8.4 Using Dynamic Queries for Access Control
Once defined by the administrator, a dynamic query can be entered in most list header keywords used for access control or to enumerate e-mail addresses (see below for more information on security restrictions). Queries can be inserted wherever you would be allowed to enter an e-mail address, and have the following format:
The nickname is mandatory and must refer to an existing, pre-defined dynamic query. Parameters are optional and must be enclosed in true single quotes (ASCII hex 27) if they contain white space or commas. Do not use smart quotes or double quotes. Smart quotes are not recognized by LISTSERV, and double quotes have a special meaning in list header keywords and are generally removed from the keyword.
Tips: Remember that dynamic queries can fail at run time, for instance because the LDAP server is not available or because the DBMS login credentials have expired. A dynamic query is not a suitable method for defining, for instance, the primary editor of a mailing list, but it is perfect for adding large groups of people as secondary editors.
Try to put the dynamic query last in access control keywords. LISTSERV will only execute the query if none of the prior access control patterns were a match. It is always more efficient for LISTSERV to match a pattern like ‘*@example.com’ than to run a query against a DBMS or LDAP server.