dblink_error_message - gets last error message on the named connection
dblink_error_message(text connname) returns text
dblink_error_message fetches the most recent remote error message for a
given connection.
connname
Name of the connection to use.
Returns last error message, or OK if there has been no error in this connection.
When asynchronous queries are initiated by dblink_send_query, the error
message associated with the connection might not get updated until the
server's response message is consumed. This typically means that
dblink_is_busy or dblink_get_result should be called prior to
dblink_error_message, so that any error generated by the asynchronous
query will be visible.
SELECT dblink_error_message('dtest1');