vops_fdw.h

/*-------------------------------------------------------------------------
 *
 * postgres_fdw.h
 *		  Foreign-data wrapper for remote PostgreSQL servers
 *
 * Portions Copyright (c) 2012-2017, 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"
#if PG_VERSION_NUM>=120000
#include "nodes/pathnodes.h"
#else
#include "nodes/relation.h"
#endif
#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
{
	/*
	 * True means that the relation can be pushed down. Always true for simple
	 * foreign scan.
	 */
	bool		pushdown_safe;

	/*
	 * Restriction clauses, divided into safe and unsafe to pushdown subsets.
	 *
	 * For a base foreign relation this is a list of clauses along-with
	 * RestrictInfo wrapper. Keeping RestrictInfo wrapper helps while dividing
	 * scan_clauses in postgresGetForeignPlan into safe and unsafe subsets.
	 * Also it helps in estimating costs since RestrictInfo caches the
	 * selectivity and qual cost for the clause in it.
	 *
	 * For a join relation, however, they are part of otherclause list
	 * obtained from extract_actual_join_clauses, which strips RestrictInfo
	 * construct. So, for a join relation they are list of bare clauses.
	 */
	List	   *remote_conds;
	List	   *local_conds;

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

	/* Bitmap of VOPS attributes (attributes available in VOPS projection) */
	Bitmapset  *vops_attrs;

	/* Bitmap of VOPS tile attributes (attributes represented by tiles in VOPS projection) */
	Bitmapset  *tile_attrs;

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

	/* Estimated size and cost for a scan or join. */
	double		rows;
	int			width;
	Cost		startup_cost;
	Cost		total_cost;
	/* Costs excluding costs for transferring data from the foreign server */
	Cost		rel_startup_cost;
	Cost		rel_total_cost;

	/* Cached catalog information. */
	ForeignTable *table;
	ForeignServer *server;

	/*
	 * Name of the relation while EXPLAINing ForeignScan. It is used for join
	 * relations but is set for all relations. For join relation, the name
	 * indicates which foreign tables are being joined and the join type used.
	 */
	StringInfo	relation_name;

	/* Grouping information */
	RelOptInfo *upperrel;
	List	   *grouped_tlist;
} PgFdwRelationInfo;

extern void vopsClassifyConditions(PlannerInfo *root,
							   RelOptInfo *baserel,
							   List *input_conds,
							   List **remote_conds,
							   List **local_conds);
extern bool vops_is_foreign_expr(PlannerInfo *root,
							RelOptInfo *baserel,
							Expr *expr);
extern List *vops_build_tlist_to_deparse(RelOptInfo *foreignrel);
extern void vopsDeparseSelectStmtForRel(StringInfo buf, PlannerInfo *root,
						RelOptInfo *foreignrel, List *tlist,
						List *remote_conds, List *pathkeys,
						List **retrieved_attrs, List **params_list);
extern char *vops_deparse_type_name(Oid type_oid, int32 typemod);
extern void vopsDeparseRelation(StringInfo buf, Relation rel);

#endif   /* POSTGRES_FDW_H */