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/*-------------------------------------------------------------------------
*
* fdwapi.h
* API for foreign-data wrappers
*
* Copyright (c) 2010-2012, PostgreSQL Global Development Group
*
* src/include/foreign/fdwapi.h
*
*-------------------------------------------------------------------------
*/
#ifndef FDWAPI_H
#define FDWAPI_H
#include "nodes/execnodes.h"
#include "nodes/relation.h"
/* To avoid including explain.h here, reference ExplainState thus: */
struct ExplainState;
/*
* Callback function signatures --- see fdwhandler.sgml for more info.
*/
typedef void (*GetForeignRelSize_function) (PlannerInfo *root,
RelOptInfo *baserel,
Oid foreigntableid);
typedef void (*GetForeignPaths_function) (PlannerInfo *root,
RelOptInfo *baserel,
Oid foreigntableid);
typedef ForeignScan *(*GetForeignPlan_function) (PlannerInfo *root,
RelOptInfo *baserel,
Oid foreigntableid,
ForeignPath *best_path,
List *tlist,
List *scan_clauses);
typedef void (*ExplainForeignScan_function) (ForeignScanState *node,
struct ExplainState *es);
typedef void (*BeginForeignScan_function) (ForeignScanState *node,
int eflags);
typedef TupleTableSlot *(*IterateForeignScan_function) (ForeignScanState *node);
typedef void (*ReScanForeignScan_function) (ForeignScanState *node);
typedef void (*EndForeignScan_function) (ForeignScanState *node);
typedef int (*AcquireSampleRowsFunc) (Relation relation, int elevel,
HeapTuple *rows, int targrows,
double *totalrows,
double *totaldeadrows);
typedef bool (*AnalyzeForeignTable_function) (Relation relation,
AcquireSampleRowsFunc *func,
BlockNumber *totalpages);
/*
* FdwRoutine is the struct returned by a foreign-data wrapper's handler
* function. It provides pointers to the callback functions needed by the
* planner and executor.
*
* More function pointers are likely to be added in the future. Therefore
* it's recommended that the handler initialize the struct with
* makeNode(FdwRoutine) so that all fields are set to NULL. This will
* ensure that no fields are accidentally left undefined.
*/
typedef struct FdwRoutine
{
NodeTag type;
/*
* These functions are required.
*/
GetForeignRelSize_function GetForeignRelSize;
GetForeignPaths_function GetForeignPaths;
GetForeignPlan_function GetForeignPlan;
ExplainForeignScan_function ExplainForeignScan;
BeginForeignScan_function BeginForeignScan;
IterateForeignScan_function IterateForeignScan;
ReScanForeignScan_function ReScanForeignScan;
EndForeignScan_function EndForeignScan;
/*
* These functions are optional. Set the pointer to NULL for any
* that are not provided.
*/
AnalyzeForeignTable_function AnalyzeForeignTable;
} FdwRoutine;
/* Functions in foreign/foreign.c */
extern FdwRoutine *GetFdwRoutine(Oid fdwhandler);
extern FdwRoutine *GetFdwRoutineByRelId(Oid relid);
#endif /* FDWAPI_H */
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