DBLINK_CONNECT(3)

πŸ“¦ version 14.24, in opensuse-leap 16.0

okay so first things first, this is a PostgreSQL 14.24 situation, and we're about to become besties with dblink_connect ✨


🌸 NAME 🌸

dblink_connect β€” opens a persistent connection to a remote database, no cap πŸ’…


πŸŽ€ SYNOPSIS πŸŽ€

dblink_connect(text connstr) returns text
dblink_connect(text connname, text connstr) returns text

πŸ¦‹ DESCRIPTION πŸ¦‹

okay so dblink_connect() literally establishes a connection to a remote PostgreSQL database. The server and database you're contacting are identified through a standard libpq connection string. Optionally, you can assign a name to the connection. Multiple named connections can be open at once, but only one unnamed connection is permitted at a time. The connection will persist until closed or until the database session is ended, periodt πŸ’«

The connection string may also be the name of an existing foreign server. It is recommended to use the foreign-data wrapper dblink_fdw when defining the foreign server. See the example below, as well as CREATE SERVER (CREATE_SERVER(7)) and CREATE USER MAPPING (CREATE_USER_MAPPING(7)). iykyk πŸ‘‘


✨ ARGUMENTS ✨

  • connname β€” the name to use for this connection; if omitted, an unnamed connection is opened, replacing any existing unnamed connection. it's giving main character energy, but just one at a time bestie πŸ™ˆ
  • connstr β€” libpq-style connection info string, for example hostaddr=127.0.0.1 port=5432 dbname=mydb user=postgres password=mypasswd options=-csearch_path=. For details see Section 34.1.1. Alternatively, the name of a foreign server. slay πŸ”₯

πŸ’€ RETURN VALUE πŸ’€

Returns status, which is always OK (since any error causes the function to throw an error instead of returning). no half-measures, it's either iconic or it's an error bestie πŸ’…


🌈 NOTES 🌈

If untrusted users have access to a database that has not adopted a secure schema usage pattern, begin each session by removing publicly-writable schemas from search_path. One could, for example, add options=-csearch_path= to connstr. This consideration is not specific to dblink; it applies to every interface for executing arbitrary SQL commands. pls don't skip this one, it's important 🫢

Only superusers may use dblink_connect to create non-password-authenticated connections. If non-superusers need this capability, use dblink_connect_u instead. the privilege check said what it said πŸ’€

It is unwise to choose connection names that contain equal signs, as this opens a risk of confusion with connection info strings in other dblink functions. like, just don't, okay? 😭


🧚 EXAMPLES 🧚

SELECT dblink_connect('dbname=postgres options=-csearch_path=');
 dblink_connect
----------------
 OK
(1 row)

SELECT dblink_connect('myconn', 'dbname=postgres options=-csearch_path=');
 dblink_connect
----------------
 OK
(1 row)

-- FOREIGN DATA WRAPPER functionality
-- Note: local connection must require password authentication for this to work properly
--       Otherwise, you will receive the following error from dblink_connect():
--       ERROR:  password is required
--       DETAIL:  Non-superuser cannot connect if the server does not request a password.
--       HINT:  Target server's authentication method must be changed.

CREATE SERVER fdtest FOREIGN DATA WRAPPER dblink_fdw OPTIONS (hostaddr '127.0.0.1', dbname 'contrib_regression');

CREATE USER regress_dblink_user WITH PASSWORD 'secret';
CREATE USER MAPPING FOR regress_dblink_user SERVER fdtest OPTIONS (user 'regress_dblink_user', password 'secret');
GRANT USAGE ON FOREIGN SERVER fdtest TO regress_dblink_user;
GRANT SELECT ON TABLE foo TO regress_dblink_user;

\set ORIGINAL_USER :USER
\c - regress_dblink_user
SELECT dblink_connect('myconn', 'fdtest');
 dblink_connect
----------------
 OK
(1 row)

SELECT * FROM dblink('myconn', 'SELECT * FROM foo') AS t(a int, b text, c text[]);
 a  | b |       c
----+---+---------------
  0 | a | {a0,b0,c0}
  1 | b | {a1,b1,c1}
  2 | c | {a2,b2,c2}
  3 | d | {a3,b3,c3}
  4 | e | {a4,b4,c4}
  5 | f | {a5,b5,c5}
  6 | g | {a6,b6,c6}
  7 | h | {a7,b7,c7}
  8 | i | {a8,b8,c8}
  9 | j | {a9,b9,c9}
 10 | k | {a10,b10,c10}
(11 rows)

\c - :ORIGINAL_USER
REVOKE USAGE ON FOREIGN SERVER fdtest FROM regress_dblink_user;
REVOKE SELECT ON TABLE foo FROM regress_dblink_user;
DROP USER MAPPING FOR regress_dblink_user SERVER fdtest;
DROP USER regress_dblink_user;
DROP SERVER fdtest;

quick vibe check: that whole FOREIGN DATA WRAPPER example is lowkey doing the most, but it's literally the blueprint for secure foreign server connections, so study it bestie πŸŽ€

and that's the tea! β˜• this little icon was brought to you by PostgreSQL 14.24, dated 2026, and it's truly giving documentation excellence πŸ’– see you in the next manpage, bestie! πŸŒΈπŸ¦‹βœ¨

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