* Functions returning results from a remote database

*

* Joe Conway <mail@joeconway.com>

* And contributors:

* Darko Prenosil <Darko.Prenosil@finteh.hr>

* Shridhar Daithankar <shridhar_daithankar@persistent.co.in>

*

* Copyright (c) 2001, 2002 by PostgreSQL Global Development Group

* Copyright (c) 2001, 2002, 2003 by PostgreSQL Global Development Group

* ALL RIGHTS RESERVED;

*

* Permission to use, copy, modify, and distribute this software and its

*

*/

Version 0.5 (25 August, 2002):

Major overhaul to work with new backend "table function" capability. Removed

dblink_strtok() and dblink_replace() functions because they are now

available as backend functions (split() and replace() respectively).

Tested under Linux (Red Hat 7.3) and PostgreSQL 7.3devel. This version

is no longer backwards portable to PostgreSQL 7.2.

Version 0.6 (14 June, 2003):

Completely removed previously deprecated functions. Added ability

to create "named" persistent connections in addition to the single global

"unnamed" persistent connection.

Tested under Linux (Red Hat 9) and PostgreSQL 7.4devel.

Release Notes:

Version 0.6

- functions deprecated in 0.5 have been removed

- added ability to create "named" persistent connections

Version 0.5

- dblink now supports use directly as a table function; this is the new

preferred usage going forward

connection

------------

dblink_connect(text) RETURNS text

- opens a connection that will persist for duration of current

- opens an unnamed connection that will persist for duration of

current backend or until it is disconnected

dblink_connect(text,text) RETURNS text

- opens a named connection that will persist for duration of current

backend or until it is disconnected

dblink_disconnect() RETURNS text

- disconnects a persistent connection

- disconnects the unnamed persistent connection

dblink_disconnect(text) RETURNS text

- disconnects a named persistent connection

cursor

------------

dblink_open(text,text) RETURNS text

- opens a cursor using connection already opened with dblink_connect()

that will persist for duration of current backend or until it is

closed

- opens a cursor using unnamed connection already opened with

dblink_connect() that will persist for duration of current backend

or until it is closed

dblink_open(text,text,text) RETURNS text

- opens a cursor using a named connection already opened with

dblink_connect() that will persist for duration of current backend

or until it is closed

dblink_fetch(text, int) RETURNS setof record

- fetches data from an already opened cursor

- fetches data from an already opened cursor on the unnamed connection

dblink_fetch(text, text, int) RETURNS setof record

- fetches data from an already opened cursor on a named connection

dblink_close(text) RETURNS text

- closes a cursor

- closes a cursor on the unnamed connection

dblink_close(text,text) RETURNS text

- closes a cursor on a named connection

query

------------

dblink(text,text) RETURNS setof record

- returns a set of results from remote SELECT query

(Note: comment out in dblink.sql to use deprecated version)

- returns a set of results from remote SELECT query; the first argument

is either a connection string, or the name of an already opened

persistant connection

dblink(text) RETURNS setof record

- returns a set of results from remote SELECT query, usingconnection

already opened with dblink_connect()

- returns a set of results from remote SELECT query, usingthe unnamed

connectionalready opened with dblink_connect()

execute

------------

dblink_exec(text, text) RETURNS text

- executes an INSERT/UPDATE/DELETE query remotely

- executes an INSERT/UPDATE/DELETE query remotely; the first argument

is either a connection string, or the name of an already opened

persistant connection

dblink_exec(text) RETURNS text

- executes an INSERT/UPDATE/DELETE query remotely, using connection

already opened with dblink_connect()

- builds an update statement using a local tuple, replacing the

selection key field values with alternate supplied values

Not installed by default

deprecated

------------

dblink(text,text) RETURNS setof int

- *DEPRECATED* returns a resource id for results from remote query

(Note: must uncomment in dblink.sql to use)

dblink_tok(int,int) RETURNS text

- *DEPRECATED* extracts and returns individual field results; used

only in conjunction with the *DEPRECATED* form of dblink

(Note: must uncomment in dblink.sql to use)

dblink_last_oid(int) RETURNS oid

- *DEPRECATED* returns the last inserted oid

Documentation:

Note: Parameters representing relation names must include double