This tools enables to connect from PostgreSQL server to other databases. Currently it supports to connect to PostgreSQL, Oracle Database, MySQL, Sqlite3.
With dblink_plus, users can throw SQL to external databases like below:
=# BEGIN;
=# SELECT dblink.connect('ora_conn', 'server_oracle', false);
=# SELECT dblink.query('ora_conn', 'SELECT c1, c2 FROM tbl') AS t(c1 int, c2 text); -- get rows
=# SELECT dblink.exec('ora_conn', 'UPDATE tbl SET c3 = 999 WHERE c1=1'); -- modify rows
=# COMMIT;
Please take a look to documentation https://ossc-db.github.io/dblink_plus/index.html.