F.11. dblink
- dblink_connect — opens a persistent connection to a remote database
- dblink_connect_u — opens a persistent connection to a remote database, insecurely
 - dblink_disconnect — closes a persistent connection to a remote database
 - dblink — executes a query in a remote database
 - dblink_exec — executes a command in a remote database
 - dblink_open — opens a cursor in a remote database
 - dblink_fetch — returns rows from an open cursor in a remote database
 - dblink_close — closes a cursor in a remote database
 - dblink_get_connections — returns the names of all open named dblink connections
 - dblink_error_message — gets last error message on the named connection
 - dblink_send_query — sends an async query to a remote database
 - dblink_is_busy — checks if connection is busy with an async query
 - dblink_get_notify — retrieve async notifications on a connection
 - dblink_get_result — gets an async query result
 - dblink_cancel_query — cancels any active query on the named connection
 - dblink_get_pkey — returns the positions and field names of a relation's primary key fields
 - dblink_build_sql_insert — builds an INSERT statement using a local tuple, replacing the primary key field values with alternative supplied values
 - dblink_build_sql_delete — builds a DELETE statement using supplied values for primary key field values
 - dblink_build_sql_update — builds an UPDATE statement using a local tuple, replacing the primary key field values with alternative supplied values
  - dblink_connect_u — opens a persistent connection to a remote database, insecurely
 
dblink is a module that supports connections to other PostgreSQL databases from within a database session. 
See also postgres_fdw, which provides roughly the same functionality using a more modern and standards-compliant infrastructure.