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/*-------------------------------------------------------------------------
*
* plannodes.h
* definitions for query plan nodes
*
*
* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* $Id: plannodes.h,v 1.71 2003/11/25 21:00:54 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#ifndef PLANNODES_H
#define PLANNODES_H
#include "access/sdir.h"
#include "nodes/bitmapset.h"
#include "nodes/primnodes.h"
/* ----------------------------------------------------------------
* node definitions
* ----------------------------------------------------------------
*/
/* ----------------
* Plan node
*
* All plan nodes "derive" from the Plan structure by having the
* Plan structure as the first field. This ensures that everything works
* when nodes are cast to Plan's. (node pointers are frequently cast to Plan*
* when passed around generically in the executor)
*
* We never actually instantiate any Plan nodes; this is just the common
* abstract superclass for all Plan-type nodes.
* ----------------
*/
typedef struct Plan
{
NodeTag type;
/*
* estimated execution costs for plan (see costsize.c for more info)
*/
Cost startup_cost; /* cost expended before fetching any
* tuples */
Cost total_cost; /* total cost (assuming all tuples
* fetched) */
/*
* planner's estimate of result size of this plan step
*/
double plan_rows; /* number of rows plan is expected to emit */
int plan_width; /* average row width in bytes */
/*
* Common structural data for all Plan types.
*/
List *targetlist; /* target list to be computed at this node */
List *qual; /* implicitly-ANDed qual conditions */
struct Plan *lefttree; /* input plan tree(s) */
struct Plan *righttree;
List *initPlan; /* Init Plan nodes (un-correlated expr
* subselects) */
/*
* Information for management of parameter-change-driven rescanning
*
* extParam includes the paramIDs of all external PARAM_EXEC params
* affecting this plan node or its children. setParam params from the
* node's initPlans are not included, but their extParams are.
*
* allParam includes all the extParam paramIDs, plus the IDs of local
* params that affect the node (i.e., the setParams of its initplans).
* These are _all_ the PARAM_EXEC params that affect this node.
*/
Bitmapset *extParam;
Bitmapset *allParam;
/*
* We really need in some TopPlan node to store range table and
* resultRelation from Query there and get rid of Query itself from
* Executor. Some other stuff like below could be put there, too.
*/
int nParamExec; /* Number of them in entire query. This is
* to get Executor know about how many
* param_exec there are in query plan. */
} Plan;
/* ----------------
* these are are defined to avoid confusion problems with "left"
* and "right" and "inner" and "outer". The convention is that
* the "left" plan is the "outer" plan and the "right" plan is
* the inner plan, but these make the code more readable.
* ----------------
*/
#define innerPlan(node) (((Plan *)(node))->righttree)
#define outerPlan(node) (((Plan *)(node))->lefttree)
/* ----------------
* Result node -
* If no outer plan, evaluate a variable-free targetlist.
* If outer plan, return tuples from outer plan (after a level of
* projection as shown by targetlist).
*
* If resconstantqual isn't NULL, it represents a one-time qualification
* test (i.e., one that doesn't depend on any variables from the outer plan,
* so needs to be evaluated only once).
* ----------------
*/
typedef struct Result
{
Plan plan;
Node *resconstantqual;
} Result;
/* ----------------
* Append node -
* Generate the concatenation of the results of sub-plans.
*
* Append nodes are sometimes used to switch between several result relations
* (when the target of an UPDATE or DELETE is an inheritance set). Such a
* node will have isTarget true. The Append executor is then responsible
* for updating the executor state to point at the correct target relation
* whenever it switches subplans.
* ----------------
*/
typedef struct Append
{
Plan plan;
List *appendplans;
bool isTarget;
} Append;
/*
* ==========
* Scan nodes
* ==========
*/
typedef struct Scan
{
Plan plan;
Index scanrelid; /* relid is index into the range table */
} Scan;
/* ----------------
* sequential scan node
* ----------------
*/
typedef Scan SeqScan;
/* ----------------
* index scan node
*
* Note: this can actually represent N indexscans, all on the same table
* but potentially using different indexes, put together with OR semantics.
* ----------------
*/
typedef struct IndexScan
{
Scan scan;
List *indxid; /* list of index OIDs (1 per scan) */
List *indxqual; /* list of sublists of index quals */
List *indxqualorig; /* the same in original form */
List *indxstrategy; /* list of sublists of strategy numbers */
List *indxsubtype; /* list of sublists of strategy subtypes */
ScanDirection indxorderdir; /* forward or backward or don't care */
} IndexScan;
/* ----------------
* tid scan node
* ----------------
*/
typedef struct TidScan
{
Scan scan;
List *tideval;
} TidScan;
/* ----------------
* subquery scan node
*
* SubqueryScan is for scanning the output of a sub-query in the range table.
* We need a special plan node above the sub-query's plan as a place to switch
* execution contexts. Although we are not scanning a physical relation,
* we make this a descendant of Scan anyway for code-sharing purposes.
*
* Note: we store the sub-plan in the type-specific subplan field, not in
* the generic lefttree field as you might expect. This is because we do
* not want plan-tree-traversal routines to recurse into the subplan without
* knowing that they are changing Query contexts.
* ----------------
*/
typedef struct SubqueryScan
{
Scan scan;
Plan *subplan;
} SubqueryScan;
/* ----------------
* FunctionScan node
* ----------------
*/
typedef struct FunctionScan
{
Scan scan;
/* no other fields needed at present */
} FunctionScan;
/*
* ==========
* Join nodes
* ==========
*/
/* ----------------
* Join node
*
* jointype: rule for joining tuples from left and right subtrees
* joinqual: qual conditions that came from JOIN/ON or JOIN/USING
* (plan.qual contains conditions that came from WHERE)
*
* When jointype is INNER, joinqual and plan.qual are semantically
* interchangeable. For OUTER jointypes, the two are *not* interchangeable;
* only joinqual is used to determine whether a match has been found for
* the purpose of deciding whether to generate null-extended tuples.
* (But plan.qual is still applied before actually returning a tuple.)
* For an outer join, only joinquals are allowed to be used as the merge
* or hash condition of a merge or hash join.
* ----------------
*/
typedef struct Join
{
Plan plan;
JoinType jointype;
List *joinqual; /* JOIN quals (in addition to plan.qual) */
} Join;
/* ----------------
* nest loop join node
* ----------------
*/
typedef struct NestLoop
{
Join join;
} NestLoop;
/* ----------------
* merge join node
* ----------------
*/
typedef struct MergeJoin
{
Join join;
List *mergeclauses;
} MergeJoin;
/* ----------------
* hash join (probe) node
* ----------------
*/
typedef struct HashJoin
{
Join join;
List *hashclauses;
} HashJoin;
/* ----------------
* materialization node
* ----------------
*/
typedef struct Material
{
Plan plan;
} Material;
/* ----------------
* sort node
* ----------------
*/
typedef struct Sort
{
Plan plan;
int numCols; /* number of sort-key columns */
AttrNumber *sortColIdx; /* their indexes in the target list */
Oid *sortOperators; /* OIDs of operators to sort them by */
} Sort;
/* ---------------
* group node -
* Used for queries with GROUP BY (but no aggregates) specified.
* The input must be presorted according to the grouping columns.
* ---------------
*/
typedef struct Group
{
Plan plan;
int numCols; /* number of grouping columns */
AttrNumber *grpColIdx; /* their indexes in the target list */
} Group;
/* ---------------
* aggregate node
*
* An Agg node implements plain or grouped aggregation. For grouped
* aggregation, we can work with presorted input or unsorted input;
* the latter strategy uses an internal hashtable.
*
* Notice the lack of any direct info about the aggregate functions to be
* computed. They are found by scanning the node's tlist and quals during
* executor startup. (It is possible that there are no aggregate functions;
* this could happen if they get optimized away by constant-folding, or if
* we are using the Agg node to implement hash-based grouping.)
* ---------------
*/
typedef enum AggStrategy
{
AGG_PLAIN, /* simple agg across all input rows */
AGG_SORTED, /* grouped agg, input must be sorted */
AGG_HASHED /* grouped agg, use internal hashtable */
} AggStrategy;
typedef struct Agg
{
Plan plan;
AggStrategy aggstrategy;
int numCols; /* number of grouping columns */
AttrNumber *grpColIdx; /* their indexes in the target list */
long numGroups; /* estimated number of groups in input */
} Agg;
/* ----------------
* unique node
* ----------------
*/
typedef struct Unique
{
Plan plan;
int numCols; /* number of columns to check for
* uniqueness */
AttrNumber *uniqColIdx; /* indexes into the target list */
} Unique;
/* ----------------
* hash build node
* ----------------
*/
typedef struct Hash
{
Plan plan;
/* all other info is in the parent HashJoin node */
} Hash;
/* ----------------
* setop node
* ----------------
*/
typedef enum SetOpCmd
{
SETOPCMD_INTERSECT,
SETOPCMD_INTERSECT_ALL,
SETOPCMD_EXCEPT,
SETOPCMD_EXCEPT_ALL
} SetOpCmd;
typedef struct SetOp
{
Plan plan;
SetOpCmd cmd; /* what to do */
int numCols; /* number of columns to check for
* duplicate-ness */
AttrNumber *dupColIdx; /* indexes into the target list */
AttrNumber flagColIdx;
} SetOp;
/* ----------------
* limit node
* ----------------
*/
typedef struct Limit
{
Plan plan;
Node *limitOffset; /* OFFSET parameter, or NULL if none */
Node *limitCount; /* COUNT parameter, or NULL if none */
} Limit;
#endif /* PLANNODES_H */