Oracle: Test whether string is numeric

LENGTH(TRIM(TRANSLATE(string1, ' +-.0123456789', ' '))) IS NULL

See http://www.techonthenet.com/oracle/questions/isnumeric.php

Oracle: How to display information about network and ACL assignments

SELECT host, lower_port, upper_port, acl FROM dba_network_acls;

See Fine-Grained Access to Network Services in Oracle Database 11g