DBLINK_OPEN(3)                    PostgreSQL 12.3 Documentation                    DBLINK_OPEN(3)



NAME
       dblink_open - opens a cursor in a remote database

SYNOPSIS
       dblink_open(text cursorname, text sql [, bool fail_on_error]) returns text
       dblink_open(text connname, text cursorname, text sql [, bool fail_on_error]) returns text

DESCRIPTION
       dblink_open() opens a cursor in a remote database. The cursor can subsequently be
       manipulated with dblink_fetch() and dblink_close().

ARGUMENTS
       connname
           Name of the connection to use; omit this parameter to use the unnamed connection.

       cursorname
           The name to assign to this cursor.

       sql
           The SELECT statement that you wish to execute in the remote database, for example
           select * from pg_class.

       fail_on_error
           If true (the default when omitted) then an error thrown on the remote side of the
           connection causes an error to also be thrown locally. If false, the remote error is
           locally reported as a NOTICE, and the function's return value is set to ERROR.

RETURN VALUE
       Returns status, either OK or ERROR.

NOTES
       Since a cursor can only persist within a transaction, dblink_open starts an explicit
       transaction block (BEGIN) on the remote side, if the remote side was not already within a
       transaction. This transaction will be closed again when the matching dblink_close is
       executed. Note that if you use dblink_exec to change data between dblink_open and
       dblink_close, and then an error occurs or you use dblink_disconnect before dblink_close,
       your change will be lost because the transaction will be aborted.

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

           SELECT dblink_open('foo', 'select proname, prosrc from pg_proc');
            dblink_open
           -------------
            OK
           (1 row)



PostgreSQL 12.3                                2020                                DBLINK_OPEN(3)