Question

Fill in with the correct answers:
1. The ________ of each relation schema R in a database can not have NULL values in any tuple of r(R).

2. Whenever the database is changed, a new _____ arises.

3. ______ operation may violate only referential integrity.

4. In relational database, a special _________ value is used to represent values that are unknown or inapplicable to certain tuples.

Answer 1

Answer:

1.word

2.state

3.The delete operation canviolate only referential integrity.

4.null

Hope It Helps

Mark As Brainiest

Answer 2

Tuples are immutable i.e the value cannot be changed. So, Option D is correct.