Specifying edit procedures
If you plan to use an edit procedure, you can specify it when you create the table. However, you cannot add an edit procedure to an existing table, or alter a table with an edit procedure to add a column; you must drop and re-create the table.
Procedure
Specify the EDITPROC clause of the CREATE TABLE statement,
followed by the name of the procedure. The procedure is loaded on
demand during operation. 
You
can specify the EDITPROC clause on a table that is activated with
row and column access control. The rows of the table are passed to
these procedures if your security administrator determines that these
procedures are allowed to access sensitive data. 
You
can specify the EDITPROC clause on a table that is activated with
row and column access control. The rows of the table are passed to
these procedures if your security administrator determines that these
procedures are allowed to access sensitive data.