TCS Senior Engineer Interview Questions and Answers for Freshers

PL/SQL exceptions handle errors and manage control flow in Oracle databases, ensuring robust application behavior.

• PL/SQL has predefined exceptions like NO_DATA_FOUND and ZERO_DIVIDE.

• Custom exceptions can be defined using the EXCEPTION keyword.

• Use the RAISE statement to trigger an exception manually.

• Example: BEGIN SELECT salary INTO v_salary FROM employees WHERE emp_id = 100; EXCEPTION WHEN NO_DATA_FOUND THEN DBMS_OUTPU...read more

PL/SQL triggers are special procedures that automatically execute in response to certain events on a database table or view.

• 1. DML Triggers: Execute on Data Manipulation Language events (INSERT, UPDATE, DELETE). Example: AFTER INSERT trigger to log changes.

• 2. INSTEAD OF Triggers: Used on views to perform actions instead of the triggering action. Example: INSTEAD OF DELETE on a view.

• 3. System Triggers: Triggered by syst...read more

Binary search is a fast search algorithm that finds the position of a target value within a sorted array.

• Ensure the array is sorted before performing binary search.

• Compare the target value with the middle element of the array.

• If the target value is less than the middle element, search the left half of the array. If greater, search the right half.

• Repeat the process until the target value is found or the subarray is empt...read more

Merge sort is a divide and conquer algorithm that divides the input array into two halves, sorts them, and then merges them back together.

• Divide the array into two halves recursively

• Sort each half separately

• Merge the sorted halves back together