postgres_fdw.h

/*-------------------------------------------------------------------------
 *
 * postgres_fdw.h
 *		  Foreign-data wrapper for remote PostgreSQL servers
 *
 * Portions Copyright (c) 2012-2016, PostgreSQL Global Development Group
 *
 * IDENTIFICATION
 *		  contrib/postgres_fdw/postgres_fdw.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef POSTGRES_FDW_H
#define POSTGRES_FDW_H

#include "foreign/foreign.h"
#include "lib/stringinfo.h"
#include "nodes/relation.h"
#include "utils/relcache.h"

#include "libpq-fe.h"

/*
 * FDW-specific planner information kept in RelOptInfo.fdw_private for a
 * foreign table.  This information is collected by postgresGetForeignRelSize.
 */
typedef struct PgFdwRelationInfo
{
	/* baserestrictinfo clauses, broken down into safe and unsafe subsets. */
	List	   *remote_conds;
	List	   *local_conds;

	/* Bitmap of attr numbers we need to fetch from the remote server. */
	Bitmapset  *attrs_used;

	/* Cost and selectivity of local_conds. */
	QualCost	local_conds_cost;
	Selectivity local_conds_sel;

	/* Estimated size and cost for a scan with baserestrictinfo quals. */
	double		rows;
	int			width;
	Cost		startup_cost;
	Cost		total_cost;

	/* Options extracted from catalogs. */
	bool		use_remote_estimate;
	Cost		fdw_startup_cost;
	Cost		fdw_tuple_cost;
	List	   *shippable_extensions;	/* OIDs of whitelisted extensions */

	/* Cached catalog information. */
	ForeignTable *table;
	ForeignServer *server;
	UserMapping *user;			/* only set in use_remote_estimate mode */

	int			fetch_size;      /* fetch size for this remote table */
} PgFdwRelationInfo;

/* in postgres_fdw.c */
extern int	set_transmission_modes(void);
extern void reset_transmission_modes(int nestlevel);

/* in connection.c */
extern PGconn *GetConnection(UserMapping *user, bool will_prep_stmt);
extern void ReleaseConnection(PGconn *conn);
extern unsigned int GetCursorNumber(PGconn *conn);
extern unsigned int GetPrepStmtNumber(PGconn *conn);
extern void pgfdw_report_error(int elevel, PGresult *res, PGconn *conn,
				   bool clear, const char *sql);

/* in option.c */
extern int ExtractConnectionOptions(List *defelems,
						 const char **keywords,
						 const char **values);
extern List *ExtractExtensionList(const char *extensionsString,
					 bool warnOnMissing);

/* in deparse.c */
extern void classifyConditions(PlannerInfo *root,
				   RelOptInfo *baserel,
				   List *input_conds,
				   List **remote_conds,
				   List **local_conds);
extern bool is_foreign_expr(PlannerInfo *root,
				RelOptInfo *baserel,
				Expr *expr);
extern void deparseInsertSql(StringInfo buf, PlannerInfo *root,
				 Index rtindex, Relation rel,
				 List *targetAttrs, bool doNothing, List *returningList,
				 List **retrieved_attrs);
extern void deparseUpdateSql(StringInfo buf, PlannerInfo *root,
				 Index rtindex, Relation rel,
				 List *targetAttrs, List *returningList,
				 List **retrieved_attrs);
extern void deparseDeleteSql(StringInfo buf, PlannerInfo *root,
				 Index rtindex, Relation rel,
				 List *returningList,
				 List **retrieved_attrs);
extern void deparseAnalyzeSizeSql(StringInfo buf, Relation rel);
extern void deparseAnalyzeSql(StringInfo buf, Relation rel,
				  List **retrieved_attrs);
extern void deparseStringLiteral(StringInfo buf, const char *val);
extern Expr *find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel);
extern void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root,
					 RelOptInfo *baserel, List *remote_conds, List *pathkeys,
						List **retrieved_attrs, List **params_list);

/* in shippable.c */
extern bool is_builtin(Oid objectId);
extern bool is_shippable(Oid objectId, Oid classId, PgFdwRelationInfo *fpinfo);

#endif   /* POSTGRES_FDW_H */