optimizer.h

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/*-------------------------------------------------------------------------
 *
 * optimizer.h
 *    External API for the Postgres planner.
 *
 * This header is meant to define everything that the core planner
 * exposes for use by non-planner modules.
 *
 * Note that there are files outside src/backend/optimizer/ that are
 * considered planner modules, because they're too much in bed with
 * planner operations to be treated otherwise.  FDW planning code is an
 * example.  For the most part, however, code outside the core planner
 * should not need to include any optimizer/ header except this one.
 *
 * Portions Copyright (c) 1996-2020, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/optimizer/optimizer.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef OPTIMIZER_H
#define OPTIMIZER_H

#include "nodes/parsenodes.h"

/*
 * We don't want to include nodes/pathnodes.h here, because non-planner
 * code should generally treat PlannerInfo as an opaque typedef.
 * But we'd like such code to use that typedef name, so define the
 * typedef either here or in pathnodes.h, whichever is read first.
 */
#ifndef HAVE_PLANNERINFO_TYPEDEF
typedef struct PlannerInfo PlannerInfo;
#define HAVE_PLANNERINFO_TYPEDEF 1
#endif

/* Likewise for IndexOptInfo and SpecialJoinInfo. */
#ifndef HAVE_INDEXOPTINFO_TYPEDEF
typedef struct IndexOptInfo IndexOptInfo;
#define HAVE_INDEXOPTINFO_TYPEDEF 1
#endif
#ifndef HAVE_SPECIALJOININFO_TYPEDEF
typedef struct SpecialJoinInfo SpecialJoinInfo;
#define HAVE_SPECIALJOININFO_TYPEDEF 1
#endif

/* It also seems best not to include plannodes.h, params.h, or htup.h here */
struct PlannedStmt;
struct ParamListInfoData;
struct HeapTupleData;


/* in path/clausesel.c: */

extern Selectivity clause_selectivity(PlannerInfo *root,
                                      Node *clause,
                                      int varRelid,
                                      JoinType jointype,
                                      SpecialJoinInfo *sjinfo);
extern Selectivity clauselist_selectivity_simple(PlannerInfo *root,
                                                 List *clauses,
                                                 int varRelid,
                                                 JoinType jointype,
                                                 SpecialJoinInfo *sjinfo,
                                                 Bitmapset *estimatedclauses);
extern Selectivity clauselist_selectivity(PlannerInfo *root,
                                          List *clauses,
                                          int varRelid,
                                          JoinType jointype,
                                          SpecialJoinInfo *sjinfo);

/* in path/costsize.c: */

/* widely used cost parameters */
extern PGDLLIMPORT double seq_page_cost;
extern PGDLLIMPORT double random_page_cost;
extern PGDLLIMPORT double cpu_tuple_cost;
extern PGDLLIMPORT double cpu_index_tuple_cost;
extern PGDLLIMPORT double cpu_operator_cost;
extern PGDLLIMPORT double parallel_tuple_cost;
extern PGDLLIMPORT double parallel_setup_cost;
extern PGDLLIMPORT int effective_cache_size;

extern double clamp_row_est(double nrows);

/* in path/indxpath.c: */

extern bool is_pseudo_constant_for_index(Node *expr, IndexOptInfo *index);

/* in plan/planner.c: */

/* possible values for force_parallel_mode */
typedef enum
{
    FORCE_PARALLEL_OFF,
    FORCE_PARALLEL_ON,
    FORCE_PARALLEL_REGRESS
}           ForceParallelMode;

/* GUC parameters */
extern int  force_parallel_mode;
extern bool parallel_leader_participation;

extern struct PlannedStmt *planner(Query *parse, int cursorOptions,
                                   struct ParamListInfoData *boundParams);

extern Expr *expression_planner(Expr *expr);
extern Expr *expression_planner_with_deps(Expr *expr,
                                          List **relationOids,
                                          List **invalItems);

extern bool plan_cluster_use_sort(Oid tableOid, Oid indexOid);
extern int  plan_create_index_workers(Oid tableOid, Oid indexOid);

/* in plan/setrefs.c: */

extern void extract_query_dependencies(Node *query,
                                       List **relationOids,
                                       List **invalItems,
                                       bool *hasRowSecurity);

/* in prep/prepqual.c: */

extern Node *negate_clause(Node *node);
extern Expr *canonicalize_qual(Expr *qual, bool is_check);

/* in util/clauses.c: */

extern bool contain_mutable_functions(Node *clause);
extern bool contain_volatile_functions(Node *clause);
extern bool contain_volatile_functions_not_nextval(Node *clause);

extern Node *eval_const_expressions(PlannerInfo *root, Node *node);

extern Node *estimate_expression_value(PlannerInfo *root, Node *node);

extern Expr *evaluate_expr(Expr *expr, Oid result_type, int32 result_typmod,
                           Oid result_collation);

extern List *expand_function_arguments(List *args, Oid result_type,
                                       struct HeapTupleData *func_tuple);

/* in util/predtest.c: */

extern bool predicate_implied_by(List *predicate_list, List *clause_list,
                                 bool weak);
extern bool predicate_refuted_by(List *predicate_list, List *clause_list,
                                 bool weak);

/* in util/tlist.c: */

extern int  count_nonjunk_tlist_entries(List *tlist);
extern TargetEntry *get_sortgroupref_tle(Index sortref,
                                         List *targetList);
extern TargetEntry *get_sortgroupclause_tle(SortGroupClause *sgClause,
                                            List *targetList);
extern Node *get_sortgroupclause_expr(SortGroupClause *sgClause,
                                      List *targetList);
extern List *get_sortgrouplist_exprs(List *sgClauses,
                                     List *targetList);
extern SortGroupClause *get_sortgroupref_clause(Index sortref,
                                                List *clauses);
extern SortGroupClause *get_sortgroupref_clause_noerr(Index sortref,
                                                      List *clauses);

/* in util/var.c: */

/* Bits that can be OR'd into the flags argument of pull_var_clause() */
#define PVC_INCLUDE_AGGREGATES  0x0001  /* include Aggrefs in output list */
#define PVC_RECURSE_AGGREGATES  0x0002  /* recurse into Aggref arguments */
#define PVC_INCLUDE_WINDOWFUNCS 0x0004  /* include WindowFuncs in output list */
#define PVC_RECURSE_WINDOWFUNCS 0x0008  /* recurse into WindowFunc arguments */
#define PVC_INCLUDE_PLACEHOLDERS    0x0010  /* include PlaceHolderVars in
                                             * output list */
#define PVC_RECURSE_PLACEHOLDERS    0x0020  /* recurse into PlaceHolderVar
                                             * arguments */

extern Bitmapset *pull_varnos(Node *node);
extern Bitmapset *pull_varnos_of_level(Node *node, int levelsup);
extern void pull_varattnos(Node *node, Index varno, Bitmapset **varattnos);
extern List *pull_vars_of_level(Node *node, int levelsup);
extern bool contain_var_clause(Node *node);
extern bool contain_vars_of_level(Node *node, int levelsup);
extern int  locate_var_of_level(Node *node, int levelsup);
extern List *pull_var_clause(Node *node, int flags);
extern Node *flatten_join_alias_vars(Query *query, Node *node);

#endif                          /* OPTIMIZER_H */