Cascade rules: which statement is true?

Cascade rules: which statement is true?

• A. Delete cascade is recommended
• B. Remove cascade constraints is advised
• C. No cascading should ever be used
• D. Update cascade is recommended

Answer: (D)

Cascading rules define how changes in a parent record propagate to related child records. When a key in the parent is updated, an update cascade automatically updates the corresponding foreign key values in the dependent rows, keeping all references in sync and preventing orphaned or inconsistent data. This minimizes manual intervention and reduces the risk of errors that can occur when updates are done individually across many child rows. Deleting with cascade can be dangerous because it may remove large amounts of data unintentionally, which is why it isn’t generally recommended as the default approach. Removing cascade constraints would stop enforcing referential integrity, leading to possible orphaned child records. Saying no cascading should ever be used is too absolute, since in some controlled scenarios cascading updates (and even deletes) can preserve consistency and simplify maintenance. Thus, updating cascades are prioritized for maintaining referential integrity during updates, which is why this statement is considered true.

Cascading rules define how changes in a parent record propagate to related child records. When a key in the parent is updated, an update cascade automatically updates the corresponding foreign key values in the dependent rows, keeping all references in sync and preventing orphaned or inconsistent data. This minimizes manual intervention and reduces the risk of errors that can occur when updates are done individually across many child rows.

Deleting with cascade can be dangerous because it may remove large amounts of data unintentionally, which is why it isn’t generally recommended as the default approach. Removing cascade constraints would stop enforcing referential integrity, leading to possible orphaned child records. Saying no cascading should ever be used is too absolute, since in some controlled scenarios cascading updates (and even deletes) can preserve consistency and simplify maintenance.

Thus, updating cascades are prioritized for maintaining referential integrity during updates, which is why this statement is considered true.