F.11. dblink — connect to other PostgreSQL databases #

   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 is a module that supports connections to other PostgreSQL
   databases from within a database session.

   dblink can report the following wait events under the wait event type
   Extension.

   DblinkConnect
          Waiting to establish a connection to a remote server.

   DblinkGetConnect
          Waiting to establish a connection to a remote server when it
          could not be found in the list of already-opened connections.

   DblinkGetResult
          Waiting to receive the results of a query from a remote server.

   See also postgres_fdw, which provides roughly the same functionality
   using a more modern and standards-compliant infrastructure.