Under which two circumstances do you design database triggers? (Choose two)
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a) To duplicate the functionality of other triggers.
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b) To replicate built-in constraints in the Oracle server such as primary key and foreign key.
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c) To guarantee that when a specific operation is performed, related actions are performed.
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d) For centralized, global operations that should be fired for the triggering statement, regardless of which user or application issues the statement.
Database triggers are designed for two key purposes: (1) ensuring related actions occur when specific operations happen (data integrity and automation), and (2) implementing centralized global operations that fire regardless of which user or application invokes the statement (cross-cutting concerns). You should NOT duplicate other triggers' functionality or replicate built-in constraints like primary/foreign keys - those are anti-patterns.
To answer this question, you need to understand the purpose and functionality of database triggers. Let's go through each option to understand why it is correct or incorrect:
Option A) To duplicate the functionality of other triggers - This option is incorrect. Triggers are not designed to duplicate the functionality of other triggers. Instead, triggers are used to perform specific actions when certain events occur in the database.
Option B) To replicate built-in constraints in the Oracle server such as primary key and foreign key - This option is incorrect. Built-in constraints such as primary key and foreign key are not replicated using triggers. Constraints are separate database objects that enforce data integrity rules.
Option C) To guarantee that when a specific operation is performed, related actions are performed - This option is correct. One of the main purposes of database triggers is to ensure that when a specific operation (such as an insert, update, or delete) is performed on a table, related actions are automatically performed. These related actions can include updating data in other tables, sending notifications, or performing calculations.
Option D) For centralized, global operations that should be fired for the triggering statement, regardless of which user or application issues the statement - This option is correct. Database triggers can be used to perform centralized, global operations that should be executed whenever a specific triggering statement is issued, regardless of the user or application that issues the statement. This allows for consistent and standardized behavior across the database.
The correct answer is C and D. These options correctly describe the circumstances under which database triggers are designed.