Sybase IQ supports referential integrity with RESTRICT action (the ANSI default) at the statement level.
This means that Sybase IQ denies requests for updates and deletes on the primary key or column(s) with a unique constraint that removes any value upon which correspondent foreign key(s) depend. (You must be careful about the order in which you request deletes and updates.) Sybase IQ issues an error message and rolls back load operations that violate referential integrity, but lets you specify that certain rows be ignored.