Provided by: postgresql-doc-10_10.23-0ubuntu0.18.04.2_all 

NAME
dblink_get_connections - returns the names of all open named dblink connections
SYNOPSIS
dblink_get_connections() returns text[]
DESCRIPTION
dblink_get_connections returns an array of the names of all open named dblink connections.
RETURN VALUE
Returns a text array of connection names, or NULL if none.
EXAMPLES
SELECT dblink_get_connections();