Cascading referential actions are costly because they cause updates to multiple tables for every transaction and this affects performance. For example, if the foreign key from Employees to Departments was defined with ON UPDATE CASCADE, then updating a department ID would automatically update the Employees table. While cascading referential actions are convenient, sometimes it might be more efficient to implement them in application logic instead.
Discuss this page in DocCommentXchange.
|Copyright © 2014, SAP AG or an SAP affiliate company. - SAP Sybase SQL Anywhere 16.0|