tlist_index(splan->exclRelTlist);
splan->onConflictSet =
fix_join_expr(root, splan->onConflictSet,
NULL, itlist,
linitial_int(splan->resultRelations),
rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan));
splan->onConflictWhere = (Node *)
fix_join_expr(root, (List *) splan->onConflictWhere,
NULL, itlist,
linitial_int(splan->resultRelations),
rtoffset, NRM_EQUAL, NUM_EXEC_QUAL(plan));
pfree(itlist);
splan->exclRelTlist =
fix_scan_list(root, splan->exclRelTlist, rtoffset, 1);
}
/*
* The MERGE statement produces the target rows by performing
* a right join between the target relation and the source
* relation (which could be a plain relation or a subquery).
* The INSERT and UPDATE actions of the MERGE statement
* require access to the columns from the source relation. We
* arrange things so that the source relation attributes are
* available as INNER_VAR and the target relation attributes
* are available from the scan tuple.
*/
if (splan->mergeActionLists != NIL)
{
ListCell *lca,
*lcr;
/*
* Fix the targetList of individual action nodes so that
* the so-called "source relation" Vars are referenced as
* INNER_VAR. Note that for this to work correctly during
* execution, the ecxt_innertuple must be set to the tuple
* obtained by executing the subplan, which is what
* constitutes the "source relation".
*
* We leave the Vars from the result relation (i.e. the
* target relation) unchanged i.e. those Vars would be
* picked from the scan slot. So during execution, we must
* ensure that ecxt_scantuple is setup correctly to refer
* to the tuple from the target relation.
*/
indexed_tlist *itlist;
itlist = build_tlist_index(subplan->targetlist);
forboth(lca, splan->mergeActionLists,
lcr, splan->resultRelations)
{
List *mergeActionList = lfirst(lca);
Index resultrel = lfirst_int(lcr);
foreach(l, mergeActionList)
{
MergeAction *action = (MergeAction *) lfirst(l);
/* Fix targetList of each action. */
action->targetList = fix_join_expr(root,
action->targetList,
NULL, itlist,
resultrel,
rtoffset,
NRM_EQUAL,
NUM_EXEC_TLIST(plan));
/* Fix quals too. */
action->qual = (Node *) fix_join_expr(root,
(List *) action->qual,
NULL, itlist,
resultrel,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL(plan));
}
}
}
splan->nominalRelation += rtoffset;
if (splan->rootRelation)
splan->rootRelation += rtoffset;
splan->exclRelRTI += rtoffset;
foreach(l, splan->resultRelations)
{
lfirst_int(l) += rtoffset;
}
foreach(l, splan->rowMarks)
{
PlanRowMark *rc = (PlanRowMark *) lfirst(l);
rc->rti += rtoffset;
rc->prti += rtoffset;
}
/*
* Append this ModifyTable node's final result relation RT
* index(es) to the global list for the plan.
*/
root->glob->resultRelations =
list_concat(root->glob->resultRelations,
splan->resultRelations);
if (splan->rootRelation)
{
root->glob->resultRelations =
lappend_int(root->glob->resultRelations,
splan->rootRelation);
}
}
break;
case T_Append:
/* Needs special treatment, see comments below */
return set_append_references(root,
(Append *) plan,
rtoffset);
case T_MergeAppend:
/* Needs special treatment, see comments below */
return set_mergeappend_references(root,
(MergeAppend *) plan,
rtoffset);
case T_RecursiveUnion:
/* This doesn't evaluate targetlist or check quals either */
set_dummy_tlist_references(plan, rtoffset);
Assert(plan->qual == NIL);
break;
case T_BitmapAnd:
{
BitmapAnd *splan = (BitmapAnd *) plan;
/* BitmapAnd works like Append, but has no tlist */
Assert(splan->plan.targetlist == NIL);
Assert(splan->plan.qual == NIL);
foreach(l, splan->bitmapplans)
{
lfirst(l) = set_plan_refs(root,
(Plan *) lfirst(l),
rtoffset);
}
}
break;
case T_BitmapOr:
{
BitmapOr *splan = (BitmapOr *) plan;
/* BitmapOr works like Append, but has no tlist */
Assert(splan->plan.targetlist == NIL);
Assert(splan->plan.qual == NIL);
foreach(l, splan->bitmapplans)
{
lfirst(l) = set_plan_refs(root,
(Plan *) lfirst(l),
rtoffset);
}
}
break;
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(plan));
break;
}
/*
* Now recurse into child plans, if any
*
* NOTE: it is essential that we recurse into child plans AFTER we set
* subplan references in this plan's tlist and quals. If we did the
* reference-adjustments bottom-up, then we would fail to match this
* plan's var nodes against the already-modified nodes of the children.
*/
plan->lefttree = set_plan_refs(root, plan->lefttree, rtoffset);
plan->righttree = set_plan_refs(root, plan->righttree, rtoffset);
return plan;
}
/*
* set_indexonlyscan_references
* Do set_plan_references processing on an IndexOnlyScan
*
* This is unlike the handling of a plain IndexScan because we have to
* convert Vars referencing the heap into Vars referencing the index.
* We can use the fix_upper_expr machinery for that, by working from a
* targetlist describing the index columns.
*/
static Plan *
set_indexonlyscan_references(PlannerInfo *root,
IndexOnlyScan *plan,
int rtoffset)
{
indexed_tlist *index_itlist;
List *stripped_indextlist;
ListCell *lc;
/*
* Vars in the plan node's targetlist, qual, and recheckqual must only
* reference columns that the index AM can actually return. To ensure
* this, remove non-returnable columns (which are marked as resjunk) from
* the indexed tlist. We can just drop them because the indexed_tlist
* machinery pays attention to TLE resnos, not physical list position.
*/
stripped_indextlist = NIL;
foreach(lc, plan->indextlist)
{
TargetEntry *indextle = (TargetEntry *) lfirst(lc);
if (!indextle->resjunk)
stripped_indextlist = lappend(stripped_indextlist, indextle);
}
index_itlist = build_tlist_index(stripped_indextlist);
plan->scan.scanrelid += rtoffset;
plan->scan.plan.targetlist = (List *)
fix_upper_expr(root,
(Node *) plan->scan.plan.targetlist,
index_itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_TLIST((Plan *) plan));
plan->scan.plan.qual = (List *)
fix_upper_expr(root,
(Node *) plan->scan.plan.qual,
index_itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) plan));
plan->recheckqual = (List *)
fix_upper_expr(root,
(Node *) plan->recheckqual,
index_itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) plan));
/* indexqual is already transformed to reference index columns */
plan->indexqual = fix_scan_list(root, plan->indexqual,
rtoffset, 1);
/* indexorderby is already transformed to reference index columns */
plan->indexorderby = fix_scan_list(root, plan->indexorderby,
rtoffset, 1);
/* indextlist must NOT be transformed to reference index columns */
plan->indextlist = fix_scan_list(root, plan->indextlist,
rtoffset, NUM_EXEC_TLIST((Plan *) plan));
pfree(index_itlist);
return (Plan *) plan;
}
/*
* set_subqueryscan_references
* Do set_plan_references processing on a SubqueryScan
*
* We try to strip out the SubqueryScan entirely; if we can't, we have
* to do the normal processing on it.
*/
static Plan *
set_subqueryscan_references(PlannerInfo *root,
SubqueryScan *plan,
int rtoffset)
{
RelOptInfo *rel;
Plan *result;
/* Need to look up the subquery's RelOptInfo, since we need its subroot */
rel = find_base_rel(root, plan->scan.scanrelid);
/* Recursively process the subplan */
plan->subplan = set_plan_references(rel->subroot, plan->subplan);
if (trivial_subqueryscan(plan))
{
/*
* We can omit the SubqueryScan node and just pull up the subplan.
*/
result = clean_up_removed_plan_level((Plan *) plan, plan->subplan);
}
else
{
/*
* Keep the SubqueryScan node. We have to do the processing that
* set_plan_references would otherwise have done on it. Notice we do
* not do set_upper_references() here, because a SubqueryScan will
* always have been created with correct references to its subplan's
* outputs to begin with.
*/
plan->scan.scanrelid += rtoffset;
plan->scan.plan.targetlist =
fix_scan_list(root, plan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST((Plan *) plan));
plan->scan.plan.qual =
fix_scan_list(root, plan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL((Plan *) plan));
result = (Plan *) plan;
}
return result;
}
/*
* trivial_subqueryscan
* Detect whether a SubqueryScan can be deleted from the plan tree.
*
* We can delete it if it has no qual to check and the targetlist just
* regurgitates the output of the child plan.
*
* This can be called from mark_async_capable_plan(), a helper function for
* create_append_plan(), before set_subqueryscan_references(), to determine
* triviality of a SubqueryScan that is a child of an Append node. So we
* cache the result in the SubqueryScan node to avoid repeated computation.
*
* Note: when called from mark_async_capable_plan(), we determine the result
* before running finalize_plan() on the SubqueryScan node (if needed) and
* set_plan_references() on the subplan tree, but this would be safe, because
* 1) finalize_plan() doesn't modify the tlist or quals for the SubqueryScan
* node (or that for any plan node in the subplan tree), and
* 2) set_plan_references() modifies the tlist for every plan node in the
* subplan tree, but keeps const/resjunk columns as const/resjunk ones and
* preserves the length and order of the tlist, and
* 3) set_plan_references() might delete the topmost plan node like an Append
* or MergeAppend from the subplan tree and pull up the child plan node,
* but in that case, the tlist for the child plan node exactly matches the
* parent.
*/
bool
trivial_subqueryscan(SubqueryScan *plan)
{
int attrno;
ListCell *lp,
*lc;
/* We might have detected this already; in which case reuse the result */
if (plan->scanstatus == SUBQUERY_SCAN_TRIVIAL)
return true;
if (plan->scanstatus == SUBQUERY_SCAN_NONTRIVIAL)
return false;
Assert(plan->scanstatus == SUBQUERY_SCAN_UNKNOWN);
/* Initially, mark the SubqueryScan as non-deletable from the plan tree */
plan->scanstatus = SUBQUERY_SCAN_NONTRIVIAL;
if (plan->scan.plan.qual != NIL)
return false;
if (list_length(plan->scan.plan.targetlist) !=
list_length(plan->subplan->targetlist))
return false; /* tlists not same length */
attrno = 1;
forboth(lp, plan->scan.plan.targetlist, lc, plan->subplan->targetlist)
{
TargetEntry *ptle = (TargetEntry *) lfirst(lp);
TargetEntry *ctle = (TargetEntry *) lfirst(lc);
if (ptle->resjunk != ctle->resjunk)
return false; /* tlist doesn't match junk status */
/*
* We accept either a Var referencing the corresponding element of the
* subplan tlist, or a Const equaling the subplan element. See
* generate_setop_tlist() for motivation.
*/
if (ptle->expr && IsA(ptle->expr, Var))
{
Var *var = (Var *) ptle->expr;
Assert(var->varno == plan->scan.scanrelid);
Assert(var->varlevelsup == 0);
if (var->varattno != attrno)
return false; /* out of order */
}
else if (ptle->expr && IsA(ptle->expr, Const))
{
if (!equal(ptle->expr, ctle->expr))
return false;
}
else
return false;
attrno++;
}
/* Re-mark the SubqueryScan as deletable from the plan tree */
plan->scanstatus = SUBQUERY_SCAN_TRIVIAL;
return true;
}
/*
* clean_up_removed_plan_level
* Do necessary cleanup when we strip out a SubqueryScan, Append, etc
*
* We are dropping the "parent" plan in favor of returning just its "child".
* A few small tweaks are needed.
*/
static Plan *
clean_up_removed_plan_level(Plan *parent, Plan *child)
{
/*
* We have to be sure we don't lose any initplans, so move any that were
* attached to the parent plan to the child. If we do move any, the child
* is no longer parallel-safe.
*/
if (parent->initPlan)
child->parallel_safe = false;
/*
* Attach plans this way so that parent's initplans are processed before
* any pre-existing initplans of the child. Probably doesn't matter, but
* let's preserve the ordering just in case.
*/
child->initPlan = list_concat(parent->initPlan,
child->initPlan);
/*
* We also have to transfer the parent's column labeling info into the
* child, else columns sent to client will be improperly labeled if this
* is the topmost plan level. resjunk and so on may be important too.
*/
apply_tlist_labeling(child->targetlist, parent->targetlist);
return child;
}
/*
* set_foreignscan_references
* Do set_plan_references processing on a ForeignScan
*/
static void
set_foreignscan_references(PlannerInfo *root,
ForeignScan *fscan,
int rtoffset)
{
/* Adjust scanrelid if it's valid */
if (fscan->scan.scanrelid > 0)
fscan->scan.scanrelid += rtoffset;
if (fscan->fdw_scan_tlist != NIL || fscan->scan.scanrelid == 0)
{
/*
* Adjust tlist, qual, fdw_exprs, fdw_recheck_quals to reference
* foreign scan tuple
*/
indexed_tlist *itlist = build_tlist_index(fscan->fdw_scan_tlist);
fscan->scan.plan.targetlist = (List *)
fix_upper_expr(root,
(Node *) fscan->scan.plan.targetlist,
itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_TLIST((Plan *) fscan));
fscan->scan.plan.qual = (List *)
fix_upper_expr(root,
(Node *) fscan->scan.plan.qual,
itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_exprs = (List *)
fix_upper_expr(root,
(Node *) fscan->fdw_exprs,
itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_recheck_quals = (List *)
fix_upper_expr(root,
(Node *) fscan->fdw_recheck_quals,
itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) fscan));
pfree(itlist);
/* fdw_scan_tlist itself just needs fix_scan_list() adjustments */
fscan->fdw_scan_tlist =
fix_scan_list(root, fscan->fdw_scan_tlist,
rtoffset, NUM_EXEC_TLIST((Plan *) fscan));
}
else
{
/*
* Adjust tlist, qual, fdw_exprs, fdw_recheck_quals in the standard
* way
*/
fscan->scan.plan.targetlist =
fix_scan_list(root, fscan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST((Plan *) fscan));
fscan->scan.plan.qual =
fix_scan_list(root, fscan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_exprs =
fix_scan_list(root, fscan->fdw_exprs,
rtoffset, NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_recheck_quals =
fix_scan_list(root, fscan->fdw_recheck_quals,
rtoffset, NUM_EXEC_QUAL((Plan *) fscan));
}
fscan->fs_relids = offset_relid_set(fscan->fs_relids, rtoffset);
fscan->fs_base_relids = offset_relid_set(fscan->fs_base_relids, rtoffset);
/* Adjust resultRelation if it's valid */
if (fscan->resultRelation > 0)
fscan->resultRelation += rtoffset;
}
/*
* set_customscan_references
* Do set_plan_references processing on a CustomScan
*/
static void
set_customscan_references(PlannerInfo *root,
CustomScan *cscan,
int rtoffset)
{
ListCell *lc;
/* Adjust scanrelid if it's valid */
if (cscan->scan.scanrelid > 0)
cscan->scan.scanrelid += rtoffset;
if (cscan->custom_scan_tlist != NIL || cscan->scan.scanrelid == 0)
{
/* Adjust tlist, qual, custom_exprs to reference custom scan tuple */
indexed_tlist *itlist = build_tlist_index(cscan->custom_scan_tlist);
cscan->scan.plan.targetlist = (List *)
fix_upper_expr(root,
(Node *) cscan->scan.plan.targetlist,
itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_TLIST((Plan *) cscan));
cscan->scan.plan.qual = (List *)
fix_upper_expr(root,
(Node *) cscan->scan.plan.qual,
itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) cscan));
cscan->custom_exprs = (List *)
fix_upper_expr(root,
(Node *) cscan->custom_exprs,
itlist,
INDEX_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) cscan));
pfree(itlist);
/* custom_scan_tlist itself just needs fix_scan_list() adjustments */
cscan->custom_scan_tlist =
fix_scan_list(root, cscan->custom_scan_tlist,
rtoffset, NUM_EXEC_TLIST((Plan *) cscan));
}
else
{
/* Adjust tlist, qual, custom_exprs in the standard way */
cscan->scan.plan.targetlist =
fix_scan_list(root, cscan->scan.plan.targetlist,
rtoffset, NUM_EXEC_TLIST((Plan *) cscan));
cscan->scan.plan.qual =
fix_scan_list(root, cscan->scan.plan.qual,
rtoffset, NUM_EXEC_QUAL((Plan *) cscan));
cscan->custom_exprs =
fix_scan_list(root, cscan->custom_exprs,
rtoffset, NUM_EXEC_QUAL((Plan *) cscan));
}
/* Adjust child plan-nodes recursively, if needed */
foreach(lc, cscan->custom_plans)
{
lfirst(lc) = set_plan_refs(root, (Plan *) lfirst(lc), rtoffset);
}
cscan->custom_relids = offset_relid_set(cscan->custom_relids, rtoffset);
}
/*
* set_append_references
* Do set_plan_references processing on an Append
*
* We try to strip out the Append entirely; if we can't, we have
* to do the normal processing on it.
*/
static Plan *
set_append_references(PlannerInfo *root,
Append *aplan,
int rtoffset)
{
ListCell *l;
/*
* Append, like Sort et al, doesn't actually evaluate its targetlist or
* check quals. If it's got exactly one child plan, then it's not doing
* anything useful at all, and we can strip it out.
*/
Assert(aplan->plan.qual == NIL);
/* First, we gotta recurse on the children */
foreach(l, aplan->appendplans)
{
lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset);
}
/*
* See if it's safe to get rid of the Append entirely. For this to be
* safe, there must be only one child plan and that child plan's parallel
* awareness must match the Append's. The reason for the latter is that
* if the Append is parallel aware and the child is not, then the calling
* plan may execute the non-parallel aware child multiple times. (If you
* change these rules, update create_append_path to match.)
*/
if (list_length(aplan->appendplans) == 1)
{
Plan *p = (Plan *) linitial(aplan->appendplans);
if (p->parallel_aware == aplan->plan.parallel_aware)
return clean_up_removed_plan_level((Plan *) aplan, p);
}
/*
* Otherwise, clean up the Append as needed. It's okay to do this after
* recursing to the children, because set_dummy_tlist_references doesn't
* look at those.
*/
set_dummy_tlist_references((Plan *) aplan, rtoffset);
aplan->apprelids = offset_relid_set(aplan->apprelids, rtoffset);
if (aplan->part_prune_info)
{
foreach(l, aplan->part_prune_info->prune_infos)
{
List *prune_infos = lfirst(l);
ListCell *l2;
foreach(l2, prune_infos)
{
PartitionedRelPruneInfo *pinfo = lfirst(l2);
pinfo->rtindex += rtoffset;
}
}
}
/* We don't need to recurse to lefttree or righttree ... */
Assert(aplan->plan.lefttree == NULL);
Assert(aplan->plan.righttree == NULL);
return (Plan *) aplan;
}
/*
* set_mergeappend_references
* Do set_plan_references processing on a MergeAppend
*
* We try to strip out the MergeAppend entirely; if we can't, we have
* to do the normal processing on it.
*/
static Plan *
set_mergeappend_references(PlannerInfo *root,
MergeAppend *mplan,
int rtoffset)
{
ListCell *l;
/*
* MergeAppend, like Sort et al, doesn't actually evaluate its targetlist
* or check quals. If it's got exactly one child plan, then it's not
* doing anything useful at all, and we can strip it out.
*/
Assert(mplan->plan.qual == NIL);
/* First, we gotta recurse on the children */
foreach(l, mplan->mergeplans)
{
lfirst(l) = set_plan_refs(root, (Plan *) lfirst(l), rtoffset);
}
/*
* See if it's safe to get rid of the MergeAppend entirely. For this to
* be safe, there must be only one child plan and that child plan's
* parallel awareness must match the MergeAppend's. The reason for the
* latter is that if the MergeAppend is parallel aware and the child is
* not, then the calling plan may execute the non-parallel aware child
* multiple times. (If you change these rules, update
* create_merge_append_path to match.)
*/
if (list_length(mplan->mergeplans) == 1)
{
Plan *p = (Plan *) linitial(mplan->mergeplans);
if (p->parallel_aware == mplan->plan.parallel_aware)
return clean_up_removed_plan_level((Plan *) mplan, p);
}
/*
* Otherwise, clean up the MergeAppend as needed. It's okay to do this
* after recursing to the children, because set_dummy_tlist_references
* doesn't look at those.
*/
set_dummy_tlist_references((Plan *) mplan, rtoffset);
mplan->apprelids = offset_relid_set(mplan->apprelids, rtoffset);
if (mplan->part_prune_info)
{
foreach(l, mplan->part_prune_info->prune_infos)
{
List *prune_infos = lfirst(l);
ListCell *l2;
foreach(l2, prune_infos)
{
PartitionedRelPruneInfo *pinfo = lfirst(l2);
pinfo->rtindex += rtoffset;
}
}
}
/* We don't need to recurse to lefttree or righttree ... */
Assert(mplan->plan.lefttree == NULL);
Assert(mplan->plan.righttree == NULL);
return (Plan *) mplan;
}
/*
* set_hash_references
* Do set_plan_references processing on a Hash node
*/
static void
set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset)
{
Hash *hplan = (Hash *) plan;
Plan *outer_plan = plan->lefttree;
indexed_tlist *outer_itlist;
/*
* Hash's hashkeys are used when feeding tuples into the hashtable,
* therefore have them reference Hash's outer plan (which itself is the
* inner plan of the HashJoin).
*/
outer_itlist = build_tlist_index(outer_plan->targetlist);
hplan->hashkeys = (List *)
fix_upper_expr(root,
(Node *) hplan->hashkeys,
outer_itlist,
OUTER_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL(plan));
/* Hash doesn't project */
set_dummy_tlist_references(plan, rtoffset);
/* Hash nodes don't have their own quals */
Assert(plan->qual == NIL);
}
/*
* offset_relid_set
* Apply rtoffset to the members of a Relids set.
*/
static Relids
offset_relid_set(Relids relids, int rtoffset)
{
Relids result = NULL;
int rtindex;
/* If there's no offset to apply, we needn't recompute the value */
if (rtoffset == 0)
return relids;
rtindex = -1;
while ((rtindex = bms_next_member(relids, rtindex)) >= 0)
result = bms_add_member(result, rtindex + rtoffset);
return result;
}
/*
* copyVar
* Copy a Var node.
*
* fix_scan_expr and friends do this enough times that it's worth having
* a bespoke routine instead of using the generic copyObject() function.
*/
static inline Var *
copyVar(Var *var)
{
Var *newvar = (Var *) palloc(sizeof(Var));
*newvar = *var;
return newvar;
}
/*
* fix_expr_common
* Do generic set_plan_references processing on an expression node
*
* This is code that is common to all variants of expression-fixing.
* We must look up operator opcode info for OpExpr and related nodes,
* add OIDs from regclass Const nodes into root->glob->relationOids, and
* add PlanInvalItems for user-defined functions into root->glob->invalItems.
* We also fill in column index lists for GROUPING() expressions.
*
* We assume it's okay to update opcode info in-place. So this could possibly
* scribble on the planner's input data structures, but it's OK.
*/
static void
fix_expr_common(PlannerInfo *root, Node *node)
{
/* We assume callers won't call us on a NULL pointer */
if (IsA(node, Aggref))
{
record_plan_function_dependency(root,
((Aggref *) node)->aggfnoid);
}
else if (IsA(node, WindowFunc))
{
record_plan_function_dependency(root,
((WindowFunc *) node)->winfnoid);
}
else if (IsA(node, FuncExpr))
{
record_plan_function_dependency(root,
((FuncExpr *) node)->funcid);
}
else if (IsA(node, OpExpr))
{
set_opfuncid((OpExpr *) node);
record_plan_function_dependency(root,
((OpExpr *) node)->opfuncid);
}
else if (IsA(node, DistinctExpr))
{
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
record_plan_function_dependency(root,
((DistinctExpr *) node)->opfuncid);
}
else if (IsA(node, NullIfExpr))
{
set_opfuncid((OpExpr *) node); /* rely on struct equivalence */
record_plan_function_dependency(root,
((NullIfExpr *) node)->opfuncid);
}
else if (IsA(node, ScalarArrayOpExpr))
{
ScalarArrayOpExpr *saop = (ScalarArrayOpExpr *) node;
set_sa_opfuncid(saop);
record_plan_function_dependency(root, saop->opfuncid);
if (!OidIsValid(saop->hashfuncid))
record_plan_function_dependency(root, saop->hashfuncid);
if (!OidIsValid(saop->negfuncid))
record_plan_function_dependency(root, saop->negfuncid);
}
else if (IsA(node, Const))
{
Const *con = (Const *) node;
/* Check for regclass reference */
if (ISREGCLASSCONST(con))
root->glob->relationOids =
lappend_oid(root->glob->relationOids,
DatumGetObjectId(con->constvalue));
}
else if (IsA(node, GroupingFunc))
{
GroupingFunc *g = (GroupingFunc *) node;
AttrNumber *grouping_map = root->grouping_map;
/* If there are no grouping sets, we don't need this. */
Assert(grouping_map || g->cols == NIL);
if (grouping_map)
{
ListCell *lc;
List *cols = NIL;
foreach(lc, g->refs)
{
cols = lappend_int(cols, grouping_map[lfirst_int(lc)]);
}
Assert(!g->cols || equal(cols, g->cols));
if (!g->cols)
g->cols = cols;
}
}
}
/*
* fix_param_node
* Do set_plan_references processing on a Param
*
* If it's a PARAM_MULTIEXPR, replace it with the appropriate Param from
* root->multiexpr_params; otherwise no change is needed.
* Just for paranoia's sake, we make a copy of the node in either case.
*/
static Node *
fix_param_node(PlannerInfo *root, Param *p)
{
if (p->paramkind == PARAM_MULTIEXPR)
{
int subqueryid = p->paramid >> 16;
int colno = p->paramid & 0xFFFF;
List *params;
if (subqueryid <= 0 ||
subqueryid > list_length(root->multiexpr_params))
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
params = (List *) list_nth(root->multiexpr_params, subqueryid - 1);
if (colno <= 0 || colno > list_length(params))
elog(ERROR, "unexpected PARAM_MULTIEXPR ID: %d", p->paramid);
return copyObject(list_nth(params, colno - 1));
}
return (Node *) copyObject(p);
}
/*
* fix_alternative_subplan
* Do set_plan_references processing on an AlternativeSubPlan
*
* Choose one of the alternative implementations and return just that one,
* discarding the rest of the AlternativeSubPlan structure.
* Note: caller must still recurse into the result!
*
* We don't make any attempt to fix up cost estimates in the parent plan
* node or higher-level nodes.
*/
static Node *
fix_alternative_subplan(PlannerInfo *root, AlternativeSubPlan *asplan,
double num_exec)
{
SubPlan *bestplan = NULL;
Cost bestcost = 0;
ListCell *lc;
/*
* Compute the estimated cost of each subplan assuming num_exec
* executions, and keep the cheapest one. In event of exact equality of
* estimates, we prefer the later plan; this is a bit arbitrary, but in
* current usage it biases us to break ties against fast-start subplans.
*/
Assert(asplan->subplans != NIL);
foreach(lc, asplan->subplans)
{
SubPlan *curplan = (SubPlan *) lfirst(lc);
Cost curcost;
curcost = curplan->startup_cost + num_exec * curplan->per_call_cost;
if (bestplan == NULL || curcost <= bestcost)
{
bestplan = curplan;
bestcost = curcost;
}
/* Also mark all subplans that are in AlternativeSubPlans */
root->isAltSubplan[curplan->plan_id - 1] = true;
}
/* Mark the subplan we selected */
root->isUsedSubplan[bestplan->plan_id - 1] = true;
return (Node *) bestplan;
}
/*
* fix_scan_expr
* Do set_plan_references processing on a scan-level expression
*
* This consists of incrementing all Vars' varnos by rtoffset,
* replacing PARAM_MULTIEXPR Params, expanding PlaceHolderVars,
* replacing Aggref nodes that should be replaced by initplan output Params,
* choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
* and adding OIDs from regclass Const nodes into root->glob->relationOids.
*
* 'node': the expression to be modified
* 'rtoffset': how much to increment varnos by
* 'num_exec': estimated number of executions of expression
*
* The expression tree is either copied-and-modified, or modified in-place
* if that seems safe.
*/
static Node *
fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
{
fix_scan_expr_context context;
context.root = root;
context.rtoffset = rtoffset;
context.num_exec = num_exec;
if (rtoffset != 0 ||
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
root->minmax_aggs != NIL ||
root->hasAlternativeSubPlans)
{
return fix_scan_expr_mutator(node, &context);
}
else
{
/*
* If rtoffset == 0, we don't need to change any Vars, and if there
* are no MULTIEXPR subqueries then we don't need to replace
* PARAM_MULTIEXPR Params, and if there are no placeholders anywhere
* we won't need to remove them, and if there are no minmax Aggrefs we
* won't need to replace them, and if there are no AlternativeSubPlans
* we won't need to remove them. Then it's OK to just scribble on the
* input node tree instead of copying (since the only change, filling
* in any unset opfuncid fields, is harmless). This saves just enough
* cycles to be noticeable on trivial queries.
*/
(void) fix_scan_expr_walker(node, &context);
return node;
}
}
static Node *
fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context)
{
if (node == NULL)
return NULL;
if (IsA(node, Var))
{
Var *var = copyVar((Var *) node);
Assert(var->varlevelsup == 0);
/*
* We should not see Vars marked INNER_VAR, OUTER_VAR, or ROWID_VAR.
* But an indexqual expression could contain INDEX_VAR Vars.
*/
Assert(var->varno != INNER_VAR);
Assert(var->varno != OUTER_VAR);
Assert(var->varno != ROWID_VAR);
if (!IS_SPECIAL_VARNO(var->varno))
var->varno += context->rtoffset;
if (var->varnosyn > 0)
var->varnosyn += context->rtoffset;
return (Node *) var;
}
if (IsA(node, Param))
return fix_param_node(context->root, (Param *) node);
if (IsA(node, Aggref))
{
Aggref *aggref = (Aggref *) node;
/* See if the Aggref should be replaced by a Param */
if (context->root->minmax_aggs != NIL &&
list_length(aggref->args) == 1)
{
TargetEntry *curTarget = (TargetEntry *) linitial(aggref->args);
ListCell *lc;
foreach(lc, context->root->minmax_aggs)
{
MinMaxAggInfo *mminfo = (MinMaxAggInfo *) lfirst(lc);
if (mminfo->aggfnoid == aggref->aggfnoid &&
equal(mminfo->target, curTarget->expr))
return (Node *) copyObject(mminfo->param);
}
}
/* If no match, just fall through to process it normally */
}
if (IsA(node, CurrentOfExpr))
{
CurrentOfExpr *cexpr = (CurrentOfExpr *) copyObject(node);
Assert(!IS_SPECIAL_VARNO(cexpr->cvarno));
cexpr->cvarno += context->rtoffset;
return (Node *) cexpr;
}
if (IsA(node, PlaceHolderVar))
{
/* At scan level, we should always just evaluate the contained expr */
PlaceHolderVar *phv = (PlaceHolderVar *) node;
/* XXX can we assert something about phnullingrels? */
return fix_scan_expr_mutator((Node *) phv->phexpr, context);
}
if (IsA(node, AlternativeSubPlan))
return fix_scan_expr_mutator(fix_alternative_subplan(context->root,
(AlternativeSubPlan *) node,
context->num_exec),
context);
fix_expr_common(context->root, node);
return expression_tree_mutator(node, fix_scan_expr_mutator,
(void *) context);
}
static bool
fix_scan_expr_walker(Node *node, fix_scan_expr_context *context)
{
if (node == NULL)
return false;
Assert(!(IsA(node, Var) && ((Var *) node)->varno == ROWID_VAR));
Assert(!IsA(node, PlaceHolderVar));
Assert(!IsA(node, AlternativeSubPlan));
fix_expr_common(context->root, node);
return expression_tree_walker(node, fix_scan_expr_walker,
(void *) context);
}
/*
* set_join_references
* Modify the target list and quals of a join node to reference its
* subplans, by setting the varnos to OUTER_VAR or INNER_VAR and setting
* attno values to the result domain number of either the corresponding
* outer or inner join tuple item. Also perform opcode lookup for these
* expressions, and add regclass OIDs to root->glob->relationOids.
*/
static void
set_join_references(PlannerInfo *root, Join *join, int rtoffset)
{
Plan *outer_plan = join->plan.lefttree;
Plan *inner_plan = join->plan.righttree;
indexed_tlist *outer_itlist;
indexed_tlist *inner_itlist;
outer_itlist = build_tlist_index(outer_plan->targetlist);
inner_itlist = build_tlist_index(inner_plan->targetlist);
/*
* First process the joinquals (including merge or hash clauses). These
* are logically below the join so they can always use all values
* available from the input tlists. It's okay to also handle
* NestLoopParams now, because those couldn't refer to nullable
* subexpressions.
*/
join->joinqual = fix_join_expr(root,
join->joinqual,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) join));
/* Now do join-type-specific stuff */
if (IsA(join, NestLoop))
{
NestLoop *nl = (NestLoop *) join;
ListCell *lc;
foreach(lc, nl->nestParams)
{
NestLoopParam *nlp = (NestLoopParam *) lfirst(lc);
/*
* Because we don't reparameterize parameterized paths to match
* the outer-join level at which they are used, Vars seen in the
* NestLoopParam expression may have nullingrels that are just a
* subset of those in the Vars actually available from the outer
* side. Not checking this exactly is a bit grotty, but the work
* needed to make things match up perfectly seems well out of
* proportion to the value.
*/
nlp->paramval = (Var *) fix_upper_expr(root,
(Node *) nlp->paramval,
outer_itlist,
OUTER_VAR,
rtoffset,
NRM_SUBSET,
NUM_EXEC_TLIST(outer_plan));
/* Check we replaced any PlaceHolderVar with simple Var */
if (!(IsA(nlp->paramval, Var) &&
nlp->paramval->varno == OUTER_VAR))
elog(ERROR, "NestLoopParam was not reduced to a simple Var");
}
}
else if (IsA(join, MergeJoin))
{
MergeJoin *mj = (MergeJoin *) join;
mj->mergeclauses = fix_join_expr(root,
mj->mergeclauses,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) join));
}
else if (IsA(join, HashJoin))
{
HashJoin *hj = (HashJoin *) join;
hj->hashclauses = fix_join_expr(root,
hj->hashclauses,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) join));
/*
* HashJoin's hashkeys are used to look for matching tuples from its
* outer plan (not the Hash node!) in the hashtable.
*/
hj->hashkeys = (List *) fix_upper_expr(root,
(Node *) hj->hashkeys,
outer_itlist,
OUTER_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL((Plan *) join));
}
/*
* Now we need to fix up the targetlist and qpqual, which are logically
* above the join. This means that, if it's not an inner join, any Vars
* and PHVs appearing here should have nullingrels that include the
* effects of the outer join, ie they will have nullingrels equal to the
* input Vars' nullingrels plus the bit added by the outer join. We don't
* currently have enough info available here to identify what that should
* be, so we just tell fix_join_expr to accept superset nullingrels
* matches instead of exact ones.
*/
join->plan.targetlist = fix_join_expr(root,
join->plan.targetlist,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset,
(join->jointype == JOIN_INNER ? NRM_EQUAL : NRM_SUPERSET),
NUM_EXEC_TLIST((Plan *) join));
join->plan.qual = fix_join_expr(root,
join->plan.qual,
outer_itlist,
inner_itlist,
(Index) 0,
rtoffset,
(join->jointype == JOIN_INNER ? NRM_EQUAL : NRM_SUPERSET),
NUM_EXEC_QUAL((Plan *) join));
pfree(outer_itlist);
pfree(inner_itlist);
}
/*
* set_upper_references
* Update the targetlist and quals of an upper-level plan node
* to refer to the tuples returned by its lefttree subplan.
* Also perform opcode lookup for these expressions, and
* add regclass OIDs to root->glob->relationOids.
*
* This is used for single-input plan types like Agg, Group, Result.
*
* In most cases, we have to match up individual Vars in the tlist and
* qual expressions with elements of the subplan's tlist (which was
* generated by flattening these selfsame expressions, so it should have all
* the required variables). There is an important exception, however:
* depending on where we are in the plan tree, sort/group columns may have
* been pushed into the subplan tlist unflattened. If these values are also
* needed in the output then we want to reference the subplan tlist element
* rather than recomputing the expression.
*/
static void
set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset)
{
Plan *subplan = plan->lefttree;
indexed_tlist *subplan_itlist;
List *output_targetlist;
ListCell *l;
subplan_itlist = build_tlist_index(subplan->targetlist);
output_targetlist = NIL;
foreach(l, plan->targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Node *newexpr;
/* If it's a sort/group item, first try to match by sortref */
if (tle->ressortgroupref != 0)
{
newexpr = (Node *)
search_indexed_tlist_for_sortgroupref(tle->expr,
tle->ressortgroupref,
subplan_itlist,
OUTER_VAR);
if (!newexpr)
newexpr = fix_upper_expr(root,
(Node *) tle->expr,
subplan_itlist,
OUTER_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_TLIST(plan));
}
else
newexpr = fix_upper_expr(root,
(Node *) tle->expr,
subplan_itlist,
OUTER_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_TLIST(plan));
tle = flatCopyTargetEntry(tle);
tle->expr = (Expr *) newexpr;
output_targetlist = lappend(output_targetlist, tle);
}
plan->targetlist = output_targetlist;
plan->qual = (List *)
fix_upper_expr(root,
(Node *) plan->qual,
subplan_itlist,
OUTER_VAR,
rtoffset,
NRM_EQUAL,
NUM_EXEC_QUAL(plan));
pfree(subplan_itlist);
}
/*
* set_param_references
* Initialize the initParam list in Gather or Gather merge node such that
* it contains reference of all the params that needs to be evaluated
* before execution of the node. It contains the initplan params that are
* being passed to the plan nodes below it.
*/
static void
set_param_references(PlannerInfo *root, Plan *plan)
{
Assert(IsA(plan, Gather) || IsA(plan, GatherMerge));
if (plan->lefttree->extParam)
{
PlannerInfo *proot;
Bitmapset *initSetParam = NULL;
ListCell *l;
for (proot = root; proot != NULL; proot = proot->parent_root)
{
foreach(l, proot->init_plans)
{
SubPlan *initsubplan = (SubPlan *) lfirst(l);
ListCell *l2;
foreach(l2, initsubplan->setParam)
{
initSetParam = bms_add_member(initSetParam, lfirst_int(l2));
}
}
}
/*
* Remember the list of all external initplan params that are used by
* the children of Gather or Gather merge node.
*/
if (IsA(plan, Gather))
((Gather *) plan)->initParam =
bms_intersect(plan->lefttree->extParam, initSetParam);
else
((GatherMerge *) plan)->initParam =
bms_intersect(plan->lefttree->extParam, initSetParam);
}
}
/*
* Recursively scan an expression tree and convert Aggrefs to the proper
* intermediate form for combining aggregates. This means (1) replacing each
* one's argument list with a single argument that is the original Aggref
* modified to show partial aggregation and (2) changing the upper Aggref to
* show combining aggregation.
*
* After this step, set_upper_references will replace the partial Aggrefs
* with Vars referencing the lower Agg plan node's outputs, so that the final
* form seen by the executor is a combining Aggref with a Var as input.
*
* It's rather messy to postpone this step until setrefs.c; ideally it'd be
* done in createplan.c. The difficulty is that once we modify the Aggref
* expressions, they will no longer be equal() to their original form and
* so cross-plan-node-level matches will fail. So this has to happen after
* the plan node above the Agg has resolved its subplan references.
*/
static Node *
convert_combining_aggrefs(Node *node, void *context)
{
if (node == NULL)
return NULL;
if (IsA(node, Aggref))
{
Aggref *orig_agg = (Aggref *) node;
Aggref *child_agg;
Aggref *parent_agg;
/* Assert we've not chosen to partial-ize any unsupported cases */
Assert(orig_agg->aggorder == NIL);
Assert(orig_agg->aggdistinct == NIL);
/*
* Since aggregate calls can't be nested, we needn't recurse into the
* arguments. But for safety, flat-copy the Aggref node itself rather
* than modifying it in-place.
*/
child_agg = makeNode(Aggref);
memcpy(child_agg, orig_agg, sizeof(Aggref));
/*
* For the parent Aggref, we want to copy all the fields of the
* original aggregate *except* the args list, which we'll replace
* below, and the aggfilter expression, which should be applied only
* by the child not the parent. Rather than explicitly knowing about
* all the other fields here, we can momentarily modify child_agg to
* provide a suitable source for copyObject.
*/
child_agg->args = NIL;
child_agg->aggfilter = NULL;
parent_agg = copyObject(child_agg);
child_agg->args = orig_agg->args;
child_agg->aggfilter = orig_agg->aggfilter;
/*
* Now, set up child_agg to represent the first phase of partial
* aggregation. For now, assume serialization is required.
*/
mark_partial_aggref(child_agg, AGGSPLIT_INITIAL_SERIAL);
/*
* And set up parent_agg to represent the second phase.
*/
parent_agg->args = list_make1(makeTargetEntry((Expr *) child_agg,
1, NULL, false));
mark_partial_aggref(parent_agg, AGGSPLIT_FINAL_DESERIAL);
return (Node *) parent_agg;
}
return expression_tree_mutator(node, convert_combining_aggrefs,
(void *) context);
}
/*
* set_dummy_tlist_references
* Replace the targetlist of an upper-level plan node with a simple
* list of OUTER_VAR references to its child.
*
* This is used for plan types like Sort and Append that don't evaluate
* their targetlists. Although the executor doesn't care at all what's in
* the tlist, EXPLAIN needs it to be realistic.
*
* Note: we could almost use set_upper_references() here, but it fails for
* Append for lack of a lefttree subplan. Single-purpose code is faster
* anyway.
*/
static void
set_dummy_tlist_references(Plan *plan, int rtoffset)
{
List *output_targetlist;
ListCell *l;
output_targetlist = NIL;
foreach(l, plan->targetlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
Var *oldvar = (Var *) tle->expr;
Var *newvar;
/*
* As in search_indexed_tlist_for_non_var(), we prefer to keep Consts
* as Consts, not Vars referencing Consts. Here, there's no speed
* advantage to be had, but it makes EXPLAIN output look cleaner, and
* again it avoids confusing the executor.
*/
if (IsA(oldvar, Const))
{
/* just reuse the existing TLE node */
output_targetlist = lappend(output_targetlist, tle);
continue;
}
newvar = makeVar(OUTER_VAR,
tle->resno,
exprType((Node *) oldvar),
exprTypmod((Node *) oldvar),
exprCollation((Node *) oldvar),
0);
if (IsA(oldvar, Var) &&
oldvar->varnosyn > 0)
{
newvar->varnosyn = oldvar->varnosyn + rtoffset;
newvar->varattnosyn = oldvar->varattnosyn;
}
else
{
newvar->varnosyn = 0; /* wasn't ever a plain Var */
newvar->varattnosyn = 0;
}
tle = flatCopyTargetEntry(tle);
tle->expr = (Expr *) newvar;
output_targetlist = lappend(output_targetlist, tle);
}
plan->targetlist = output_targetlist;
/* We don't touch plan->qual here */
}
/*
* build_tlist_index --- build an index data structure for a child tlist
*
* In most cases, subplan tlists will be "flat" tlists with only Vars,
* so we try to optimize that case by extracting information about Vars
* in advance. Matching a parent tlist to a child is still an O(N^2)
* operation, but at least with a much smaller constant factor than plain
* tlist_member() searches.
*
* The result of this function is an indexed_tlist struct to pass to
* search_indexed_tlist_for_var() and siblings.
* When done, the indexed_tlist may be freed with a single pfree().
*/
static indexed_tlist *
build_tlist_index(List *tlist)
{
indexed_tlist *itlist;
tlist_vinfo *vinfo;
ListCell *l;
/* Create data structure with enough slots for all tlist entries */
itlist = (indexed_tlist *)
palloc(offsetof(indexed_tlist, vars) +
list_length(tlist) * sizeof(tlist_vinfo));
itlist->tlist = tlist;
itlist->has_ph_vars = false;
itlist->has_non_vars = false;
/* Find the Vars and fill in the index array */
vinfo = itlist->vars;
foreach(l, tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (tle->expr && IsA(tle->expr, Var))
{
Var *var = (Var *) tle->expr;
vinfo->varno = var->varno;
vinfo->varattno = var->varattno;
vinfo->resno = tle->resno;
vinfo->varnullingrels = var->varnullingrels;
vinfo++;
}
else if (tle->expr && IsA(tle->expr, PlaceHolderVar))
itlist->has_ph_vars = true;
else
itlist->has_non_vars = true;
}
itlist->num_vars = (vinfo - itlist->vars);
return itlist;
}
/*
* build_tlist_index_other_vars --- build a restricted tlist index
*
* This is like build_tlist_index, but we only index tlist entries that
* are Vars belonging to some rel other than the one specified. We will set
* has_ph_vars (allowing PlaceHolderVars to be matched), but not has_non_vars
* (so nothing other than Vars and PlaceHolderVars can be matched).
*/
static indexed_tlist *
build_tlist_index_other_vars(List *tlist, int ignore_rel)
{
indexed_tlist *itlist;
tlist_vinfo *vinfo;
ListCell *l;
/* Create data structure with enough slots for all tlist entries */
itlist = (indexed_tlist *)
palloc(offsetof(indexed_tlist, vars) +
list_length(tlist) * sizeof(tlist_vinfo));
itlist->tlist = tlist;
itlist->has_ph_vars = false;
itlist->has_non_vars = false;
/* Find the desired Vars and fill in the index array */
vinfo = itlist->vars;
foreach(l, tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(l);
if (tle->expr && IsA(tle->expr, Var))
{
Var *var = (Var *) tle->expr;
if (var->varno != ignore_rel)
{
vinfo->varno = var->varno;
vinfo->varattno = var->varattno;
vinfo->resno = tle->resno;
vinfo->varnullingrels = var->varnullingrels;
vinfo++;
}
}
else if (tle->expr && IsA(tle->expr, PlaceHolderVar))
itlist->has_ph_vars = true;
}
itlist->num_vars = (vinfo - itlist->vars);
return itlist;
}
/*
* search_indexed_tlist_for_var --- find a Var in an indexed tlist
*
* If a match is found, return a copy of the given Var with suitably
* modified varno/varattno (to wit, newvarno and the resno of the TLE entry).
* Also ensure that varnosyn is incremented by rtoffset.
* If no match, return NULL.
*
* In debugging builds, we cross-check the varnullingrels of the subplan
* output Var based on nrm_match. Most call sites should pass NRM_EQUAL
* indicating we expect an exact match. However, there are places where
* we haven't cleaned things up completely, and we have to settle for
* allowing subset or superset matches.
*/
static Var *
search_indexed_tlist_for_var(Var *var, indexed_tlist *itlist,
int newvarno, int rtoffset,
NullingRelsMatch nrm_match)
{
int varno = var->varno;
AttrNumber varattno = var->varattno;
tlist_vinfo *vinfo;
int i;
vinfo = itlist->vars;
i = itlist->num_vars;
while (i-- > 0)
{
if (vinfo->varno == varno && vinfo->varattno == varattno)
{
/* Found a match */
Var *newvar = copyVar(var);
/*
* Verify that we kept all the nullingrels machinations straight.
*
* XXX we skip the check for system columns and whole-row Vars.
* That's because such Vars might be row identity Vars, which are
* generated without any varnullingrels. It'd be hard to do
* otherwise, since they're normally made very early in planning,
* when we haven't looked at the jointree yet and don't know which
* joins might null such Vars. Doesn't seem worth the expense to
* make them fully valid. (While it's slightly annoying that we
* thereby lose checking for user-written references to such
* columns, it seems unlikely that a bug in nullingrels logic
* would affect only system columns.)
*/
if (!(varattno <= 0 ||
(nrm_match == NRM_SUBSET ?
bms_is_subset(var->varnullingrels, vinfo->varnullingrels) :
nrm_match == NRM_SUPERSET ?
bms_is_subset(vinfo->varnullingrels, var->varnullingrels) :
bms_equal(vinfo->varnullingrels, var->varnullingrels))))
elog(ERROR, "wrong varnullingrels %s (expected %s) for Var %d/%d",
bmsToString(var->varnullingrels),
bmsToString(vinfo->varnullingrels),
varno, varattno);
newvar->varno = newvarno;
newvar->varattno = vinfo->resno;
if (newvar->varnosyn > 0)
newvar->varnosyn += rtoffset;
return newvar;
}
vinfo++;
}
return NULL; /* no match */
}
/*
* search_indexed_tlist_for_phv --- find a PlaceHolderVar in an indexed tlist
*
* If a match is found, return a Var constructed to reference the tlist item.
* If no match, return NULL.
*
* Cross-check phnullingrels as in search_indexed_tlist_for_var.
*
* NOTE: it is a waste of time to call this unless itlist->has_ph_vars.
*/
static Var *
search_indexed_tlist_for_phv(PlaceHolderVar *phv,
indexed_tlist *itlist, int newvarno,
NullingRelsMatch nrm_match)
{
ListCell *lc;
foreach(lc, itlist->tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
if (tle->expr && IsA(tle->expr, PlaceHolderVar))
{
PlaceHolderVar *subphv = (PlaceHolderVar *) tle->expr;
Var *newvar;
/*
* Analogously to search_indexed_tlist_for_var, we match on phid
* only. We don't use equal(), partially for speed but mostly
* because phnullingrels might not be exactly equal.
*/
if (phv->phid != subphv->phid)
continue;
/* Verify that we kept all the nullingrels machinations straight */
if (!(nrm_match == NRM_SUBSET ?
bms_is_subset(phv->phnullingrels, subphv->phnullingrels) :
nrm_match == NRM_SUPERSET ?
bms_is_subset(subphv->phnullingrels, phv->phnullingrels) :
bms_equal(subphv->phnullingrels, phv->phnullingrels)))
elog(ERROR, "wrong phnullingrels %s (expected %s) for PlaceHolderVar %d",
bmsToString(phv->phnullingrels),
bmsToString(subphv->phnullingrels),
phv->phid);
/* Found a matching subplan output expression */
newvar = makeVarFromTargetEntry(newvarno, tle);
newvar->varnosyn = 0; /* wasn't ever a plain Var */
newvar->varattnosyn = 0;
return newvar;
}
}
return NULL; /* no match */
}
/*
* search_indexed_tlist_for_non_var --- find a non-Var/PHV in an indexed tlist
*
* If a match is found, return a Var constructed to reference the tlist item.
* If no match, return NULL.
*
* NOTE: it is a waste of time to call this unless itlist->has_non_vars.
*/
static Var *
search_indexed_tlist_for_non_var(Expr *node,
indexed_tlist *itlist, int newvarno)
{
TargetEntry *tle;
/*
* If it's a simple Const, replacing it with a Var is silly, even if there
* happens to be an identical Const below; a Var is more expensive to
* execute than a Const. What's more, replacing it could confuse some
* places in the executor that expect to see simple Consts for, eg,
* dropped columns.
*/
if (IsA(node, Const))
return NULL;
tle = tlist_member(node, itlist->tlist);
if (tle)
{
/* Found a matching subplan output expression */
Var *newvar;
newvar = makeVarFromTargetEntry(newvarno, tle);
newvar->varnosyn = 0; /* wasn't ever a plain Var */
newvar->varattnosyn = 0;
return newvar;
}
return NULL; /* no match */
}
/*
* search_indexed_tlist_for_sortgroupref --- find a sort/group expression
*
* If a match is found, return a Var constructed to reference the tlist item.
* If no match, return NULL.
*
* This is needed to ensure that we select the right subplan TLE in cases
* where there are multiple textually-equal()-but-volatile sort expressions.
* And it's also faster than search_indexed_tlist_for_non_var.
*/
static Var *
search_indexed_tlist_for_sortgroupref(Expr *node,
Index sortgroupref,
indexed_tlist *itlist,
int newvarno)
{
ListCell *lc;
foreach(lc, itlist->tlist)
{
TargetEntry *tle = (TargetEntry *) lfirst(lc);
/* The equal() check should be redundant, but let's be paranoid */
if (tle->ressortgroupref == sortgroupref &&
equal(node, tle->expr))
{
/* Found a matching subplan output expression */
Var *newvar;
newvar = makeVarFromTargetEntry(newvarno, tle);
newvar->varnosyn = 0; /* wasn't ever a plain Var */
newvar->varattnosyn = 0;
return newvar;
}
}
return NULL; /* no match */
}
/*
* fix_join_expr
* Create a new set of targetlist entries or join qual clauses by
* changing the varno/varattno values of variables in the clauses
* to reference target list values from the outer and inner join
* relation target lists. Also perform opcode lookup and add
* regclass OIDs to root->glob->relationOids.
*
* This is used in four different scenarios:
* 1) a normal join clause, where all the Vars in the clause *must* be
* replaced by OUTER_VAR or INNER_VAR references. In this case
* acceptable_rel should be zero so that any failure to match a Var will be
* reported as an error.
* 2) RETURNING clauses, which may contain both Vars of the target relation
* and Vars of other relations. In this case we want to replace the
* other-relation Vars by OUTER_VAR references, while leaving target Vars
* alone. Thus inner_itlist = NULL and acceptable_rel = the ID of the
* target relation should be passed.
* 3) ON CONFLICT UPDATE SET/WHERE clauses. Here references to EXCLUDED are
* to be replaced with INNER_VAR references, while leaving target Vars (the
* to-be-updated relation) alone. Correspondingly inner_itlist is to be
* EXCLUDED elements, outer_itlist = NULL and acceptable_rel the target
* relation.
* 4) MERGE. In this case, references to the source relation are to be
* replaced with INNER_VAR references, leaving Vars of the target
* relation (the to-be-modified relation) alone. So inner_itlist is to be
* the source relation elements, outer_itlist = NULL and acceptable_rel
* the target relation.
*
* 'clauses' is the targetlist or list of join clauses
* 'outer_itlist' is the indexed target list of the outer join relation,
* or NULL
* 'inner_itlist' is the indexed target list of the inner join relation,
* or NULL
* 'acceptable_rel' is either zero or the rangetable index of a relation
* whose Vars may appear in the clause without provoking an error
* 'rtoffset': how much to increment varnos by
* 'nrm_match': as for search_indexed_tlist_for_var()
* 'num_exec': estimated number of executions of expression
*
* Returns the new expression tree. The original clause structure is
* not modified.
*/
static List *
fix_join_expr(PlannerInfo *root,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index acceptable_rel,
int rtoffset,
NullingRelsMatch nrm_match,
double num_exec)
{
fix_join_expr_context context;
context.root = root;
context.outer_itlist = outer_itlist;
context.inner_itlist = inner_itlist;
context.acceptable_rel = acceptable_rel;
context.rtoffset = rtoffset;
context.nrm_match = nrm_match;
context.num_exec = num_exec;
return (List *) fix_join_expr_mutator((Node *) clauses, &context);
}
static Node *
fix_join_expr_mutator(Node *node, fix_join_expr_context *context)
{
Var *newvar;
if (node == NULL)
return NULL;
if (IsA(node, Var))
{
Var *var = (Var *) node;
/* Look for the var in the input tlists, first in the outer */
if (context->outer_itlist)
{
newvar = search_indexed_tlist_for_var(var,
context->outer_itlist,
OUTER_VAR,
context->rtoffset,
context->nrm_match);
if (newvar)
return (Node *) newvar;
}
/* then in the inner. */
if (context->inner_itlist)
{
newvar = search_indexed_tlist_for_var(var,
context->inner_itlist,
INNER_VAR,
context->rtoffset,
context->nrm_match);
if (newvar)
return (Node *) newvar;
}
/* If it's for acceptable_rel, adjust and return it */
if (var->varno == context->acceptable_rel)
{
var = copyVar(var);
var->varno += context->rtoffset;
if (var->varnosyn > 0)
var->varnosyn += context->rtoffset;
return (Node *) var;
}
/* No referent found for Var */
elog(ERROR, "variable not found in subplan target lists");
}
if (IsA(node, PlaceHolderVar))
{
PlaceHolderVar *phv = (PlaceHolderVar *) node;
/* See if the PlaceHolderVar has bubbled up from a lower plan node */
if (context->outer_itlist && context->outer_itlist->has_ph_vars)
{
newvar = search_indexed_tlist_for_phv(phv,
context->outer_itlist,
OUTER_VAR,
context->nrm_match);
if (newvar)
return (Node *) newvar;
}
if (context->inner_itlist && context->inner_itlist->has_ph_vars)
{
newvar = search_indexed_tlist_for_phv(phv,
context->inner_itlist,
INNER_VAR,
context->nrm_match);
if (newvar)
return (Node *) newvar;
}
/* If not supplied by input plans, evaluate the contained expr */
/* XXX can we assert something about phnullingrels? */
return fix_join_expr_mutator((Node *) phv->phexpr, context);
}
/* Try matching more complex expressions too, if tlists have any */
if (context->outer_itlist && context->outer_itlist->has_non_vars)
{
newvar = search_indexed_tlist_for_non_var((Expr *) node,
context->outer_itlist,
OUTER_VAR);
if (newvar)
return (Node *) newvar;
}
if (context->inner_itlist && context->inner_itlist->has_non_vars)
{
newvar = search_indexed_tlist_for_non_var((Expr *) node,
context->inner_itlist,
INNER_VAR);
if (newvar)
return (Node *) newvar;
}
/* Special cases (apply only AFTER failing to match to lower tlist) */
if (IsA(node, Param))
return fix_param_node(context->root, (Param *) node);
if (IsA(node, AlternativeSubPlan))
return fix_join_expr_mutator(fix_alternative_subplan(context->root,
(AlternativeSubPlan *) node,
context->num_exec),
context);
fix_expr_common(context->root, node);
return expression_tree_mutator(node,
fix_join_expr_mutator,
(void *) context);
}
/*
* fix_upper_expr
* Modifies an expression tree so that all Var nodes reference outputs
* of a subplan. Also looks for Aggref nodes that should be replaced
* by initplan output Params. Also performs opcode lookup, and adds
* regclass OIDs to root->glob->relationOids.
*
* This is used to fix up target and qual expressions of non-join upper-level
* plan nodes, as well as index-only scan nodes.
*
* An error is raised if no matching var can be found in the subplan tlist
* --- so this routine should only be applied to nodes whose subplans'
* targetlists were generated by flattening the expressions used in the
* parent node.
*
* If itlist->has_non_vars is true, then we try to match whole subexpressions
* against elements of the subplan tlist, so that we can avoid recomputing
* expressions that were already computed by the subplan. (This is relatively
* expensive, so we don't want to try it in the common case where the
* subplan tlist is just a flattened list of Vars.)
*
* 'node': the tree to be fixed (a target item or qual)
* 'subplan_itlist': indexed target list for subplan (or index)
* 'newvarno': varno to use for Vars referencing tlist elements
* 'rtoffset': how much to increment varnos by
* 'nrm_match': as for search_indexed_tlist_for_var()
* 'num_exec': estimated number of executions of expression
*
* The resulting tree is a copy of the original in which all Var nodes have
* varno = newvarno, varattno = resno of corresponding targetlist element.
* The original tree is not modified.
*/
static Node *
fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
int newvarno,
int rtoffset,
NullingRelsMatch nrm_match,
double num_exec)
{
fix_upper_expr_context context;
context.root = root;
context.subplan_itlist = subplan_itlist;
context.newvarno = newvarno;
context.rtoffset = rtoffset;
context.nrm_match = nrm_match;
context.num_exec = num_exec;
return fix_upper_expr_mutator(node, &context);
}
static Node *
fix_upper_expr_mutator(Node *node, fix_upper_expr_context *context)
{
Var *newvar;
if (node == NULL)
return NULL;
if (IsA(node, Var))
{
Var *var = (Var *) node;
newvar = search_indexed_tlist_for_var(var,
context->subplan_itlist,
context->newvarno,
context->rtoffset,
context->nrm_match);
if (!newvar)
elog(ERROR, "variable not found in subplan target list");
return (Node *) newvar;
}
if (IsA(node, PlaceHolderVar))
{
PlaceHolderVar *phv = (PlaceHolderVar *) node;
/* See if the PlaceHolderVar has bubbled up from a lower plan node */
if (context->subplan_itlist->has_ph_vars)
{
newvar = search_indexed_tlist_for_phv(phv,
context->subplan_itlist,
context->newvarno,
context->nrm_match);
if (newvar)
return (Node *) newvar;
}
/* If not supplied by input plan, evaluate the contained expr */
/* XXX can we assert something about phnullingrels? */
return fix_upper_expr_mutator((Node *) phv->phexpr, context);
}
/* Try matching more complex expressions too, if tlist has any */
if (context->subplan_itlist->has_non_vars)
{
newvar = search_indexed_tlist_for_non_var((Expr *) node,
context->subplan_itlist,
context->newvarno);
if (newvar)
return (Node *) newvar;
}
/* Special cases (apply only AFTER failing to match to lower tlist) */
if (IsA(node, Param))
return fix_param_node(context->root, (Param *) node);
if (IsA(node, Aggref))
{
Aggref *aggref = (Aggref *) node;
/* See if the Aggref should be replaced by a Param */
if (context->root->minmax_aggs != NIL &&
list_length(aggref->args) == 1)
{
TargetEntry *curTarget = (TargetEntry *) linitial(aggref->args);
ListCell *lc;
foreach(lc, context->root->minmax_aggs)
{
MinMaxAggInfo *mminfo = (MinMaxAggInfo *) lfirst(lc);
if (mminfo->aggfnoid == aggref->aggfnoid &&
equal(mminfo->target, curTarget->expr))
return (Node *) copyObject(mminfo->param);
}
}
/* If no match, just fall through to process it normally */
}
if (IsA(node, AlternativeSubPlan))
return fix_upper_expr_mutator(fix_alternative_subplan(context->root,
(AlternativeSubPlan *) node,
context->num_exec),
context);
fix_expr_common(context->root, node);
return expression_tree_mutator(node,
fix_upper_expr_mutator,
(void *) context);
}
/*
* set_returning_clause_references
* Perform setrefs.c's work on a RETURNING targetlist
*
* If the query involves more than just the result table, we have to
* adjust any Vars that refer to other tables to reference junk tlist
* entries in the top subplan's targetlist. Vars referencing the result
* table should be left alone, however (the executor will evaluate them
* using the actual heap tuple, after firing triggers if any). In the
* adjusted RETURNING list, result-table Vars will have their original
* varno (plus rtoffset), but Vars for other rels will have varno OUTER_VAR.
*
* We also must perform opcode lookup and add regclass OIDs to
* root->glob->relationOids.
*
* 'rlist': the RETURNING targetlist to be fixed
* 'topplan': the top subplan node that will be just below the ModifyTable
* node (note it's not yet passed through set_plan_refs)
* 'resultRelation': RT index of the associated result relation
* 'rtoffset': how much to increment varnos by
*
* Note: the given 'root' is for the parent query level, not the 'topplan'.
* This does not matter currently since we only access the dependency-item
* lists in root->glob, but it would need some hacking if we wanted a root
* that actually matches the subplan.
*
* Note: resultRelation is not yet adjusted by rtoffset.
*/
static List *
set_returning_clause_references(PlannerInfo *root,
List *rlist,
Plan *topplan,
Index resultRelation,
int rtoffset)
{
indexed_tlist *itlist;
/*
* We can perform the desired Var fixup by abusing the fix_join_expr
* machinery that formerly handled inner indexscan fixup. We search the
* top plan's targetlist for Vars of non-result relations, and use
* fix_join_expr to convert RETURNING Vars into references to those tlist
* entries, while leaving result-rel Vars as-is.
*
* PlaceHolderVars will also be sought in the targetlist, but no
* more-complex expressions will be. Note that it is not possible for a
* PlaceHolderVar to refer to the result relation, since the result is
* never below an outer join. If that case could happen, we'd have to be
* prepared to pick apart the PlaceHolderVar and evaluate its contained
* expression instead.
*/
itlist = build_tlist_index_other_vars(topplan->targetlist, resultRelation);
rlist = fix_join_expr(root,
rlist,
itlist,
NULL,
resultRelation,
rtoffset,
NRM_EQUAL,
NUM_EXEC_TLIST(topplan));
pfree(itlist);
return rlist;
}
/*
* fix_windowagg_condition_expr_mutator
* Mutator function for replacing WindowFuncs with the corresponding Var
* in the targetlist which references that WindowFunc.
*/
static Node *
fix_windowagg_condition_expr_mutator(Node *node,
fix_windowagg_cond_context *context)
{
if (node == NULL)
return NULL;
if (IsA(node, WindowFunc))
{
Var *newvar;
newvar = search_indexed_tlist_for_non_var((Expr *) node,
context->subplan_itlist,
context->newvarno);
if (newvar)
return (Node *) newvar;
elog(ERROR, "WindowFunc not found in subplan target lists");
}
return expression_tree_mutator(node,
fix_windowagg_condition_expr_mutator,
(void *) context);
}
/*
* fix_windowagg_condition_expr
* Converts references in 'runcondition' so that any WindowFunc
* references are swapped out for a Var which references the matching
* WindowFunc in 'subplan_itlist'.
*/
static List *
fix_windowagg_condition_expr(PlannerInfo *root,
List *runcondition,
indexed_tlist *subplan_itlist)
{
fix_windowagg_cond_context context;
context.root = root;
context.subplan_itlist = subplan_itlist;
context.newvarno = 0;
return (List *) fix_windowagg_condition_expr_mutator((Node *) runcondition,
&context);
}
/*
* set_windowagg_runcondition_references
* Converts references in 'runcondition' so that any WindowFunc
* references are swapped out for a Var which references the matching
* WindowFunc in 'plan' targetlist.
*/
static List *
set_windowagg_runcondition_references(PlannerInfo *root,
List *runcondition,
Plan *plan)
{
List *newlist;
indexed_tlist *itlist;
itlist = build_tlist_index(plan->targetlist);
newlist = fix_windowagg_condition_expr(root, runcondition, itlist);
pfree(itlist);
return newlist;
}
/*****************************************************************************
* QUERY DEPENDENCY MANAGEMENT
*****************************************************************************/
/*
* record_plan_function_dependency
* Mark the current plan as depending on a particular function.
*
* This is exported so that the function-inlining code can record a
* dependency on a function that it's removed from the plan tree.
*/
void
record_plan_function_dependency(PlannerInfo *root, Oid funcid)
{
/*
* For performance reasons, we don't bother to track built-in functions;
* we just assume they'll never change (or at least not in ways that'd
* invalidate plans using them). For this purpose we can consider a
* built-in function to be one with OID less than FirstUnpinnedObjectId.
* Note that the OID generator guarantees never to generate such an OID
* after startup, even at OID wraparound.
*/
if (funcid >= (Oid) FirstUnpinnedObjectId)
{
PlanInvalItem *inval_item = makeNode(PlanInvalItem);
/*
* It would work to use any syscache on pg_proc, but the easiest is
* PROCOID since we already have the function's OID at hand. Note
* that plancache.c knows we use PROCOID.
*/
inval_item->cacheId = PROCOID;
inval_item->hashValue = GetSysCacheHashValue1(PROCOID,
ObjectIdGetDatum(funcid));
root->glob->invalItems = lappend(root->glob->invalItems, inval_item);
}
}
/*
* record_plan_type_dependency
* Mark the current plan as depending on a particular type.
*
* This is exported so that eval_const_expressions can record a
* dependency on a domain that it's removed a CoerceToDomain node for.
*
* We don't currently need to record dependencies on domains that the
* plan contains CoerceToDomain nodes for, though that might change in
* future. Hence, this isn't actually called in this module, though
* someday fix_expr_common might call it.
*/
void
record_plan_type_dependency(PlannerInfo *root, Oid typid)
{
/*
* As in record_plan_function_dependency, ignore the possibility that
* someone would change a built-in domain.
*/
if (typid >= (Oid) FirstUnpinnedObjectId)
{
PlanInvalItem *inval_item = makeNode(PlanInvalItem);
/*
* It would work to use any syscache on pg_type, but the easiest is
* TYPEOID since we already have the type's OID at hand. Note that
* plancache.c knows we use TYPEOID.
*/
inval_item->cacheId = TYPEOID;
inval_item->hashValue = GetSysCacheHashValue1(TYPEOID,
ObjectIdGetDatum(typid));
root->glob->invalItems = lappend(root->glob->invalItems, inval_item);
}
}
/*
* extract_query_dependencies
* Given a rewritten, but not yet planned, query or queries
* (i.e. a Query node or list of Query nodes), extract dependencies
* just as set_plan_references would do. Also detect whether any
* rewrite steps were affected by RLS.
*
* This is needed by plancache.c to handle invalidation of cached unplanned
* queries.
*
* Note: this does not go through eval_const_expressions, and hence doesn't
* reflect its additions of inlined functions and elided CoerceToDomain nodes
* to the invalItems list. This is obviously OK for functions, since we'll
* see them in the original query tree anyway. For domains, it's OK because
* we don't care about domains unless they get elided. That is, a plan might
* have domain dependencies that the query tree doesn't.
*/
void
extract_query_dependencies(Node *query,
List **relationOids,
List **invalItems,
bool *hasRowSecurity)
{
PlannerGlobal glob;
PlannerInfo root;
/* Make up dummy planner state so we can use this module's machinery */
MemSet(&glob, 0, sizeof(glob));
glob.type = T_PlannerGlobal;
glob.relationOids = NIL;
glob.invalItems = NIL;
/* Hack: we use glob.dependsOnRole to collect hasRowSecurity flags */
glob.dependsOnRole = false;
MemSet(&root, 0, sizeof(root));
root.type = T_PlannerInfo;
root.glob = &glob;
(void) extract_query_dependencies_walker(query, &root);
*relationOids = glob.relationOids;
*invalItems = glob.invalItems;
*hasRowSecurity = glob.dependsOnRole;
}
/*
* Tree walker for extract_query_dependencies.
*
* This is exported so that expression_planner_with_deps can call it on
* simple expressions (post-planning, not before planning, in that case).
* In that usage, glob.dependsOnRole isn't meaningful, but the relationOids
* and invalItems lists are added to as needed.
*/
bool
extract_query_dependencies_walker(Node *node, PlannerInfo *context)
{
if (node == NULL)
return false;
Assert(!IsA(node, PlaceHolderVar));
if (IsA(node, Query))
{
Query *query = (Query *) node;
ListCell *lc;
if (query->commandType == CMD_UTILITY)
{
/*
* Ignore utility statements, except those (such as EXPLAIN) that
* contain a parsed-but-not-planned query.
*/
query = UtilityContainsQuery(query->utilityStmt);
if (query == NULL)
return false;
}
/* Remember if any Query has RLS quals applied by rewriter */
if (query->hasRowSecurity)
context->glob->dependsOnRole = true;
/* Collect relation OIDs in this Query's rtable */
foreach(lc, query->rtable)
{
RangeTblEntry *rte = (RangeTblEntry *) lfirst(lc);
if (rte->rtekind == RTE_RELATION ||
(rte->rtekind == RTE_SUBQUERY && OidIsValid(rte->relid)) ||
(rte->rtekind == RTE_NAMEDTUPLESTORE && OidIsValid(rte->relid)))
context->glob->relationOids =
lappend_oid(context->glob->relationOids, rte->relid);
}
/* And recurse into the query's subexpressions */
return query_tree_walker(query, extract_query_dependencies_walker,
(void *) context, 0);
}
/* Extract function dependencies and check for regclass Consts */
fix_expr_common(context, node);
return expression_tree_walker(node, extract_query_dependencies_walker,
(void *) context);
}
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