postgresql/contrib/postgres_fdw/postgres_fdw.h
Fujii Masao 6e0cb3dec1 postgres_fdw: Allow postgres_fdw.application_name to include escape sequences.
application_name that used when postgres_fdw establishes a connection to
a foreign server can be specified in either or both a connection parameter
of a server object and GUC postgres_fdw.application_name. This commit
allows those parameters to include escape sequences that begins with
% character. Then postgres_fdw replaces those escape sequences with
status information. For example, %d and %u are replaced with user name
and database name in local server, respectively. This feature enables us
to add information more easily to track remote transactions or queries,
into application_name of a remote connection.

Author: Hayato Kuroda
Reviewed-by: Kyotaro Horiguchi, Masahiro Ikeda, Hou Zhijie, Fujii Masao
Discussion: https://postgr.es/m/TYAPR01MB5866FAE71C66547C64616584F5EB9@TYAPR01MB5866.jpnprd01.prod.outlook.com
Discussion: https://postgr.es/m/TYCPR01MB5870D1E8B949DAF6D3B84E02F5F29@TYCPR01MB5870.jpnprd01.prod.outlook.com
2021-12-24 16:55:11 +09:00

236 lines
7.9 KiB
C

/*-------------------------------------------------------------------------
*
* postgres_fdw.h
* Foreign-data wrapper for remote PostgreSQL servers
*
* Portions Copyright (c) 2012-2021, 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 "libpq-fe.h"
#include "nodes/execnodes.h"
#include "nodes/pathnodes.h"
#include "utils/relcache.h"
/*
* FDW-specific planner information kept in RelOptInfo.fdw_private for a
* postgres_fdw foreign table. For a baserel, this struct is created by
* postgresGetForeignRelSize, although some fields are not filled till later.
* postgresGetForeignJoinPaths creates it for a joinrel, and
* postgresGetForeignUpperPaths creates it for an upperrel.
*/
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.
* All entries in these lists should have RestrictInfo wrappers; that
* improves efficiency of selectivity and cost estimation.
*/
List *remote_conds;
List *local_conds;
/* Actual remote restriction clauses for scan (sans RestrictInfos) */
List *final_remote_exprs;
/* Bitmap of attr numbers we need to fetch from the remote server. */
Bitmapset *attrs_used;
/* True means that the query_pathkeys is safe to push down */
bool qp_is_pushdown_safe;
/* Cost and selectivity of local_conds. */
QualCost local_conds_cost;
Selectivity local_conds_sel;
/* Selectivity of join conditions */
Selectivity joinclause_sel;
/* Estimated size and cost for a scan, join, or grouping/aggregation. */
double rows;
int width;
Cost startup_cost;
Cost total_cost;
/*
* Estimated number of rows fetched from the foreign server, and costs
* excluding costs for transferring those rows from the foreign server.
* These are only used by estimate_path_cost_size().
*/
double retrieved_rows;
Cost rel_startup_cost;
Cost rel_total_cost;
/* Options extracted from catalogs. */
bool use_remote_estimate;
Cost fdw_startup_cost;
Cost fdw_tuple_cost;
List *shippable_extensions; /* OIDs of shippable extensions */
bool async_capable;
/* 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 */
/*
* Name of the relation, for use while EXPLAINing ForeignScan. It is used
* for join and upper relations but is set for all relations. For a base
* relation, this is really just the RT index as a string; we convert that
* while producing EXPLAIN output. For join and upper relations, the name
* indicates which base foreign tables are included and the join type or
* aggregation type used.
*/
char *relation_name;
/* Join information */
RelOptInfo *outerrel;
RelOptInfo *innerrel;
JoinType jointype;
/* joinclauses contains only JOIN/ON conditions for an outer join */
List *joinclauses; /* List of RestrictInfo */
/* Upper relation information */
UpperRelationKind stage;
/* Grouping information */
List *grouped_tlist;
/* Subquery information */
bool make_outerrel_subquery; /* do we deparse outerrel as a
* subquery? */
bool make_innerrel_subquery; /* do we deparse innerrel as a
* subquery? */
Relids lower_subquery_rels; /* all relids appearing in lower
* subqueries */
/*
* Index of the relation. It is used to create an alias to a subquery
* representing the relation.
*/
int relation_index;
} PgFdwRelationInfo;
/*
* Extra control information relating to a connection.
*/
typedef struct PgFdwConnState
{
AsyncRequest *pendingAreq; /* pending async request */
} PgFdwConnState;
/* in postgres_fdw.c */
extern int set_transmission_modes(void);
extern void reset_transmission_modes(int nestlevel);
extern void process_pending_request(AsyncRequest *areq);
/* in connection.c */
extern PGconn *GetConnection(UserMapping *user, bool will_prep_stmt,
PgFdwConnState **state);
extern void ReleaseConnection(PGconn *conn);
extern unsigned int GetCursorNumber(PGconn *conn);
extern unsigned int GetPrepStmtNumber(PGconn *conn);
extern void do_sql_command(PGconn *conn, const char *sql);
extern PGresult *pgfdw_get_result(PGconn *conn, const char *query);
extern PGresult *pgfdw_exec_query(PGconn *conn, const char *query,
PgFdwConnState *state);
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);
extern char *process_pgfdw_appname(const char *appname);
extern char *pgfdw_application_name;
/* 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 bool is_foreign_param(PlannerInfo *root,
RelOptInfo *baserel,
Expr *expr);
extern void deparseInsertSql(StringInfo buf, RangeTblEntry *rte,
Index rtindex, Relation rel,
List *targetAttrs, bool doNothing,
List *withCheckOptionList, List *returningList,
List **retrieved_attrs, int *values_end_len);
extern void rebuildInsertSql(StringInfo buf, Relation rel,
char *orig_query, List *target_attrs,
int values_end_len, int num_params,
int num_rows);
extern void deparseUpdateSql(StringInfo buf, RangeTblEntry *rte,
Index rtindex, Relation rel,
List *targetAttrs,
List *withCheckOptionList, List *returningList,
List **retrieved_attrs);
extern void deparseDirectUpdateSql(StringInfo buf, PlannerInfo *root,
Index rtindex, Relation rel,
RelOptInfo *foreignrel,
List *targetlist,
List *targetAttrs,
List *remote_conds,
List **params_list,
List *returningList,
List **retrieved_attrs);
extern void deparseDeleteSql(StringInfo buf, RangeTblEntry *rte,
Index rtindex, Relation rel,
List *returningList,
List **retrieved_attrs);
extern void deparseDirectDeleteSql(StringInfo buf, PlannerInfo *root,
Index rtindex, Relation rel,
RelOptInfo *foreignrel,
List *remote_conds,
List **params_list,
List *returningList,
List **retrieved_attrs);
extern void deparseAnalyzeSizeSql(StringInfo buf, Relation rel);
extern void deparseAnalyzeSql(StringInfo buf, Relation rel,
List **retrieved_attrs);
extern void deparseTruncateSql(StringInfo buf,
List *rels,
DropBehavior behavior,
bool restart_seqs);
extern void deparseStringLiteral(StringInfo buf, const char *val);
extern Expr *find_em_expr_for_rel(EquivalenceClass *ec, RelOptInfo *rel);
extern Expr *find_em_expr_for_input_target(PlannerInfo *root,
EquivalenceClass *ec,
PathTarget *target);
extern List *build_tlist_to_deparse(RelOptInfo *foreignrel);
extern void deparseSelectStmtForRel(StringInfo buf, PlannerInfo *root,
RelOptInfo *foreignrel, List *tlist,
List *remote_conds, List *pathkeys,
bool has_final_sort, bool has_limit,
bool is_subquery,
List **retrieved_attrs, List **params_list);
extern const char *get_jointype_name(JoinType jointype);
/* in shippable.c */
extern bool is_builtin(Oid objectId);
extern bool is_shippable(Oid objectId, Oid classId, PgFdwRelationInfo *fpinfo);
#endif /* POSTGRES_FDW_H */