CSC Global Interview Questions and Answers

Delete removes specific rows from a table, truncate removes all rows from a table, and drop removes an entire table.

• Delete is a DML command, while truncate and drop are DDL commands.

• Delete can be rolled back, while truncate and drop cannot be rolled back.

• Delete is slower than truncate and drop as it logs individual row deletions.

• Delete can have a WHERE clause to specify conditions, while truncate and drop do not support conditions.

• Example: DELETE FROM table_name WHERE conditi...read more

Parameterized constructor accepts parameters to initialize an object, while copy constructor creates a new object by copying an existing object.

• Parameterized constructor is used to initialize an object with specific values.

• Copy constructor creates a new object by copying values from an existing object.

• Example: Parameterized constructor - Car(int year, String model) { this.year = year; this.model = model; }

• Example: Copy constructor - Car(Car otherCar) { this.year = otherCar.ye...read more

2 way merge sort involves splitting the array into 2 parts and merging them, while 3 way merge sort involves splitting the array into 3 parts and merging them.

• 2 way merge sort splits the array into 2 parts and merges them recursively.

• 3 way merge sort splits the array into 3 parts and merges them recursively.

• 2 way merge sort has a time complexity of O(n log n), same as 3 way merge sort.

Polymorphism is the ability of an object to take on many forms. It allows objects of different classes to be treated as the same type.

• Polymorphism is a fundamental concept in object-oriented programming.

• It allows a single interface to be used for different types of objects.

• Polymorphism is achieved through method overriding and method overloading.

• Example: A parent class Animal can have multiple child classes like Dog, Cat, and Bird. They can all be treated as Animals.

• Polymorph...read more

Join types in SQL are used to combine rows from two or more tables based on a related column between them.

• Inner join: returns only the matching rows from both tables

• Left join: returns all rows from the left table and the matching rows from the right table

• Right join: returns all rows from the right table and the matching rows from the left table

• Full outer join: returns all rows from both tables, including the unmatched rows

• Cross join: returns the Cartesian product of both tabl...read more